The synthesis of an RNA molecule from a DNA template is called

transcription

Note: RNA is synthesized from DNA by an enzyme known as RNA polymerase during a process called transcription.

Structural genes are also known as ____-encoding genes.

protein

In prokaryotes, a protein-encoding gene is first transcribed into an RNA molecule called ____ RNA.

messenger

In eukaryotes, the first product of a protein-encoding gene is a(n) ______.

Multiple choice question.

tRNA molecule

polypeptide molecule

rRNA molecule

primary mRNA transcript

primary mRNA transcript

Which is the proper matching of template and synthesized product for the process of translation?

Multiple choice question.

RNA template; DNA product

DNA template; protein product

DNA template; RNA product

RNA template; protein product

RNA template; protein product

The central dogma of genetics can be summed up by which of the following?

Multiple choice question.

mRNA → polypeptide → DNA

mRNA → DNA → polypeptide

polypeptide → mRNA → DNA

DNA → polypeptide → mRNA

DNA → mRNA → polypeptide

DNA → mRNA → polypeptide

In transcription, a(n) ______ template is used to synthesize ______.

Multiple choice question.

DNA; protein

DNA; RNA

RNA; protein

RNA; DNA

DNA; RNA

At the molecular level, ______ is the process by which a gene's information is used to produce a polypeptide or functional RNA molecule.

Multiple choice question.

genomic editing

genomic imprinting

gene expression

gene manifestation

gene expression

A structural gene encodes a(n) ______.

Multiple choice question.

polypeptide

tRNA molecule

rRNA molecule

polypeptide

The sequence in DNA that signals the end of transcription is known as the

terminator

The sequence of a gene's DNA that is transcribed extends from the end of the ____ to the end of the ____.

promoter; terminator

The synthesis of a polypeptide molecule from an mRNA template is called

translation

Note: Translation is the synthesis of polypeptide/ protein by polymerization of amino acids using mRNA sequence as template; it is carried out on ribosomes and tRNA serves to carry amino acids from cell pool to mRNA.

The strand of DNA that is used to produce the RNA transcript is called the ______ strand, while the opposite strand of DNA is called the ______ strand or non-template.

Multiple choice question.

coding; noncoding

template; coding

coding; template

noncoding; template

template; coding

Note: In transcription, a region of DNA opens up. One strand, the template strand, serves as a template for synthesis of a complementary RNA transcript. The other strand, the coding strand, is identical to the RNA transcript in sequence, except that it has uracil (U) bases in place of thymine (T) bases.

The flow of genetic information in a cell, from DNA to RNA to protein, is described as the ____ ____ of genetics.

central dogma

The nontemplate strand is also called the coding strand because it ______.

Multiple choice question.

has the same sequence as the mRNA but with A's instead of T's

is complementary and antiparallel to the mRNA

is complementary and parallel to the mRNA

has the same sequence as the mRNA but with T's instead of U's

has the same sequence as the mRNA but with A's instead of U's

has the same sequence as the mRNA but with T's instead of U's

The overall process by which the information within a gene is used to produce a functional product is called ____ ____.

gene expression

Note: Gene expression is the process by which the information encoded in a gene is turned into a function. This mostly occurs via the transcription of RNA molecules that code for proteins or non-coding RNA molecules that serve other functions.4 days ago

To which will proteins known as transcription factors bind and what is the outcome?

Multiple choice question.

DNA sequences to facilitate transcription

RNA molecules after transcription in order to enhance their conversion into proteins

RNA molecules during transcription in order to stabilize them

RNA polymerase to control transcription

DNA sequences to facilitate transcription

Which best describes a terminator of a gene?

Multiple choice question.

DNA sequence that specifies the end of translation

Molecule that binds to RNA polymerase to end RNA synthesis

Molecule that binds to a ribosome to end protein synthesis

DNA sequence that specifies the end of transcription

DNA sequence that specifies the end of transcription

Short stretches of DNA that are involved in the regulation of transcription are known as regulatory sequences or regulatory

elements

In a gene, the DNA is transcribed into RNA from the ______ to the ______.

Multiple choice question.

promoter; terminator

start codon; terminator

start codon; stop codon

promoter; stop codon

promoter; terminator

The ribosome-binding site is a sequence in bacterial ______ that is involved in ______.

Multiple choice question.

mRNA ; translation termination

mRNA ; translation initiation

DNA ; transcription termination

DNA ; transcription initiation

mRNA ; translation initiation

The base sequence of the RNA transcript is complementary to the ____ strand of DNA.

template, noncoding, or antisense

Note: RNA polymerase synthesizes an RNA transcript complementary to the DNA template strand in the 5' to 3' direction. It moves forward along the template strand in the 3' to 5' direction, opening the DNA double helix as it goes.

In bacteria, the ribosome-binding site is also called the ____-____ sequence.

Shine-Dalgarno

Note: In prokaryotes, the ribosome binding site (RBS), which promotes efficient and accurate translation of mRNA, is called the Shine-Dalgarno sequence after the scientists that first described it.

For protein-encoding genes, the nontemplate strand is also called the ____ strand.

coding or sense

Note: The nontemplate strand is referred to as the coding strand because its sequence will be the same as that of the new RNA molecule.

The mRNA contains groups of three nucleotides that specify the amino acid sequence of a polypeptide. These three-nucleotide groups are called

codons

Note: Each group of three consecutive nucleotides in RNA is called a codon, and each codon specifies either one amino acid or a stop to the translation process.

Proteins that bind to DNA and facilitate RNA synthesis are collectively called ____ ____.

transcription factors

Note: Proteins that bind to DNA and facilitate RNA synthesis are collectively called. Transcription factors. Following the binding of RNA pol to the promoter, the DNA is denatured into a bubble known as the. Open complex. What makes the transition to the elongation stage of transcription in bacteria.

The group of three nucleotides that signals the beginning of translation is called the ____ ____.

start codon or initiation codon

Note: A codon is a sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis.

Regulatory elements are short stretches of ______ involved in the regulation of ______.

Multiple choice question.

RNA ; translation

DNA ; transcription

RNA ; transcription

DNA ; translation

DNA ; transcription

In bacteria, a short sequence in the mRNA provides a location that recruits the machinery to start translation. This sequence is called the ____-____ site.

ribosome binding; shine-dalgarno

True or false: Transcription occurs in two stages: initiation and termination.

False

Reason: This is false: Transcription occurs in three stages: initiation, elongation and termination.

The Shine-Dalgarno sequence is a short sequence in the ______ which provides a location for the binding of ______.

Multiple choice question.

mRNA of bacteria ; ribosomes

DNA of bacteria ; RNA polymerases

DNA of eukaryotes ; RNA polymerases

mRNA of eukaryotes ; ribosomes

mRNA of bacteria ; ribosomes

A triplet of nucleotides that corresponds to an amino acid is known as a(n) ______.

Multiple choice question.

operon

intron

codon

exon

codon

Note: The mRNA contains groups of three nucleotides that specify the amino acid sequence of a polypeptide. These three-nucleotide groups are called codons.

The enzyme that synthesizes RNA from a DNA template is called ____ ____.

RNA polymerase

The end of protein synthesis is specified by a ____ ____, which is a triplet of nucleotides in the mRNA molecule.

stop codon

Transcription is initiated by the binding of one or more transcription factors to the ____ region of a gene.

promoter

What is a promoter?

Multiple choice question.

A specific target sequence to which RNA polymerase binds.

An element that facilitates termination of transcription.

An environmental chemical that induces gene expression.

A regulatory protein that accelerates mRNA turnover.

A specific target sequence to which RNA polymerase binds.

The three stages of transcription are called ____, ____, and ____.

initiation

elongation

termination

The transcriptional start site is denoted as ______.

Multiple choice question.

-1

0

+1

+1

The first nucleotide that acts as a template for transcription is designated with the number ____. The nucleotides preceding this site are numbered in a(n) ____ direction, while those that come after it are numbered in a positive direction.

+1; negative

Which enzyme synthesizes RNA during transcription?

Multiple choice question.

RNA polymerase

RNA replicase

DNA replicase

DNA polymerase

RNA polymerase

Select all that apply

Which sequences of bacterial promoters are particularly important for transcription initiation?

Multiple select question.

The -10 site: 5' TTGACA 3'

The -10 site: 5' TATAAT 3'

The -35 site: 5' TATAAT 3'

The -35 site: 5' TTGACA 3'

The -25 site: 5' TTGACA 3'

The -25 site: 5' TATAAT 3'

The -10 site: 5' TATAAT 3'

The -35 site: 5' TTGACA 3'

Following the binding of RNA polymerase to the promoter, the DNA is denatured into a bubble known as the ____ ____.

open complex

Note: RNA polymerase can only make RNA by attaching to DNA and separating the two strands of the DNA double helix. This creates a short region of single-stranded DNA known as a “transcription bubble” or open complex.

The association of a sigma factor with the core enzyme forms a complex referred to as the RNA polymerase ____.

holoenzyme

The sequence in DNA that signals RNA polymerase where to begin transcription is called the

promoter

Note: A DNA sequence at which the RNA polymerase binds to start transcription is called a promoter.

The RNA polymerase holoenzyme is composed of several subunits including sigma factor whose primary role is to recognize the

promoter

The first DNA base used as a template for RNA synthesis is called the ____ ____ site.

transcriptional start

This diagram shows the ______ stage of transcription in ______.

Multiple choice question.

initiation; eukaryotes

elongation; bacteria

initiation; bacteria

elongation; eukaryotes

initiation; bacteria

(figure 12.7 the initiation stage of transcription in bacteria)

The following numbers represent the order of nucleotides in a bacterial promoter, going from left to right. Which of these is a correct representation of the conventional numbering system?

Multiple choice question.

