Why is the addition of the 5' cap structure critical?

an mRNA to be translated in the cytoplasm, is needed to protect the growing RNA chain from degradation in the nucleus by 5' exonucleases, the cap also helps the transcript bind to the ribosome during the protein synthesis

(True or False) RNA polymerase III synthesizes rRNAs involved in facilitating protein synthesis by the ribosome

False

Which of the following is an mRNA processing reaction?

Removal of introns from the heterogenous nuclear RNA

Which of the following sites on a gene is important for recognition of the beginning the ends of intron sequences?

splice sites GU and AG

Splicing of a newly synthesized RNA molecule to remove introns and join exons

Occurs in the nucleus and involves a complex of small nuclear RNA and protein molecules

What will be the sequence of the single-stranded RNA transcribed from the following segment of double-stranded DNA?

5'-TTGCACCTA-3'

3'-AACGTGGAT-5'

5'-UUGCACCUA-3'

Telomeres-

consist of repetitive DNA sequences found at the ends of chromosomes.

The nucleotide is composed of

a pentose sugar, a phosphate, and a base (G, C, A, T)

How many hydrogen bonds bind G and C and how many bind A and T?

3 hydrogen bonds bind G and C and 2 hydrogen bonds bind A and T

DNA is composed of the following bases-

adenine (A), guanine (G), cytosine (C), thymidine (T)

The nucleotides in each strand are linked by-

strong (covalent) chemical bonds

The nucleosome consists of

a complex of 8 histone proteins ( 2 molecules of each histone H2A, H2B, H3, and H4) with double-stranded DNA wound around it

Which of the following statements about histone proteins is correct?

Nuclear DNA associates with histone proteins to form chromatin

The phosphodiester bonds are bonds that form between

3'-OH groups of the deoxyribose sugar on one nucleotide with the 5' phosphate groups on the adjacent nucelotide

Chromatin consists of-

very long double-stranded DNA molecules, nearly an equal mass of rather small basic proteins termed histones, as well; as smaller amounts of nonhistone proteins and a small quantity of ribonucleic acid (RNA)

Modification of histone proteins by acetylation will-

increase the transcription of target genes

(true or false) DNA polymerases "read" a parental strand 5' to 3' and synthesize a complementary antiparallel new strand 3' to 5'

false

DNA replication occurs during the ____________ phase of the cell cycle

synthesis

__________ enzyme unwinds and breaks the hydrogen bonds between nucleotides of 2 DNA strands for DNA replication

DNA helicase

DNA primase-

adds RNA primer to DNA strand for replication

Exonuclease-

removes RNA primers from the lagging strand

Okazaki fragments-

are the DNA synthesized on the lagging strand

Single-stranded DNA binding proteins-

prevent premature annelaing of the single-stranded DNA to double-stranded DNA

___________ is an enzyme that catalyzes the sealing of nicks (breaks) remaining in the DNA polymerase fills the gaps left by RNA primers

DNA ligase

__________________ enzymes relieve torsional stress in DNA by inducing reversible single-stranded breaks in DNA

topoisomerases

(true or false) Telomerase shortening is recognized as and is a part of the normal aging process

false

(true or false) Telomerase adds a series of DNA repeats to the leading strand. This addition allows the lagging strand to be completed by DNA polymerase

false

mismatch repair-

correcting the mismatches of normal bases that fail to maintain normal waston-crick base pairing

base excision repair-

correct the spontaneous depurination and spontaneous deamination that happens to bases present in DNA

Nucleotide excision repair-

removes UV light-induced DNA damage as well as DNA damage from environmental chemicals

Double-stranded DNA repair-

correct the severed strands of DNA caused by ionizing radiation, oxidative free radicals, or chemotherapeutic agents

(true or false) non homologous end joining is more accurate in repairing severed DNA than homologous recombination.

false

(true or false) UCA conversion to CCA is a silent mutation

False (its missense)

(true or false) The A site binds an incoming aminoacyl-tRNA, The P site codon is occupied by peptidyl-tRNA, The E site is occupied by the empty tRNA

True

In a patient with cystic fibrosis caused by the F508 mutation, the mutant cystic fibrosis transmembrane conductance regulator (CFTR) protein folds incorrectly. The patient's cells modify this abnormal protein by attaching ubiquitin molecules to it. What is the fate of this modified CFTR protein?