-5 -4 -3 -2 -1 +1 +2 +3 +4 +5

-5 -4 -3 -2 -1 0 +1 +2 +3 +4 +5

+5 +4 +3 +2 +1 0 -1 -2 -3 -4 -5

+5 +4 +3 +2 +1 -1 -2 -3 -4 -5

-5 -4 -3 -2 -1 +1 +2 +3 +4 +5

Which regions of a bacterial promoter play a key role in promoting transcription?

Multiple choice question.

-35 and -10

-25 and +1

-100 and -10

-35 and -75

-75 and -35

-35 and -10

The term closed complex refers to what?

Multiple choice question.

The binding of the RNA polymerase core enzyme to the DNA

The final binding of the DNA to the newly-synthesized mRNA

The binding of the ribosome to the mRNA to initiate translation

The initial binding of the RNA polymerase holoenzyme to the promoter

The initial binding of the RNA polymerase holoenzyme to the promoter

In E. coli, the RNA polymerase holoenzyme is composed of the ______ plus ______.

Multiple choice question.

apoenzyme; sigma factor

core enzyme; rho factor

core enzyme; sigma factor

sigma factor; rho factor

apoenzyme; rho factor

core enzyme; sigma factor

What marks the transition to the elongation stage of transcription in bacteria?

Multiple choice question.

The formation of an open complex between RNA pol and DNA

The release of the sigma factor from the RNA pol holoenzyme

The release of the rho factor from the RNA pol holoenzyme

The formation of a closed complex between RNA pol and DNA

The release of the sigma factor from the RNA pol holoenzyme

Match the subunit of the bacterial RNA polymerase to its appropriate function.

α₂

β and β'

ω

σ

Proper assembly of the holoenzyme

Proper assembly of the core enzyme

Recognition of the promoter

Catalytic synthesis of the RNA

• α2 Proper assembly of the holoenzyme
• β and β' Catalytic synthesis of the RNA
• ω Proper assembly of the core enzyme
• σ Recognition of the promoter

The initiation stage of bacterial transcription is shown in this figure. Match the letter to its appropriate description.

A

B

C

D

Open complex

RNA polymerase core enzyme

Closed complex

Sigma factor

• A Closed complex
• B Open complex
• C Sigma factor
• D RNA polymerase core enzyme

RNA polymerase catalyzes the formation of a bond between the ______ group of one nucleotide and the ______ group on the previous nucleotide.

Multiple choice question.

5' phosphate; 3' hydroxyl

3' phosphate; 5' hydroxyl

3' hydroxyl; 5' phosphate

5' hydroxyl; 3' phosphate

5' phosphate; 3' hydroxyl

Part of the coding region of a gene is shown here: 5'-TTCCCATTTCGATGGGATACGATGG-3' 3'-AAGGGTAAAGCTACCCTATGCTACC-5' What is the sequence of the transcribed mRNA, assuming transcription proceeds left to right?

Multiple choice question.

5'-UUCCCAUUUCGAUGGGAUACGAUGG-3'

5'-AAGGGUAAAGCUACCCUAUGCUACC-3'

3'-UUCCCAUUUCGAUGGGAUACGAUGG -3'

3'-AAGGGUAAAGCUACCCUAUGCUACC-5'

5'-TTCCCATTTCGATGGGATACGATGG-3'

5'-UUCCCAUUUCGAUGGGAUACGAUGG-3'

Transcription in E. coli is initiated when the sigma factor of the RNA polymerase holoenzyme binds to the promoter region to form a(n) ____ ____.

closed cpmplex

During transcription, a T on the template DNA strand is paired with a(n) ____ in the mRNA, and an A on the template DNA strand is paired with a(n) ____ in the mRNA.

adenine or A

uracil, U, or Uracil

The transition from the initiation to the elongation phase of bacterial transcription is marked by the release of the

sigma factor

Note: the transition from initiation to elongation modes is marked by the release of the σ factor from the core polymerase

The template strand is read in the ______ direction, and the synthesis of the RNA transcript occurs in a ______ direction.

Multiple choice question.

3'-to-5'; 3'-to-5'

5'-to-3'; 5'-to-3'

3'-to-5'; 5'-to-3'

5'-to-3'; 3'-to-5'

3'-to-5'; 5'-to-3'

Select all that apply

Which of the following are the two mechanisms of transcription termination in E. coli?

Multiple select question.

Energy-dependent termination

Rho-dependent termination

Sigma-independent termination

Rho-independent termination

Energy-independent termination

Sigma-dependent termination

Rho-dependent termination

Rho-independent termination

During transcription, RNA is synthesized in what direction?

Multiple choice question.

5' to 3' for all genes

3' to 5' for some genes, and 5' to 3' for other genes

3' to 5' in prokaryotes, and 5' to 3' in eukaryotes

3' to 5' for all genes

5' to 3' in prokaryotes, and 3' to 5' in eukaryotes

5' to 3' for all genes

In E. coli, the transcription termination of certain genes requires an RNA-binding protein called

Rho or rho protein

Escherichia coli protein Rho is required for the factor-dependent transcription termination by an RNA polymerase and is essential for the viability of the cell. It is a homohexameric protein that recognizes and binds preferably to C-rich sites in the transcribed RNA.

The template strand of a gene has the sequence: 5'-ATTGCC-3'. What is the sequence of the transcribed mRNA?

Multiple choice question.

5'-GGCAAU-3'

5'-UAACGG-3'

5'-UAAGCC-3'

5'-AUUGCC-3'

5'-GCCAAU-3'

5'-CCGUUA-3'

5'-GGCAAU-3'

The complementarity rule used in transcription is similar to the ______ rule, except that ______ substitutes for thymine in the RNA.

Multiple choice question.

AG/CT; inosine

AG/CT; uracil

AT/GC; uracil

AT/GC; inosine

AT/GC; uracil

The formation of a stem-loop structure and the requirement for a helicase are characteristic of bacterial genes that undergo ____-____ termination of transcription.

rho dependent

In a chromosome, which of the following statements is TRUE?

Multiple choice question.

Different genes can be transcribed off either strand of the double helix, some in the 5′ --> 3′ direction and some in the 3′ --> 5′ direction.

The mRNAs of different genes can be transcribed off either DNA strand of the double helix, but always synthesized in the 3′ --> 5′ direction.

The mRNAs of all genes are synthesized 5′ --> 3′ off the same DNA strand of the double helix.

The mRNAs of all genes are synthesized 3′ --> 5′ off the same DNA strand of the double helix.

The mRNAs of different genes can be transcribed off either DNA strand of the double helix, but always synthesized in the 5′ --> 3′ direction.

The mRNAs of different genes can be transcribed off either DNA strand of the double helix, but always synthesized in the 5′ --> 3′ direction.

A stem-loop structure followed by a stretch of U nucleotides in the 3'-end of a bacterial mRNA are characteristic of genes that undergo ______.

Multiple choice question.

rho-dependent termination of transcription

alternative splicing and RNA editing

rho-independent termination of transcription

capping and polyadenylation

rho-independent termination of transcription

E. coli employs two different mechanisms for transcription termination. One requires an RNA -binding protein and is called ____-____ termination. The mechanism that does not involve this binding protein is called ____-____ termination.

rho-dependent; rho-independent

Which of the following statements about eukaryotic RNA polymerases is true?

Multiple choice question.

RNA pol I transcribes most tRNAs; RNA pol II transcribes all mRNAs; RNA pol III transcribes all rRNAs

RNA pol I transcribes all mRNAs; RNA pol II transcribes most tRNAs; RNA pol III transcribes all rRNAs

RNA pol I transcribes all rRNAs; RNA pol II transcribes most mRNAs; RNA pol III transcribes all tRNAs

RNA pol I transcribes most rRNAs; RNA pol II transcribes all mRNAs; RNA pol III transcribes all tRNAs

RNA pol I transcribes most mRNAs; RNA pol II transcribes all tRNAs; RNA pol III transcribes most rRNAs

RNA pol I transcribes most rRNAs; RNA pol II transcribes all mRNAs; RNA pol III transcribes all tRNAs

The rho factor is most important for ______.

Multiple choice question.

synthesizing primers for transcription

rapid movement of the RNA polymerase along the DNA

binding of the RNA polymerase to the promoter

termination of transcription

proofreading of the mRNA by RNA polymerase

termination of transcription

In eukaryotic cells, the relatively short DNA sequence that is required for transcription to take place is known as the ____ ____.

core promoter

Select all that apply

The rho-dependent mechanism of transcription termination requires what?

Multiple select question.

The formation of a stem-loop structure

The presence of a stop codon in the mRNA

A uracil-rich sequence located at the 3' end of the mRNA

Helicase activity to separate the DNA-RNA complex

The formation of a stem-loop structure

Helicase activity to separate the DNA-RNA complex

The TATA box of eukaryotic genes is usually located about ______ from the transcriptional start site.

Multiple choice question.

35 bp upstream

25 bp downstream

25 bp upstream

10 bp downstream

10 bp upstream

25 bp upstream

Note: The TATA box is typically located 25 nucleotides upstream from the transcription start site.

Select all that apply

The rho-independent mechanism of transcription termination requires what?

Multiple select question.

A helicase to separate the DNA-RNA complex

The presence of a stop codon in the mRNA

A uracil-rich sequence located at the 3' end of the mRNA

The formation of a stem-loop structure

A uracil-rich sequence located at the 3' end of the mRNA

The formation of a stem-loop structure

Match the eukaryotic RNA polymerase to the category of genes it transcribes.

RNA polymerase I

RNA polymerase II

RNA polymerase III

The majority of rRNA genes

All protein-encoding genes

All tRNA genes and the 5S rRNA gene

• RNA polymerase I The majority of rRNA genes
• RNA polymerase II All protein-encoding genes
• RNA polymerase III All tRNA genes and the 5S rRNA gene

Basal transcription refers to the low level of transcription that ______.

Multiple choice question.

involves only the core promoter

involves regulatory elements called silencers

occurs in conditions of starvation

occurs in the 3' to 5' direction

involves only the core promoter

What is the core promoter?

Multiple choice question.

A relatively short DNA sequence that is necessary to terminate transcription

The region of the RNA pol holoenzyme that synthesizes the mRNA

The region of the RNA pol holoenzyme that binds to the DNA template strand

A relatively short DNA sequence that is necessary for transcription to take place

A relatively short DNA sequence that is necessary for transcription to take place

Which protein will recognize the promoter shown in the diagram?

Multiple choice question.

RNA polymerase III of eukaryotes

RNA polymerase of bacteria

RNA polymerase II of eukaryotes

RNA polymerase I of eukaryotes

RNA polymerase II of eukaryotes

Eukaryotic genes have two types of regulatory elements that influence the rate of transcription. These are called ____ and ____.

enhancers; silencers

For eukaryotic genes, the core promoter typically consists of a TATAAA sequence called the ____ box and the transcriptional start site.

TATA

What are enhancers?

Multiple choice question.

Regulatory elements in prokaryotes that stimulate transcription

Regulatory elements in eukaryotes that stimulate transcription

Proteins in prokaryotes that stimulate transcription

Proteins in eukaryotes that stimulate transcription

Regulatory elements in eukaryotes that stimulate transcription

A stem-loop structure followed by a stretch of U nucleotides in the 3'-end of a bacterial mRNA are characteristic of genes that undergo ______.

Multiple choice question.

capping and polyadenylation

rho-independent termination of transcription

rho-dependent termination of transcription

alternative splicing and RNA editing

rho-independent termination of transcription

What are silencers?

Multiple choice question.

Proteins in eukaryotes that inhibit transcription

Regulatory elements in eukaryotes that inhibit transcription

Proteins in prokaryotes that inhibit transcription

Regulatory elements in prokaryotes that inhibit transcription

Regulatory elements in eukaryotes that inhibit transcription

The low level of transcription caused by the presence of the core promoter by itself is known as ____ transcription.

basal

Select all that apply

What three categories of proteins are needed for basal transcription of protein-encoding genes in eukaryotes?

Multiple select question.

General transcription factors

RNA polymerase I

RNA polymerase II

Rho factors

Enhancer

Mediator

General transcription factors

RNA polymerase II

Mediator

This figure shows the promoter of a ______ gene of ______.

Multiple choice question.

structural; eukaryotes

nonstructural; prokaryotes

nonstructural; eukaryotes

structural; prokaryotes

structural; eukaryotes

General transcription factors are those that are ______.

Multiple choice question.

found in both prokaryotic and eukaryotic species

always needed for RNA pol II to initiate transcription

capable of stimulating or inhibiting transcription

always needed for RNA pol II to initiate transcription

What are the two types of regulatory elements that influence the rate of transcription in eukaryotes?

Multiple choice question.

Activators and inhibitors

Mediator-dependent and mediator-independent

Rho-dependent and rho-independent

Enhancers and silencers

Enhancers and silencers

The preinitiation complex is a(n) ______ complex that consists of RNA polymerase II and five general transcription factors.

Multiple choice question.

open complex

closed complex

closed complex

Regulatory elements that stimulate transcription are termed

enhancers

Regulatory elements that inhibit transcription are termed

silencers

In eukaryotic protein-encoding genes, three categories of proteins are required for basal transcription at the core promoter: RNA polymerase ____, general transcription ____, and a complex called mediator.

II; factors

Select all that apply

The basal transcription apparatus consists of what?

Multiple select question.

TFIID, TFIIB, TFIIF, TFIIE, and TFIIH

TATA box plus transcriptional start site

GC and CAAT boxes

RNA polymerase II

Enhancers and silencers

TFIID, TFIIB, TFIIF, TFIIE, and TFIIH

TATA box plus transcriptional start site

RNA polymerase II

For eukaryotic protein-encoding genes, the five proteins that are always needed for RNA polymerase II to initiate RNA synthesis are called ____ ____ factors.

general transcription

In eukaryotes, the protein complex called mediator facilitates the interaction between which of the following?

Multiple choice question.

the newly-synthesized mRNA and the DNA template strand during the elongation phase of transcription

RNA polymerase II and the general transcription factors that bind to the promoter

RNA polymerase II and regulatory transcription factors that bind to enhancers and silencers

RNA polymerase II and the TATAAT sequence of the core promoter

RNA polymerase II and regulatory transcription factors that bind to enhancers and silencers

Which of the following is the very first step in the formation of the preinitiation complex in eukaryotic transcription?

Multiple choice question.

Binding of RNA polymerase II to the TATA box

Binding of TFIID to the TATA box

Binding of TFIID to TFIIB

Binding of RNA polymerase II to TFIIF

Binding of TFIID to the TATA box

An exonuclease binds to the 5'-end of the RNA that is being transcribed and degrades it in the 5' to 3' direction. The exonuclease then catches up to RNA polymerase II and causes termination. This describes the ____ model of transcription termination in eukaryotes.

torpedo

Colinearity refers to the correspondence between ______.

Multiple choice question.

the coding strand and the noncoding strand

the position of a gene on a linear chromosome and when it is expressed

the exons and introns

the coding strand and the polypeptide amino acid sequences

Note: The relationship between the sequence of codons in DNA and the amino acid sequence of a peptide is known as colinearity.

True or false: Introns are intervening sequences that are removed from mRNA and exons are the retained sequences.

True

The combination of five general transcription factors, RNA polymerase II, and a DNA sequence containing a TATA box and a transcriptional start site is called the ______.

Multiple choice question.

mediator

promoter sequence

coding strand sequence

basal transcription apparatus

basal transcription apparatus

In eukaryotes, the interactions between RNA polymerase II and regulatory transcription factors that bind to enhancers and silencers are facilitated by a protein complex called

mediator

RNA splicing is a ______ process that removes ______.

Multiple choice question.

common; exons

common; introns

rare; introns

rare; exons

common; introns

After RNA polymerase II transcribes the polyadenylation signal, it is destabilized and dissociates from the DNA. This describes the ____ model of transcription termination in eukaryotes.

allosteric

Select all that apply

In humans, the long 45S rRNA transcript is cleaved to produce which of the following?

Multiple select question.

30S

15S

28S

11.2S

18S

5.8S

28S

18S

5.8S

The relationship between the sequence of codons in DNA and the amino acid sequence of a peptide is known as

colinearity

The nucleolus in eukaryotes is the site of processing of ______ RNA.

Multiple choice question.

transfer

messenger

ribosomal

small

ribosomal

Sequences that are included in mature mRNA are ____ and sequences that are removed are ____.

exons; introns

An enzyme that cleaves a covalent bond between two nucleotides at one end of a strand is called a(n)

exonuclease

An RNA molecule that has catalytic activity is called a(n)

ribozyme

Note: Ribozymes are catalytically active RNA molecules or RNA–protein complexes, in which solely the RNA provides catalytic activity. The term ribozyme refers to the enzymatic activity and ribonucleic acid nature at the same time. Ribozymes are found in the genomes of species from all kingdoms of life.

The process of removing introns and joining exons together is called RNA

splicing

Note: Removal of introns and joining the exons in a defined order in a transcription unit is called as splicing. Splicing is a modification of the nascent pre-messenger RNA transcript in which introns are removed and exons are joined.

Which of the following panels depict self-splicing introns?

Multiple choice question.

A, B, and C

A only

B only

A and B

C only

A and B

Note: Figure 12.18 Mechanisms of RNA splicing

In mammals, the ribosomal RNA gene is transcribed by RNA polymerase ____ to make a long primary transcript known as ____ rRNA. This transcript is then cleaved into ____ smaller fragments.

I; 45S; 3

In eukaryotes, the assembly of ribosomal subunits occurs in a site within the nucleus called the

nucleolus

Note: The nucleolus is a ribosome production factory, designed to fulfill the need for large-scale production of rRNAs and assembly of the ribosomal subunits.

The removal of introns where RNA functions as its own ribozyme is a process called ______-splicing.

Multiple choice question.

alternative

complementary

auto

self

self

An enzyme that cleaves a covalent bond between two adjacent nucleotides within a strand is called a(n)

endonuclease

Group I introns undergo a ______ process that is initiated by a(n) ______.

Multiple choice question.

spliceosome-mediated ; U1 molecule binding to the 3' splice site of the intron

self-splicing ; free guanosine outside the intron

spliceosome-mediated ; U1 molecule binding to the 5' splice site of the intron

self-splicing ; adenine found within the intron

self-splicing ; free guanosine outside the intron

Which best describes a ribozyme?

Multiple choice question.

A ribosome that contains many enzymes

An enzyme that digests RNA

An RNA molecule with catalytic activity

An enzyme that is activated upon binding RNA

An RNA molecule with catalytic activity

Group II introns undergo a ______ process that is initiated by a(n) ______.

Multiple choice question.

spliceosome-mediated ; U1 molecule binding to the 5' splice site of the intron

self-splicing ; free guanosine outside the intron

spliceosome-mediated ; U1 molecule binding to the 3' splice site of the intron

self-splicing ; adenine found within the intron

self-splicing ; adenine found within the intron

Match the letter to the correct intron.

A

B

C

Group I intron

Group II intron

Pre-mRNA intron

• A Group I intron
• B Group II intron
• C Pre-mRNA intron

Pre-mRNA splicing requires the aid of a multicomponent structure called the

spliceosome

Which of the following statements about splicing in eukaryotes is true?

Multiple choice question.

Both pre-mRNA splicing and self-splicing are very rare.

Both pre-mRNA splicing and self-splicing are widespread phenomena.

Pre-mRNA splicing is a widespread phenomenon, whereas self-splicing is relatively uncommon.

Self-splicing is a widespread phenomenon, whereas pre-mRNA splicing is relatively uncommon.

Pre-mRNA splicing is a widespread phenomenon, whereas self-splicing is relatively uncommon.

Splicing that does not require the aid of other catalysts is known as ____-splicing.

self

A small nuclear ribonucleoprotein (snRNP) consists of small ____ ____ and proteins.

nuclear RNA

Which of the following are self-splicing introns that occur in the rRNA genes of the protist Tetrahymena?