It is degraded by the proteosome

The stop and initiation codons are?

Stop codons: UAG, UAA, UGA

Start codon: AUG

_________ is a dictionary that identifies the correspondence between a sequence of nucleotide bases and a sequence of amino acids

The genetic code

26S proteosome is a large complex of proteins made of a central core ___________ and a _______ regulatory particle and either end

20S, 19S

The carboxyterminal _____________ residue in ubiquitin binds to a _____________ residue in the protein to be degraded

glycine, lysine

_________________ is the first therapeutic proteasome inhibitor to be tested in

Bortezomib

Necrosis is-

cell death in response to tissue damage

Why does autophagosome fuse with a lysosome?

To form autolysosome and hydrolyse and degrade autophagosome content

Ubiquitination of proteins occurs through the following steps except-

The ubiquitin-regulatory enzyme (E1) to initially bind ubiquitin

Which of the following molecules marks a protein for degradation by a proteosome?

Ubiquitin

(true or false) Proteins with long half-lives are degraded by the proteosome

False

Short-lived proteins with half-life in seconds and minutes are degraded by utilizing-

ATP dependent protein degradation pathway by the proteosome

(true or false) Ubiquitination occurs by tagging a "bad" protein, This increases its likelihood of being degraded. Proteasomes don't necessarily need to identify a protein that has a ubiquitin tag in order to degrade it

False

Function of CDK 4 ?

progression past the restriction point at the G1/S boundary

Function of CDK2?

Initiation of DNA synthesis in early S phase

Function of CDK 1?

The transition from G2 to M

S phase cyclins include-

type E cyclins and cyclin A

What is prophase?

chromatin condenses into defined chromosomal structures called chromatids

What is prometaphase?

is when the spindle microtubules bind to kinetochores and chromosomes are pulled by the microtubules of the spindle

What is metaphase?

is when chromatids aligned at the equator of the spindle, halfway between the two poles

What is anaphase?

is when the mitotic poles are pushed further apart as a result of polar microtubules elongating

cyclin-dependent kinases are degraded by-

proteosome

G1 phase-

is generally both a growth phase and preparation time for DNA synthesis

G0 phase-

is a resting state

S phase-

is where DNA replication occurs

G2 phase-

is a time of preparation for the nuclear division of mitosis

All of the following are correct regarding interphase except-

Specialized protein complexes, called kinetochores, form, and associate with each chromatid

In mitosis, the parent cell divides to make _________ chromosomes in ________ phase of the _____________

92 chromosomes, synthesis, interphase

In meiosis, _________ haploid cells and each containing __________ chromosomes

4, 23

Why one cell undergo apoptosis will not affect neighboring cells? (weird ass wording)

Phagocytic cells release cytokines including interleukin-10 (IL-10) and transforming growth factor-B(TGF-B)

How long does necrosis take?

Days

The marker for senescence is-

senescence-associated beta-galactosidase enzyme activity (SA-B-gal)

Replicative senescence depends on-

The number of cell divisions and cell type

Which of the following characteristics of senescent cells in incorrect?

Can be induced into cell cycle

(remain metabolically viable, but can not enter the cell cycle under any condition)

Mitochondria of apoptotic cells release _________ but remain within the membrane blebs

cytochrome C

_____________ is a passive, pathological process induced by acute injury or disease

Necrosis

Why is mtDNA vulnerable to oxidative stress?

Due to the close proximity between the sites of ROS production and mtDNA

A population of cells is being grown in the laboratory and the total number of viable cells is observed to decrease. Analysis of Bax protein reveals an increase in its expression. Which of the following findings may be used to confirm that apoptosis is occurring in this cell population?

Phosphatidylserine on the outer membrane leaflet

______________ is an active, normal, physiological process that removes individual cells without damaging neighboring cells or inducing inflammation

Apoptosis

Zymogen becomes activated through __________ when they reach their proper sites of action

cleavage

Phosphorylation occurs on the hydroxyl groups of _______ or, less frequently, _________ residues in a protein

- serine, threonine

-tyrosine

Glycosylation involves the addition of __________ in ____________

carbohydrate/sugar, a target protein

________ and _________ residues of the a chains of collagen are extensively hydroxylated in the ER

proline & lysine

(true or false) Attachment of lipids, such as farnesyl groups, can help anchor proteins in membranes

True

The pancratic zymogen ________ becomes activated to ________ in the small intestine