Multiple choice question.

Group II introns

Group I introns

Group III introns

Group I introns

For splicing of pre-mRNA in mammals, the spliceosome recognizes a branch site in the middle of the intron and two sites at the ends of the intron, called the _____ and _____ splice sites.

5'; 3'

The mechanism of self-splicing of group II introns is similar to that of group I introns. The main difference is that a 2'-OH group on a(n) ____ nucleotide within the intron begins the catalytic process.

adenine, A, or adenosine

The metalloribozyme of the spliceosome relies on ______ ions to catalyze removal of introns from ______.

Multiple choice question.

iron; precursor tRNA

iron; pre-mRNA

magnesium; pre-mRNA

magnesium; precursor rRNA

magnesium; pre-mRNA

What is a spliceosome?

Multiple choice question.

A multicomponent structure that removes introns found in pre-mRNA

Another term for the process of alternative splicing

A multicomponent structure that assists in the removal of group I and group II introns

A group of ribosomes that are bound simultaneously to the same mRNA

A multicomponent structure that removes introns found in pre-mRNA

Which of the following can account for different mature transcripts produced from the same pre-mRNA?

Multiple choice question.

5' capping

Self-splicing

Alternative splicing

3' polyadenylation

Reverse transcription

Alternative splicing

True or false: In complex eukaryotes, pre-mRNA splicing is much more common than self-splicing.

True

What are snRNPs?

Multiple choice question.

Components of RNA polymerase II

Proteins that facilitate DNA replication

Components of the spliceosome

Proteins that facilitate 5' capping

Components of the spliceosome

Alternative splicing allows an organism to ______.

Multiple choice question.

transcribe its genes more accurately

repair its genes more efficiently

carry fewer genes in its genome

carry more genes in its genome

carry fewer genes in its genome

Select all that apply

The removal of introns from mammalian pre-mRNA depends upon sequences located at which positions on the intron RNA?

Multiple select question.

adenosine site

guanosine binding site

5' splice site

3' splice site

Lariat formation site

branch site

5' splice site

3' splice site

branch site

The U6 subunit of the spliceosome is called a(n) ______ since its catalytic activity depends upon the presence of Mg²⁺ ions.

Multiple choice question.

capping enzyme

self-splicing enzyme

polyadenylating enzyme

alternative splicing enzyme

metalloribozyme

metalloribozyme

Exons that are always found in a mature mRNA that are likely to be required for the general structure and function of a protein are ____ exons.

constitutive

The phenomenon whereby different combinations of exons are joined to produce different mRNAs from the same transcript is called ____ ____ (or exon shuffling).

alternative splicing

______ often encodes a portion of a protein that only slightly changes the function of that protein.

Multiple choice question.

A self-splicing intron

A constitutive exon

An alternative intron

An alternative exon

An alternative exon

Select all that apply

In which ways do splicing factors regulate the ability of the spliceosome to choose splice sites?

Multiple select question.

change the mechanism to self-splicing

enhance the ability of the spliceosome to recognize specific splice sites

change the splicing recognition sequence at the intron-exon junctions

act as repressors to inhibit the ability of a spliceosome to recognize a splice site

enhance the ability of the spliceosome to recognize specific splice sites

act as repressors to inhibit the ability of a spliceosome to recognize a splice site

What is the biological advantage of alternative splicing?

Multiple choice question.

Multiple proteins can be derived from a single gene

Multiple pre-mRNAs can be derived from the same gene

Introns are removed more efficiently from the same mRNA

Multiple proteins can be derived from a single gene

Exon-skipping occurs when ______.

Multiple choice question.

an exon is present in a mature mRNA

RNA polymerase skips over an exon during transcription

an exon is not included in a mature mRNA

an intron is included in a mature mRNA

an exon is not included in a mature mRNA

An exon that is required for the general structure and function of a protein is likely to be a(n) ______.

Multiple choice question.

constitutive exon

self-splicing exon

alternative exon

constitutive exon

The capping of a mature mRNA is an event that involves the addition of ______ to its ______.

Multiple choice question.

about 100-200 adenines; 3' end

a 7-methylguanosine; 5' end

a 7-methylguanosine; 3' end

about 100-200 adenines; 5' end

a 7-methylguanosine; 5' end

A portion of an mRNA that is only found in some cell types is a(n) ____ exon.

alternative

Splicing factors can act as _ to inhibit the ability of the spliceosome to recognize a splice site or as _ to increase the ability of the spliceosome to recognize specific splice sites.

repressors; enhancers

The process by which an exon is not included in a mature mRNA is known as exon-

skipping

Select all that apply

The removal of introns from mammalian pre-mRNA depends upon sequences located at which positions on the intron RNA?

Multiple select question.

adenosine site

branch site

5' splice site

Lariat formation site

3' splice site

guanosine binding site

branch site

5' splice site

3' splice site

The addition of a 7-methylguanosine to the 5' end of a mature mRNA is a process known as

capping

The capping of a mature mRNA is a three-step process: (1) the enzyme RNA 5'-____ removes a phosphate; (2) the enzyme ____ attaches guanosine monophosphate (GMP) to the 5' end; and (3) the enzyme _____ attaches a methyl group to a nitrogen at position 7 in the guanine base.

triphosphatase

guanylyltransferase

methyltransferase

Select all that apply

Which of the following are functions of the 7-methylguanosine cap of eukaryotic mRNAs?

Multiple select question.

Efficient splicing of introns, particularly the most 5' intron

Recognition of the transcript by translation initiation factors

Synthesis of the polyA tail at the 3' end

Aggregation site for proteins involved in RNA editing

Exit of most mRNAs from the nucleus into the cytoplasm

Efficient splicing of introns, particularly the most 5' intron

Recognition of the transcript by translation initiation factors

Exit of most mRNAs from the nucleus into the cytoplasm

The processing that occurs at the 3' end of eukaryotic mRNAs is known as ______.

Multiple choice question.

polyadenylation

self-splicing

alternative splicing

capping

polyadenylation

Exon-skipping occurs when ______.

Multiple choice question.

an exon is not included in a mature mRNA

an intron is included in a mature mRNA

RNA polymerase skips over an exon during transcription

an exon is present in a mature mRNA

an exon is not included in a mature mRNA

This figure depicts the ______.

Multiple choice question.

3' splice site of the intron

5' splice site of the intron

5' capping signal sequence

3' polyadenylation signal sequence

3' polyadenylation signal sequence

Place the steps of mRNA capping in order, starting with the earliest on top.

Methyltransferase attaches a methyl group to the guanine base

RNA 5'-triphosphatase removes one of the three phosphates

Guanyltransferase attaches GMP to the 5' end

1. RNA 5'-triphosphatase

2. Guanyltransferase

3. Methyltransferase

In some cases, an mRNA molecule can be subjected to addition or deletion or conversion of bases, after transcription. This phenomenon is best described as RNA ______.

Multiple choice question.

splicing

modification

processing

editing

capping

editing

Multiple Choice Question

The 7-methylguanosine cap of eukaryotic mRNAs serves which of the following functions?

Multiple choice question.

Synthesis of the polyA tail at the 3' end

Recognition of the 5' end of the transcript by the translation machinery

Transport of mRNAs into the nucleus

Blocking the splicing machinery which may render the mRNA nonfunctional

Recognition of the 5' end of the transcript by the translation machinery

What is produced by this reaction?

Multiple choice question.

Uracil

Thymine

Guanine

Inosine

Uracil

The enzymatic addition of about 250 adenine nucleotides to the mRNA after it is transcribed is a process called

polyadenylation

Which one is not a characteristic of bacterial transcription?

Multiple choice question.

Termination can be rho-dependent or rho-independent

mRNA can be modified by RNA editing

Presence of a single RNA polymerase

mRNA can be degraded after addition of a 3' polyA tail

Promoter consists of a -35 and -10 sequence

mRNA can be modified by RNA editing

At the ribosome, tRNA anticodons recognize mRNA codons to produce a protein through the process of ______.

Multiple choice question.

translation

duplication

replication

transcription

translation

The polyadenylation signal sequence in eukaryotic mRNA is ______.

Multiple choice question.

5' AAUAAA 3'

5' AAAUUU 3'

5' TATAAAA 3'

5' TTGACAA 3'

5' AAUAAA 3'

When a protein-encoding gene is transcribed, the product is called _____ RNA.

messenger or m

The process by which the nucleotide sequence of a mRNA molecule is changed after it has been transcribed is called ____ ____.

RNA editing

Providing the information to produce suitable amounts of a protein appropriate to a specific cell type is the function of the ____ material.

genetic

The product of this reaction is

hypoxanthine or inosine

To explain why patients had a buildup of the urine-darkening metabolite homogentisic acid, Archibald Garrod proposed that they were lacking ______.

Multiple choice question.

mitochondria

an enzyme that would metabolize homogentisic acid

receptors for homogentisic acid

ribosomes to make metabolic enzymes

an enzyme that would metabolize homogentisic acid

Select all that apply

Which of the following are features of transcription in eukaryotes only?

Multiple select question.

Presence of three types of RNA polymerases

Mediator controls the switch to the elongation phase

Termination occurs according to the allosteric or torpedo model

Addition of 7-methylguanosine cap

The promoter consists of a -35 and a -10 sequence

Presence of three types of RNA polymerases

Mediator controls the switch to the elongation phase

Termination occurs according to the allosteric or torpedo model

Addition of 7-methylguanosine cap

The synthesis of a protein using the sequence of codons in a messenger RNA is called

translation

Garrod was the first to suggest that there is a relationship between ____ and the production of proteins.

genes

Note: Garrod's proposition, attributing a defective enzyme to a defective gene, was the first ever to suggest a direct link between genes and proteins.

Which type of RNA is transcribed from a protein-encoding gene?

Multiple choice question.

messenger RNA

transfer RNA

ribosomal RNA

messenger RNA

In which organism did Beadle and Tatum conduct their experiments?

Multiple choice question.

Escherichia coli

Neurospora crassa

Mus musculus

Saccharomyces cerevisiae

Neurospora crassa

Note: Beadle and Tatum worked with a simple organism: common bread mold, or Neurospora crassa. Using Neurospora, they were able to show a clear connection between genes and metabolic enzymes.

Select all that apply

Which represent the function(s) of the genetic material?

Multiple select question.

Ensuring that a protein is produced at the proper time in the cycle of the cell or life cycle of the organism.

Carrying out metabolic reactions appropriate to a specific cell type.

Ensuring that a protein is produced in sufficient amounts for effective cellular functions.

Coordinating the assembly of cellular organelles.

Encoding the production of a protein in a specific cell type.

Ensuring that a protein is produced at the proper time in the cycle of the cell or life cycle of the organism.

Ensuring that a protein is produced in sufficient amounts for effective cellular functions.

Encoding the production of a protein in a specific cell type.

In experiments where Beadle and Tatum were able to determine the steps in a biochemical pathway, they concluded that the synthesis of a single enzyme was controlled by a ______

Multiple choice question.

Second

single chromosome

single gene

single enzyme

single gene

Archibald Garrod proposed that the buildup of homogentisic acid leading to the symptoms of alkaptonuria resulted from a missing

enzyme

Select all that apply

Select ways in which the one-gene/one-enzyme hypothesis had to be modified from its original form.

Multiple select question.

All proteins, including enzymes as well as other types of proteins, are encoded by genes.

Some genes encode functional RNA molecules rather than polypeptides.

Alternative splicing and RNA editing can produce more than one polypeptide from a single gene.

One gene encodes one protein, which may be made up of many different polypeptide chains.

All proteins, including enzymes as well as other types of proteins, are encoded by genes.

Some genes encode functional RNA molecules rather than polypeptides.

Alternative splicing and RNA editing can produce more than one polypeptide from a single gene.

The bacterial RNA polymerase core enzyme is composed of five different polypeptide chains. The number of genes needed to code for this enzyme is ____. Assume alternative splicing is not used here.

5

Which scientist(s) was/were the first to propose a relationship between genes and the production of proteins?

Multiple choice question.

Garrod

Beadle & Tatum

Nirenberg & Matthaei

Watson & Crick

Garrod

Beadle and Tatum designed experiments to test how ____ required for the biosynthesis of methionine are controlled by genes.

enzymes

A protein can be made of more than one

polypeptide

Note: This forms the primary structure of a long polypeptide chain. Proteins are made up of one or several polypeptides that have interacted together to form the final, stable, working conformation. Amino acids can either be α-amino acids are β-amino acids.

In experiments where Beadle and Tatum were able to deduce the steps in a biochemical pathway, they concluded that a single gene controlled the synthesis of a ______ ______.

Multiple choice question.

single carbohydrate

single gene

single chromosome

single enzyme

Second

single enzyme

Which one is a product of transcription that does not encode a protein, such as a transfer RNA or a ribosomal RNA?

Multiple choice question.

functional RNA molecule

translational RNA molecule

non-genic sequence

functional RNA molecule

Select all that apply

Select all types of new information that led to modification of the original one-gene/one-enzyme hypothesis.

Multiple select question.

One gene can be used to make more than one polypeptide.

Many genes can affect the same phenotypic trait.

Some proteins are made of more than one type of polypeptide.

Enzymes are not the only protein products of genes.

One gene can affect more than one phenotypic trait.

Some genes code for functional RNA products.

One gene can be used to make more than one polypeptide.

Some proteins are made of more than one type of polypeptide.

Enzymes are not the only protein products of genes.

Some genes code for functional RNA products.

Select all that apply

One stretch of genomic DNA can lead to the production of more than one polypeptide due to ______.

Multiple select question.

alternative splicing of introns

RNA editing

transcription of different portions of the DNA sequence

translation of different portions of the mRNA

alternative splicing of introns

RNA editing

Suppose there is an enzyme that is made of two different polypeptide chains. How many genes are needed to code for this enzyme? Assume alternative splicing is not used here.

Multiple choice question.

One gene because there is only one enzyme.

Four genes, because there are active and inactive forms of each polypeptide chain.

Two genes, one for each polypeptide chain.

Two genes, one for each polypeptide chain.

Which amino acid will be carried by a tRNA with the following anticodon: 3'-GUA-5'?

Multiple choice question.

Tyrosine

Valine

Histidine

Methionine

Histidine

A set of three-letter combinations of nucleotides called codons, each of which corresponds to a specific amino acid, represents the

genetic code

Which of the following is correct?

Multiple choice question.

A polypeptide can be made of more than one protein.

All polypeptides are only made of one protein.

A protein can be made of more than one polypeptide.

All proteins are only made of one polypeptide.

A protein can be made of more than one polypeptide.

If a gene's transcript is not used to build a polypeptide, it may encode a ____ ____ molecule.

functional RNA

Alternative splicing and RNA editing are mechanisms that allow ______.

Multiple choice question.

several genes to produce one polypeptide

several genes to produce the same mRNA

several different mRNAs to produce the same polypeptide

one gene to produce several different polypeptides

one gene to produce several different polypeptides

If tryptophan is amino acid #67 in a particular protein, what is the anticodon of the transfer RNA that delivered tryptophan to this location?

Multiple choice question.

3'-ACC-5'

5'-GGU-3'

5'-UGG-3'

3'-CCA-5'

3'-ACC-5'

Arranging the four RNA nucleotides A, G, C and U in groups of three with all possible combinations leads to a set of codons called the ______.

Multiple choice question.

transfer RNA sequence

genetic code

gene sequence

ribosomal RNA sequence

amino acid sequence

genetic code

Which type of codon would lead to the placement of a specific amino acid such as leucine into the polypeptide sequence?

Multiple choice question.

Nonsense codon

Start codon

Sense codon

Stop codon

Sense codon

Select all that apply

What other names refer to stop codons?

Multiple select question.

Start codons

Sense codons

Termination codons

Nonsense codons

Termination codons

Nonsense codons

A series of three nucleotide bases that specifies the placement of the amino acid methionine at the beginning of a polypeptide chain is a ______ codon.

Multiple choice question.

nonsense

synonymous

start

stop

start

A series of three nucleotide bases that specifies the insertion of a particular amino acid into a polypeptide chain is a ____ ____.

sense codon

A series of three nucleotide bases that signals the end of a polypeptide chain is a(n) ______ codon.

Multiple choice question.

synonymous

start

sense

stop

antisense

stop

The codon AUG can act as a start codon or as a _____ codon to specify the placement of additional methionines in a polypeptide.

Multiple choice question.

synonymous codon

stop codon

nonsense codon

termination codon

sense codon

sense codon

To bring a specific amino acid into its location on a polypeptide chain, which sequence on transfer RNA must bind to messenger RNA?

Multiple choice question.

5' sequence

Anticodon

Codon

3' sequence

Anticodon

A sequence of bases that begins with the start codon and continues to the end of the coding sequence by reading the bases in groups of three is called the ____ ____.

genetic code

several different mRNAs to produce the same polypeptide

several genes to produce one polypeptide

several genes to produce the same mRNA

one gene to produce several different polypeptides

one gene to produce several different polypeptides

The genetic code is described as universal, yet exceptions to the rules exist. How widespread are these exceptions?

Multiple choice question.

At least 20 codon differences exist for eukaryotes such as yeast and ciliated protozoans

The genetic code of a mitochondrion has completely unique codons

A few codon differences exist, particularly within mitochondria

A few codon differences exist, particularly within mitochondria

An AUG codon, which specifies the amino acid methionine and is often the first codon that begins a polypeptide sequence, is called a(n) codon.

start

Selenocysteine and pyrrolysine are encoded by codons that usually function as ______.

Multiple choice question.

cysteine and lysine codons

anticodons

start codons

stop codons

stop codons

The signal for termination of translation is called a(n) ____ codon.

stop, nonsense, termination, terminator, or terminal

Which type of bond is formed between the carboxyl group of one amino acid and the amino group of the next amino acid?

Multiple choice question.

ionic bond

phosphodiester bond

peptide bond

hydrogen bond

peptide bond

A series of three nucleotides in transfer RNA that is complementary to a codon in messenger RNA is called a(n)

anticodon

Suppose methionine is located at the amino-terminus of a specific protein. The codon for methionine would be located closest to which portion of the corresponding mRNA?

Multiple choice question.

The 5' end of the mRNA

The 3' end of the mRNA.

The middle of the mRNA

The 5' end of the mRNA

Beginning with the start codon and reading the following bases in groups of three determines the ______.

Multiple choice question.

reading frame

promoter sequence

transcript

untranslated region

reading frame

Where is the first amino acid in a polypeptide chain is located?

Multiple choice question.

amino-terminus

R-terminus

central-terminus

carboxyl-terminus

amino-terminus

UGA is a stop codon for messenger RNAs translated in the cytoplasm of eukaryotic cells but is a codon for tryptophan in that cell’s mitochondria. What is the explanation for this phenomenon?

Multiple choice question.

There are no stop codons used during protein synthesis in mitochondria

None of the codons used in mitochondria are similar to the codons used by the surrounding cell

Codons used in mitochondria show a few exceptions to the universal genetic code

Proteins made in the surrounding cell do not contain tryptophan

Codons used in mitochondria show a few exceptions to the universal genetic code

The amino acids that are sometimes referred to as the twenty-first and twenty-second amino acids are called ____ and ____.

selenocysteine or Sec

pyrrolysine or Pyl

Where is the last amino acid in a polypeptide chain is located?

Multiple choice question.

amino-terminus

R-terminus

central-terminus

carboxyl-terminus

carboxyl-terminus

What is the name for the type of bond that joins the amino acids as shown by the arrows in the diagram?

Multiple choice question.