- trypsinogen

-trypsin

Portions of the protein chain must be removed by specialized ____________ resulting in the release of an active molecule

endoproteases

The steady-state level of individual RNA species in a cell is determined by

Both the rate of decay and transcription

Transcription is inhibited in heterochromatin because

The DNA is packaged so tightly that it is inaccessible to the protein responsible for RNA transcription

Centromeres serve in all of the following except:

allow mitotic spindles to attach to the chromosome during cell division

separate the two arms of the chromosome

replicate DNA

replicate DNA

(true or false) Proteins that have a half-life of minutes to hours are coded by stable mRNA

False

Which of the following DNA sequences would have the highest melting temp.?

- CGCAACCATCCG

- CGCAATAATACA

- CGTAATAATACA

- CATAACAAATCA

- CGCAACCATCCG

(true or false) Spliceosome converts the primary transcript into mature mRNA

true

RNA processing control includes all of the following except-

- mRNA capping

- Poly(A) tail

- removal of introns

- basal transcriptional factors

basal transcriptional factors

Insertion of many extra glutamine residues results in

Huntingtons disease

(true or false) Specific transcription factors are not important for tissue-specific gene expression and for cell growth and differentiation

false

Which of the following sites on a gene is important for recognition of the beginning and the ends of intron sequences?

Splice sites GT and AG

The addition of the 5' cap structure is critical for all the following except

protects the mRNA from premature degradation by 3' exonucleases

Please complete the complementary DNA start of AGTCGTA

TCAGCAT

(true or false) The consensus sequence for promoters typically has the sequence TATA

true

(true or false) General transcription factors are needed for priming transcription

true

(true or false) A DNA molecule is composed of two parallel DNA strands

False

(true or false) DNA replication is unidirectional and starts in several different locations at once

False

(true or false) CAAT box sequences determine how frequently the transcription event occurs

True

__________________ synthesizes rRNAs involved in facilitating protein synthesis by the ribosome

RNA polymerase I

________________ is responsible for the synthesis of mRNA and miRNAs

RNA polymerase II

___________ catalyzes the synthesis of tRNAs

RNA polymerase III

The following sequence, when found in the 3' UTR, is a signal for early degradation

AUUUA

The positively charged amino acids help histones-

bind tightly to the negatively charged sugar-phosphate backbone of DNA

Telomeres serve to

protect the chromosome from degradation

Which of the following is an mRNA processing reaction

Removal of introns from the heterogenous nuclear RNA

Basal promoter sequences have-

The proximal component, generally the TATA box, directs RNA polymerase II to the correct site

A distal component specifies the frequency of initiation (CAAT and GC boxes)

Modification of histone proteins by acetylation will-

increase the transcription of target genes

All of the following are characteristics of the genetic code except-

overlapping

specificity

universality

degeneracy

overlapping

(true or false) DNA replication is a semiconservative process because each of the two daughter strands has half new DNA and half old DNA

true

The difference between leading and lagging DNA strands is-

Continuous (leading strand) vs. discontinuous (lagging strand)

The leading strand is the one in which 5' to 3' synthesis proceeds in the same direction as the replication fork movement.

The lagging strand is the one in which 5' to 3' synthesis proceeds in the direction opposite to the direction of the fork movement

_______ codes for proteins

mRNA

_______ catalyzes protein synthesis

rRNA

__________ brings amino acids to mRNA

tRNA

_______ regulates gene expression

miRNA

(true or false) DNA polymerases "read" a parental strand 5' to 3' and synthesize a complementary anti-parallel new strand 3' to 5'

False

Which of the following statements is false regarding transcription in eukaryotic cells?

Transcription takes place in the cytoplasm

The regulatory region consists of

both basal and regulated expression

Nucleotides bind other nucleotides on the other DNA strand by _______________ bonds

hydrogen

(true or false) 61 of the 68 codons code for the 20 common amino acids

false

Which of the following statements is correct?

- The amount of protein present in a cell depends on its rate of synthesis and rate of degradation

- Ribosomes are cytoplasmic organelles that are encapsulated by a single membrane

- Because the two strands of DNA are complementary, the mRNA of given gene can be synthesized using either strand as a template

- an mRNA may contain the sequence ATTGACCCCGGTCAA

The amount of protein present in a cell depends on its rate of synthesis and rate of degradation