Peptide bond

Ionic bond

Hydrogen bond

Phosphodiester bond

Peptide bond

What is the name for the chemical group that is unique for each of the 20 amino acids?

Multiple choice question.

R group

carboxylic acid group

central carbon

amino group

R group

The codon for the amino acid found at the carboxyl-terminus of a polypeptide is located closest to the ____ end of the corresponding mRNA.

3'

When a polypeptide is synthesized, the first amino acid to be put in place is located at the ______-______.

Multiple choice question.

carboxyl- or C-terminus

amino- or N-terminus

amino- or N-terminus

Which type of R group is consistent with an amino acid that is found in the interior of a folded protein?

Multiple choice question.

Hydrophilic

Neither hydrophobic nor hydrophilic

Hydrophobic

Both hydrophobic and hydrophilic

Hydrophobic

The position on the polypeptide chain indicated by the arrow in the diagram is the ______.

Multiple choice question.

amino-terminus

3'-end

carboxyl-terminus

stop codon

start codon

carboxyl-terminus

The sequence of amino acids that results from gene transcription and mRNA translation represents which structure of the protein?

Multiple choice question.

Secondary structure

Primary structure

Tertiary structure

Quaternary structure

Primary structure

Which group gives an amino acid its unique chemical properties?

Multiple choice question.

amino group

central carbon

R group

carboxylic acid group

R group

What dictates the pattern of folding of a protein?

Multiple choice question.

The number of polypeptide chains that associate with each other

The number of ionic bonds occurring in the secondary structure

The chemical features of the R groups in the primary sequence

The chemical features of the R groups in the primary sequence

A protein that assists with the proper folding of other polypeptides is a(n)

chaperone

Where is the first amino acid in a polypeptide chain is located?

Multiple choice question.

carboxyl-terminus

R-terminus

amino-terminus

central-terminus

amino-terminus

Which type of R group is consistent with an amino acid that is found on the exterior of a folded protein?

Multiple choice question.

Both hydrophilic and hydrophobic

Hydrophobic

Neither hydrophilic nor hydrophobic

Hydrophilic

Hydrophilic

The initial folding of a polypeptide into a regular repeating shape represents its ____ structure.

secondary

The consecutive order of amino acids in a polypeptide chain represents its ____ structure.

primary

The folded-three dimensional conformation of a polypeptide represents its ____ structure.

tertiary

Suppose you are comparing two cellular proteins that have different three-dimensional shapes. What is the determining factor that led to those differences?

Multiple choice question.

The two proteins were synthesized at different speeds.

The two proteins have the same R groups, but different N groups.

The two proteins have different amino acid sequences.

The two proteins were produced by different ribosomes.

Correct Answer

The two proteins have different amino acid sequences.

The two proteins have different amino acid sequences.

Proper folding of some polypeptides requires the assistance of a(n) ______.

Multiple choice question.

ribosome

enzyme

transfer RNA

chaperone

chaperone

The oxygen-carrying molecule hemoglobin is an association of four polypeptides, two called α-hemoglobin and two called β-hemoglobin. The level of protein structure demonstrated by hemoglobin is ______ structure.

Multiple choice question.

quaternary

primary

secondary

tertiary

quaternary

When a polypeptide is synthesized, the first amino acid to be put in place is located at the ______-______.

Multiple choice question.

amino- or N-terminus

carboxyl- or C-terminus

amino- or N-terminus

Which level of protein structure is represented by the association of multiple polypeptide subunits?

Multiple choice question.

Quaternary structure

Primary structure

Tertiary structure

Secondary structure

Quaternary structure

The protein structure stabilized by the formation of hydrogen bonds between atoms found in the polypeptide backbone is ______ structure.

Multiple choice question.

quaternary

primary

tertiary

secondary

secondary

The folding of α helical regions and beta-sheet regions relative to each other leads to formation of a polypeptide's ______ structure.

Multiple choice question.

primary

tertiary

quaternary

secondary

tertiary

Cells of the pancreas secrete the hormone insulin to assist with glucose uptake while neurons release neurotransmitters to conduct nerve signals. The difference in products released by these two types of cells depends on differences in ______.

Multiple choice question.

DNA content between the two types of cells

the types of proteins produced within each cell

the genetic code between the two types of cells

differences in the structure of ribosomes found in each type of cell

the types of proteins produced within each cell

To determine the codons of the genetic code, scientists added mRNA and amino acids to an extract from bacterial cells containing ribosomes and tRNAs that was called a ____-____ ____ system.

cell-free translation

For a protein, an association of two or more polypeptide chains represents its ____ structure.

quaternary

Note: Quaternary structure exists in proteins consisting of two or more identical or different polypeptide chains (subunits). These proteins are called oligomers because they have two or more subunits. The quaternary structure describes the manner in which subunits are arranged in the native protein.

Select all that apply

If a cell-free translation were carried out with synthetic mRNAs produced from a mixture of 25% G and 75% A, which amino acids would be incorporated into the resulting polypeptides?

Multiple select question.

Glutamine

Serine

Glutamic acid

Glycine

Lysine

Arginine

Glutamic acid

Glycine

Lysine

Arginine

For a protein with quaternary structure, the individual polypeptides are called ____ of the protein.

subunits

If synthetic mRNAs are made with a mixture of 60% C and 40% U, what is the predicted percentage of proline among the amino acids in the polypeptides produced from these synthetic mRNAs?

Multiple choice question.

21.6%

24%

36%

14.4%

16%

36%

36% Explanation – Since, the mixture for synthetic mRNA contains 60% C and 40% U. Thus, Frequency of C in synthetic mRNA will be = 60/100 = 0.6 Frequency of U in synthetic mRNA will be = 40/100 = 0.4 Frequency of different possible combinations

Suppose a mixture of 40% C and 60% A was used to produce synthetic mRNAs, and the percentage of asparagine among the amino acids in the resulting polypeptides was 14.4%. This suggests that the codon for asparagine has ______.

Multiple choice question.

two Cs and one A

three Cs

two As and one C

three As

two As and one C

Properties such as cell shape and organization and cellular movement depend upon the direct action of which type of cellular component?

Multiple choice question.

Carbohydrates

Lipids

Nucleic Acids

Proteins

Proteins

To decipher the genetic code, scientists were able to synthesize radioactively-labeled polypeptides from synthetic messenger RNAs in a ______ system.

Multiple choice question.

ribosome-free translation

cell-free translation

tRNA-free translation

cell-free transcription

cell-free translation

In experiments designed to "crack" the genetic code, a cell-free translation system was used to produce ______ when ______ were added.

Multiple choice question.

polypeptides; mRNA and amino acids

messenger RNA; ribonucleotides

ribosomes; RNA and proteins

tRNAs; amino acids

polypeptides; mRNA and amino acids

Select all that apply

If a cell-free translation were carried out with synthetic mRNAs produced from a mixture of 25% A and 75% C, which amino acids would be incorporated into the resulting polypeptides?

Multiple select question.

Asparagine

Threonine

Glutamic acid

Histidine

Proline

Aspartic acid

Lysine

Glutamine

Asparagine

Threonine

Histidine

Proline

Lysine

Glutamine

Select all that apply

Which of the following were used in the efforts to decipher the genetic code?

Multiple select question.

Triplet-binding assays to determine which transfer RNAs bind to specific codons

Cell-free translation experiments using synthetic messenger RNAs

In vitro transcription assays to show which types of mRNA are produced

Cell-free translation experiments using RNA copolymers with repeating patterns of nucleotides

Triplet-binding assays to determine which transfer RNAs bind to specific codons

Cell-free translation experiments using synthetic messenger RNAs

Cell-free translation experiments using RNA copolymers with repeating patterns of nucleotides

If synthetic mRNAs are made with a mixture of 60% C and 40% U, what is the predicted percentage of phenylalanine among the amino acids in the polypeptides produced from these synthetic mRNAs?

Multiple choice question.

9.6%

6.4%

24%

36%

16%

16%

Suppose a mixture of 40% C and 60% A was used to produce synthetic mRNAs, and the percentage of histidine among the amino acids in the resulting polypeptides was 9.6%. This suggests that the codon for histidine has ______.

Multiple choice question.

two Cs and one A

three As

two As and one C

three Cs

two Cs and one A

To decipher the genetic code, a cell-free translation system containing ribosomes, tRNAs, enzymes and radioactive amino acids was used to ______.

Multiple choice question.

synthesize prokaryotic DNA from RNA

directly observe codon-anticodon binding

synthesize radioactively-labeled polypeptides from synthetic messenger RNAs

synthesize messenger RNAs from prokaryotic DNA

synthesize radioactively-labeled polypeptides in the absence of mRNA

synthesize radioactively-labeled polypeptides from synthetic messenger RNAs

To account for the involvement of RNA molecules for incorporating amino acids into a protein chain, Francis Crick proposed the ______ hypothesis.

Multiple choice question.

genetic code

wobble

base-pairing

adaptor

adaptor

Which amino acid is carried by a transfer RNA with an anticodon sequence of 3'-GCA-5'?

Multiple choice question.

Cysteine

Alanine

Arginine

Threonine

Arginine

In addition to cell-free translation experiments with mixtures of synthetic RNAs, efforts to decipher the genetic code included ______.

Multiple choice question.

cell-free translation of copolymers and triplet-binding assays

transcription assays and cell-free translation of copolymers

DNA-RNA binding assays and triplet-binding assays

cell-free translation of copolymers and triplet-binding assays

Which nucleotide in a tRNA anticodon would bind to the A nucleotide in an mRNA codon?

Multiple choice question.

G

U

C

T

A

U

Which of the following represent common structural features of transfer RNA molecules?

Multiple select question.

Anticodon sequence

Codon sequence to specify which amino acid will bind

Amino acid acceptor stem with a 3' single-stranded region

A small number of variable sites

Three stem-loops

Anticodon sequence

Amino acid acceptor stem with a 3' single-stranded region

A small number of variable sites

Three stem-loops

Suppose a mixture of 40% C and 60% A was used to produce synthetic mRNAs, and the percentage of asparagine among the amino acids in the resulting polypeptides was 14.4%. This suggests that the codon for asparagine has ______.

Multiple choice question.

two Cs and one A

two As and one C

three Cs

three As

two As and one C

Francis Crick proposed that certain types of RNA molecules were involved in the incorporation of amino acids into a polypeptide chain in the ____ hypothesis.

adaptor

The single-stranded region at the 3' end of a transfer RNA is the location where a(n) ______ becomes attached.

Multiple choice question.

carboxyl group

hydroxyl group

poly-A tail

7-methyl guanosine cap

amino acid

amino acid

Which amino acid is carried by a transfer RNA with an anticodon sequence of 3'-CGA-5'?

Multiple choice question.

Serine

Alanine

Arginine

Cysteine

Alanine

Which nucleotide in a tRNA anticodon would bind to the U nucleotide in an mRNA codon?

Multiple choice question.

G

C

A

T

U

A

The function of an aminoacyl-tRNA synthetase enzyme is to catalyze the ______.

Multiple choice question.

synthesis of tRNA

binding of a tRNA anticodon to a mRNA codon

attachment of an amino acid to its appropriate tRNA

addition of amino acids to a growing polypeptide chain

addition of a single-stranded sequence to the 3' end of the tRNA

attachment of an amino acid to its appropriate tRNA

Which type of RNA is shown in the figure?

Multiple choice question.

Messenger RNA

Transfer RNA

Ribosomal RNA

Transfer RNA

Select all that apply

Which of the following must bind to an aminoacyl-tRNA synthetase enzyme in order to charge a transfer RNA?

Multiple select question.

ATP

An mRNA codon

A specific amino acid

A specific transfer RNA

Pyrophosphate

A ribosome

ATP

A specific amino acid

A specific transfer RNA

The location on a transfer RNA where an amino acid becomes attached is the ______.

Multiple choice question.

5' end with a double-stranded region

variable site

acceptor stem with a 3' single-stranded region

stem-loop structure

anticodon

acceptor stem with a 3' single-stranded region

Which enzyme catalyzes the attachment of a specific amino acid to the correct tRNA?

Multiple choice question.

Transfer RNA nucleotidyltransferase

Amino acid transferase

Aminoacyl-tRNA synthetase

Peptidyl transferase

RNA polymerase

Aminoacyl-tRNA synthetase

A transfer RNA that has an amino acid attached to its 3' end is called a(n) ____ ____.

aminoacyl tRNA

In order to charge a tRNA, ATP, a specific transfer RNA and a specific amino acid all bind to which enzyme?

Multiple choice question.

RNA polymerase

Amino acid synthetase

ATP synthase

Aminoacyl-tRNA synthetase

Peptidyl-transferase

Aminoacyl-tRNA synthetase

Select all that apply

Chemically-modified bases in transfer RNA molecules can affect ______.

Multiple select question.

codon-anticodon recognition

peptide chain termination

translation rate

recognition of tRNAs by aminoacyl-tRNA synthetases

transcription rate

codon-anticodon recognition

translation rate

recognition of tRNAs by aminoacyl-tRNA synthetases

Codons UUC and UUU lead to the placement of phenylalanine at a specific position in the protein chain. This type of mismatch in codon-anticodon binding that can occur at the third base of the codon is called

wobble

The single-stranded region at the 3' end of a transfer RNA is the location where a(n) ______ becomes attached.

Multiple choice question.

7-methyl guanosine cap

amino acid

hydroxyl group

poly-A tail

carboxyl group

amino acid

The complex of rRNA and protein that acts as the site of translation is the

ribosome

Note: As previously mentioned, ribosomes are the specialized cellular structures in which translation takes place. This means that ribosomes are the sites at which the genetic code is actually read by a cell. Ribosomes are themselves composed of a complex of proteins and specialized RNA molecules called ribosomal RNA (rRNA).

Both eukaryotic and prokaryotic cells have ribosomes in the

cytosol, cytoplasm, or cytosolic

An aminoacyl-tRNA is a transfer RNA ______.

Multiple choice question.

that is ready to pick up an amino acid

with an amino acid attached to its 3' end

that has delivered its amino acid to a growing peptide chain

with an amino acid attached to its 5' end

with an amino acid attached to its 3' end

Select all that apply

In eukaryotic cells, where can ribosomes be found?

Multiple select question.

In chloroplasts

Embedded in the plasma membrane

In mitochondria

In the Golgi apparatus

In the cytosol

In chloroplasts

In mitochondria

In the cytosol

Which positions of tRNA molecules contain the largest variety of modified nucleotides?

Multiple choice question.

19 and 60

1 and 70

34 and 37

12 and 47

34 and 37

According to the wobble rules, which base of the codon can be mismatched with an anticodon base on the tRNA?

Multiple choice question.

Third base of the codon

Any of the three bases of the codon

First base of the codon

Second base of the codon

None of the three bases of the codon

Third base of the codon

Select all that apply

Which components are assembled into the subunits of a ribosome?

Multiple select question.

Transfer RNA

Ribosomal RNA

Messenger RNA

Ribosomal proteins

Ribosomal RNA

Ribosomal proteins

Translation takes place on a structure called the

ribosome

Note: Translation occurs in a structure called the ribosome, which is a factory for the synthesis of proteins. The ribosome has a small and a large subunit and is a complex molecule composed of several ribosomal RNA molecules and a number of proteins.

In eukaryotic cells, the ______ is the site of ribosomal subunit assembly, using ______ from the cytosol and ______ from the nucleus.

Multiple choice question.

nucleolus, rRNA, proteins

cytosol, rRNA, proteins

nucleolus, proteins, rRNA

nucleolus, proteins, mRNA

cytosol, proteins, rRNA

nucleolus, proteins, rRNA

In which cellular location would ribosomes be found for both prokaryotic and eukaryotic cells?

Multiple choice question.

Mitochondria

Chloroplasts

Mitochondria and chloroplasts

Cytosol, mitochondria and chloroplasts

Cytosol

Cytosol

A plant cell will have ribosomes in its ______.

Multiple choice question.

cytosol only

cytosol and chloroplasts only

cytosol, mitochondria and chloroplasts

mitochondria only

chloroplasts only

cytosol, mitochondria and chloroplasts

A polyribosome is ______.

Multiple choice question.

many ribosomes bound to transfer RNAs

many messenger RNAs bound to the same two ribosomal subunits

a messenger RNA transcript that has many bound ribosomes in the act of translation

a ribosome with three or more subunits

a messenger RNA bound to a ribosome with three or more subunits

a messenger RNA transcript that has many bound ribosomes in the act of translation

Select all that apply

Chemically-modified bases in transfer RNA molecules can affect ______.

Multiple select question.

translation rate

codon-anticodon recognition

peptide chain termination

recognition of tRNAs by aminoacyl-tRNA synthetases

transcription rate

translation rate

codon-anticodon recognition

recognition of tRNAs by aminoacyl-tRNA synthetases

Each ribosomal subunit is assembled from ribosomal RNA and many different

proteins

Note: Each subunit consists of one or more ribosomal RNA (rRNA) molecules and many ribosomal proteins (RPs or r-proteins). The ribosomes and associated molecules are also known as the translational apparatus.

For bacterial translation, the mRNA is found within a ______.

Multiple choice question.

channel in the small ribosomal subunit, and the polypeptide exits through a channel in the large ribosomal subunit

channel in the large ribosomal subunit, and the polypeptide is located within a space between the ribosomal subunits

space between the ribosomal subunits, and the polypeptide exits through a channel within the large ribosomal subunit

space between the ribosomal subunits, and the polypeptide exits through a channel within the large ribosomal subunit

Proteins produced in the cytoplasm and rRNA made in the nucleus are joined to assemble ribosomal subunits in the ____ of a eukaryotic cell.

nucleolus

Select all that apply

Which represent specific sites on the ribosome where transfer RNAs bind?

Multiple select question.

G=Growing polypeptide site

N=New amino acid site

P=peptidyl site

A=aminoacyl site

E=exit site

P=peptidyl site

A=aminoacyl site

E=exit site

The combination of a messenger RNA and many bound ribosomes in the process of translation is called a(n)

polyribosome

Which description matches each stage of translation?

Initiation

Elongation

Termination

A complex forms between the ribosomal subunits, one mRNA molecule and the first tRNA molecule.

Amino acids are linked together in the order designated by the codons.

The newly produced polypeptide is released from the ribosome.

• Initiation A complex forms between the ribosomal subunits, one mRNA molecule and the first tRNA molecule.
• Elongation Amino acids are linked together in the order designated by the codons.
• Termination The newly produced polypeptide is released from the ribosome.

In prokaryotic cells, a transfer RNA carrying N-formylmethionine recognizes the ______ and is the first tRNA to bind to the ribosomal subunits, so it is called the initiator tRNA.

Multiple choice question.

stop codon

start codon

promoter

operon

exon

start codon

During bacterial translation, which component is found in a space between the 30S and 50S ribosomal subunits?

Multiple choice question.

Messenger RNA

Ribosomal proteins

The polypeptide as it is synthesized

Transfer RNA

Messenger RNA

Select all that apply

In the first step of initiation complex formation, which factors bind to the small ribosomal subunit to prevent it from associating with the large ribosomal subunit?

Multiple select question.

Peptidyl-transferase

tRNA^fMet

IF3

IF1

IF2

IF3

IF1

Which site on the ribosome matches each of the functions listed?

A site

P site

E site

Site where an uncharged tRNA leaves the ribosome

Site of aminoacyl-tRNA binding

Site that contains a tRNA with an attached peptide

• A site Site of aminoacyl-tRNA binding
• P site Site that contains a tRNA with an attached peptide
• E site Site where an uncharged tRNA leaves the ribosome

In which cellular location would ribosomes be found for both prokaryotic and eukaryotic cells?

Multiple choice question.

Mitochondria and chloroplasts

Chloroplasts

Cytosol, mitochondria and chloroplasts

Cytosol

Mitochondria

Cytosol

Translation is divided into three stages: the first is ____, the next is ____, and the last is ____.

Blank 1: initiation

Blank 2: elongation

Blank 3: termination

In ______ cells, the initiator tRNA is carrying the amino acid N-formylmethionine.

Multiple choice question.

eukaryotic

prokaryotic

prokaryotic

What is the role of initiation factors IF1 and IF3?

Multiple choice question.

Promote the formation of the peptide bond

Promote the binding of the first transfer RNA to messenger RNA

Prevent messenger RNA from binding to the small ribosomal subunit

Promote messenger RNA binding to the ribosome

Prevent the small ribosomal subunit from associating with the large ribosomal subunit

Prevent the small ribosomal subunit from associating with the large ribosomal subunit

A 9-nucleotide sequence in prokaryotic mRNA that facilitates binding to the small ribosomal subunit is the ___-____ sequence.

Shine-Dalgarno

In forming the initiation complex, the factor that promotes the binding of the first tRNA to mRNA already bound to the 30S subunit is ______.

Multiple choice question.

Peptidyl transferase

Termination factor

IF3

IF2

IF1

IF2

Which description matches each stage of translation?

Initiation

Elongation

Termination

The newly produced polypeptide is released from the ribosome.

A complex forms between the ribosomal subunits, one mRNA molecule and the first tRNA molecule.

Amino acids are linked together in the order designated by the codons.

• Initiation A complex forms between the ribosomal subunits, one mRNA molecule and the first tRNA molecule.
• Elongation Amino acids are linked together in the order designated by the codons.
• Termination The newly produced polypeptide is released from the ribosome.

In prokaryotic cells, a transfer RNA carrying N-formylmethionine recognizes the ______ and is the first tRNA to bind to the ribosomal subunits, so it is called the initiator tRNA.

Multiple choice question.

operon

start codon

stop codon

promoter

exon

start codon

In prokaryotic cells, formation of the initiation complex requires the binding of tRNA^fMet to the ____ site of the ribosome.

P

The Shine-Dalgarno sequence facilitates the binding of ______.

Multiple choice question.

mRNA to the large ribosomal subunit

the second tRNA to the A site of the ribosome

mRNA to the small ribosomal subunit

the first tRNA to the P site of the ribosome

mRNA to the small ribosomal subunit

What is the name for each of the ribosomal sites, labeled as X, Y and Z on the accompanying figure?

X

Y

Z

E site

A site

P site

• X E site
• Y P site
• Z A site

At the end of translation, dissociation of the small and large ribosomal subunits in prokaryotes requires the binding of ____ to the ribosome.

IF1

In the formation of the initiation complex, binding of the first tRNA to the mRNA is promoted by the factor called

IF2

Select all that apply

For translation in vertebrates and vascular plants, the AUG used as the start codon requires specific bases in the surrounding sequences, including ______.

• a guanine at position +4
• a purine at position -3, preferably adenine

To which site does the transfer RNA carrying N-formylmethionine (tRNA^fMet) bind when forming the initiation complex in prokaryotic cells?

P site

The stage of translation in which amino acids are added one at a time to a growing polypeptide chain is called

elongation

In prokaryotic cells, which factor must bind to the ribosome to cause the dissociation of the small and large ribosomal subunits at the end of translation?

IF1

Which factor hydrolyzes GTP to provide energy for translocation in bacterial translation?

Multiple choice question.

Peptidyl transferaase

EF-Tu

EF-G

EF-Ts

EF-G

For translation in vertebrates and vascular plants, the AUG chosen as the start codon will be ______.

Multiple choice question.

surrounded by specific bases as defined by Kozak's rules

the AUG closest to the 3' end of the mRNA

the AUG closest to the 5' end of the mRNA

the AUG closest to the Shine-Dalgarno sequence

surrounded by specific bases as defined by Kozak's rules

To begin each round of elongation during translation, the tRNA carrying the next amino acid to be added to the polypeptide chain binds to the ____ site of the ribosome.

A or aminoacyl

The order in which amino acids are added to a polypeptide chain is determined by hydrogen bonding between each codon and the ______ of the tRNA carrying the amino acid.

Multiple choice question.

5' end

stem-loop structures

variable bases

anticodon

acceptor stem

anticodon

Amino acids are added sequentially to a growing polypeptide chain during ______.

Multiple choice question.

elongation

termination

initiation

elongation

What provides the energy for binding of the next tRNA to the A site during elongation in prokaryotic cells?

Multiple choice question.

EF-Tu hydrolyzing GTP

EF-G hydrolyzing GTP

EF-Tu hydrolyzing ATP

EF-Ts hydrolyzing GTP

EF-Tu hydrolyzing GTP

In prokaryotic translation, what provides the energy for translocation?

Multiple choice question.

EF-G hydrolyzing GTP

EF-Ts hydrolyzing GTP

EF-Tu hydrolyzing GTP

EF-G hydrolyzing ATP

EF-G hydrolyzing GTP

The 16S rRNA of the ribosome will prevent elongation until a mispaired tRNA is released from the A site. This process is termed the ____ function of the ribosome, and is important in maintaining high fidelity in translation.

decoding

To begin each round of elongation during translation, a tRNA carrying the next amino acid to be added to the polypeptide binds to which of the following?

Multiple choice question.

Shine-Dalgarno sequence

A site on the ribosome

P site on the ribosome

E site on the ribosome

A site on the ribosome

During elongation, the ______ of the incoming tRNA binds to the ______ of the mRNA.

Multiple choice question.

anticodon; codon

codon; amino acid

elongation factor; initiation factor

amino acid; codon

codon; anticodon

anticodon; codon

During elongation, the enzyme that catalyzes the transfer of the polypeptide in the P site to the amino acid in the A site is ______.

Multiple choice question.

aminoacyl tRNA synthetase

RNA polymerase

peptidyl transferase

polypeptide synthetase

peptidyl transferase

The movement of the ribosome to the next codon that occurs after the peptidyl transfer reaction is called ______.

Multiple choice question.

elongation

initiation

translocation

termination

translocation

For elongation in prokaryotic cells, which factor hydrolyzes GTP to provide energy for binding of the next tRNA to the A site?

Multiple choice question.

EF-Ts

EF-G

eEF2

eEF1α

EF-Tu

EF-Tu

Termination of translation occurs when the ribosome reaches a ____ codon in the mRNA.

stop, termination, or nonsense

Which component of the ribosome can recognize a tRNA that is not correctly matched with an mRNA codon?

Multiple choice question.

16S rRNA

5S rRNA

50S ribosomal subunit

30S ribosomal subunit

23S rRNA

16S rRNA

The component that recognizes a stop codon at termination of translation is ______.

Multiple choice question.

a terminating transfer RNA

peptidyl transferase

23S rRNA

a protein called release factor

16S rRNA

a protein called release factor

The transfer of the polypeptide in the P site to the amino acid in the A site during elongation is catalyzed by the enzyme ____ ____.

Blank 1: peptidyl, peptidyl transferase, peptidal, or peptidyle

Blank 2: transferase

Studies of the three-dimensional structures of release factors show that they resemble the structure of ____ molecules.

tRNA or tRNAs

Movement of the ribosome so that the tRNA in the P site is shifted to the E site while the tRNA in the A site is shifted to the P site is called ______.

Multiple choice question.

initiation

translocation

elongation

termination

translocation

In prokaryotic cells, the coupling of transcription and translation refers to ______.

Multiple choice question.

translation of an mRNA beginning before its transcription has been completed.

both transcription and translation occurring in the nucleus

transcription of an mRNA occurring before its translation has been completed

both transcription and translation occurring on the ribosome

translation of an mRNA beginning before its transcription has been completed.

The stage of translation that occurs when a ribosome reaches a stop codon is called ____.

termination

Select all that apply

Which of the following occurs in eukaryotic translation but not in prokaryotic translation?

Multiple select question.

An 80S ribosome is used for translation

tRNA^f-Met is the initiator tRNA

Release factors eRF1 and eRF3 are required

Translation begins before transcription has been completed

Start codon is selected according to Kozak's rules

An 80S ribosome is used for translation

Release factors eRF1 and eRF3 are required

Start codon is selected according to Kozak's rules

At termination of translation, a stop codon is recognized by a(n) ____ ____.

Blank 1: release, release factor, or releasing

Blank 2: factor, factors, or Factor

The antibiotic chloramphenicol binds to the 50S ribosomal subunit and prevents the formation of peptide bonds. This would inhibit protein synthesis in ______ cells.

Multiple choice question.

prokaryotic

neither prokaryotic nor eukaryotic

both prokaryotic and eukaryotic

eukaryotic

prokaryotic

Release factors appear to be "molecular mimics", resembling the structure of ______.

Multiple choice question.

mRNAs

tRNAs

50S ribosomal subunits

5S rRNA

23S rRNA

tRNAs

In prokaryotic cells, translation of an mRNA begins before its transcription has been completed. This phenomenon is called ____ of transcription and translation.

coupling or coupled

Select all that apply

Which of the following is used in prokaryotic translation but not in eukaryotic translation?

Multiple select question.

tRNA^f-Met as the initiator tRNA

IF1, IF2 and IF3 as initiation factors

80S ribosomes

Shine-Dalgarno sequence to facilitate mRNA binding to the small ribosomal subunit

7-methylguanosine cap on mRNA to facilitate binding to the small ribosomal subunit

tRNA^f-Met as the initiator tRNA

IF1, IF2 and IF3 as initiation factors

Shine-Dalgarno sequence to facilitate mRNA binding to the small ribosomal subunit

Some antibiotics can be used to inhibit the growth of prokaryotic cells without harming their eukaryotic hosts because they are small molecules that bind only to prokaryotic ribosomes preventing ______.

Multiple choice question.

DNA replication

protein synthesis

the formation of mRNA

the formation of tRNA

protein synthesis