front 1 What did Rosalind Franklin do? | back 1 She used X-Ray diffraction to see crystal structure of DNA |
front 2 What did Watson and Crick do? | back 2 They figured out the Double Helix Structure of DNA |
front 3 What di Erwin Chargaff find? | back 3 found that A and T pair and G and C pair |
front 4 What did Meselson and Stahl discover? | back 4 That DNA replicates Semiconservatively. They also found out that it was NOT conservative or dispersive |
front 5 What did Frederick Griffith discover? | back 5 that there is a “Transforming Factor” responsible for heredity |
front 6 What did Avery and MacLeod suggest? | back 6 That DNA was the transforming factor in hereditary material |
front 7 What kind of expirement did Avery hold? | back 7 Recreated Griffith experiments but destroyed (1 at a time) proteins, lipids, RNA, and DNA |
front 8 Hershey and Chase proved what? | back 8 That DNA is hereditary material and is found in viruses too |
front 9 How did Hershey and Chase prove their theory? | back 9 They tagged the Sulfur of a bacteriophage (proteins) and the phosphorus (DNA). Thus phage infected a cell, and all new viruses created had that P tag. NOT the S one.Proving finally that DNA was the genetic material |
front 10 What does semiconservatively mean? | back 10 only one strand of new DNA comes directly from parent molecule |
front 11 How did Meselsohn Stahl rule out conservative replication? | back 11 He labeled both strands of DNA and let it replicate. Through this they discovered that there was one strand of parent DNA in each new molecule |
front 12 How did Meselsohn Stahl rule out dispersive replication? | back 12 By replicating the 2 molecules again and again found there were just the two original strands, and 6 new strands |
front 13 What did the fred griffith experiments discover? | back 13 There was a Transforming Principle responsible for heredity |
front 14 What were the 3 results from the free griffith experiment? | back 14 SIII virus kills mice, RII lets mice live, SIII heat killed lets mice live. This means that some transforming principle passed from the shocked SIII to the RII |
front 15 Why does the transforming principle happen a lot in bacteria? | back 15 Because DNA is super stable so is hard to get rid of, so
in |
front 16 DNA runs in what direction? | back 16 It runs in 2 antiparallel strands. (5'-3') |
front 17 How are the DNA strands held together? | back 17 By hydrogen bonds between A-T and G-C |
front 18 A-T have how many bonds? | back 18 2 |
front 19 G-C have how many bonds? | back 19 3 |
front 20 The DNA backbone is held together | back 20 phosphodiester bonds |
front 21 DNA is found in what form? | back 21 The B form naturally in living organisms |
front 22 Base Stacking leads to what? | back 22 the turns in the DNA double helix which forms major and minor grooves |
front 23 In Eukaryotes DNA Replication is what? | back 23 Bidirectional and proceeds from multiple replication origins |
front 24 In bacteria DNA replication is what? | back 24 bidirectional but has ONE replication origin |
front 25 Consensus Sequences are what? | back 25 Unique in prokaryotes and eukaryotes, conserved across species, and essentially tell DNA polymerase where to bind and start replication |
front 26 What does the helicase enzyme do? | back 26 It breaks DNA hydrogen bonds and unwinds DNA |
front 27 These unwound strands are stabilized by what? | back 27 SSBs |
front 28 DNA polymerase is the enzyme that does what? | back 28 Extends DNA strands to replicate DNA |
front 29 DNA polymerase requires what? | back 29 RNA Primer made by primase |
front 30 On bacteria DNA polymerase III is the what? | back 30 main replication enzyme |
front 31 In replication, the 5-3 new strand will always be elongated... | back 31 continuously and it makes the leading strand |
front 32 The 3-5 strand is elongated in short sections called | back 32 Okazaki fragments |
front 33 Okazaki fragments are later joined together by what? | back 33 ligase |
front 34 What does DNA polymerase I do? | back 34 its 5-3 exonuclease activity to remove the primer and then its 5-3 polymerase activity to elongate the gaps in the strand |
front 35 DNA is heavily coiled, so what enzyme helps alleviate the tension during replication? | back 35 topisomerase |
front 36 Telomeres serve as what? | back 36 caps at the end of linear chromosomes. They help to combat the
shortening of chromosomes in each replication |
front 37 Telomeres are fomred by what? | back 37 They are formed by T loops and protected by the protein sheltrin |
front 38 What are the 4 nucleotides of RNA? | back 38 adenine, uracil, cytosine, and guanine (no T) |
front 39 Is RNA double-stranded or single-stranded? | back 39 single stranded (so it is way less stable) |
front 40 RNA includes ribose sugar, what does this mean? | back 40 It includes an extra OH on the 2’ carbon |
front 41 What does Messenger RNA (mRNA) do? | back 41 made by protein coding genes and is intermediate between |
front 42 What does Ribosomal RNA (rRNA)? | back 42 NOT from protein coding genes...works with proteins to form ribosomes |
front 43 What does Transfer RNA (tRNA) do? | back 43 NOT from protein coding genes...binds to amino acid to add it into growing protein chain |
front 44 Telomerase RNA does what? | back 44 provides template for synthesizing telomeres |
front 45 Small Nuclear RNA (snRNA) play a role in what? | back 45 In mRNA processing and splicing out introns |
front 46 What does Micro RNA (miRNA) do? | back 46 pairs with mRNA to alter stability |
front 47 Small Interfering RNA (siRNA) is cut from what? | back 47 double stranded RNA to also alter mRNA stability |
front 48 The template Strand is what? | back 48 the strand of DNA that RNA polymerase binds to and assembles a complementary strand of nucleotides to |
front 49 The other strand of DNA is called what? | back 49 coding strand. It is where the actual genes being transcribed |
front 50 True or false. The Promotor Region is immediately upstream of transcription start site (more to the 5’ end) | back 50 true |
front 51 RNA Polymerase is ninds to what? | back 51 The promoter region |
front 52 What does the Transcription Region contain? | back 52 sequences to help stop transcription (close to 3’ end) |
front 53 Describe the process of transcription? (for prokaryotes) | back 53 The sigma subunit actually identifies the promotor region and allows
RNA Polymerase to bind. The RNA Polymerase holoenzyme complex then
unwinds the DNA to form an open promotor complex. After 8-10
nucleotides have been transcribed, the sigma subunit
then |
front 54 What does DNA do in transcription? (for prokaryotes) | back 54 the DNA continues to unwind in front of RNA Polymerase and reforms the double helix behind it |
front 55 What happens in transcription termination? (for prokaryotes) | back 55 1. Intrinsic Termination happens in most prokaryotes 2. Rho-Dependent Termination needs the protein rho |
front 56 What is intrinsic termination? | back 56 The termination sequence is a bunch of inverted repeats, followed by a tail of Adenines. ex: GGGGGGCCCCAAAAAAAAA |
front 57 What does the rho protein do? | back 57 Rho moves up the mRNA, forces it to form a loop, detaching it from the DNA and kicking RNA Polymerase off |
front 58 In eukaryotic transcription RNA Polymerase I transcribes what? | back 58 rRNA |
front 59 In eukaryotic transcription RNA Polymerase II transcribes what? | back 59 mRNA, miRNA, siRNA and snRNA |
front 60 In eukaryotic transcription RNA Polymerase III transcribes what? | back 60 tRNA, miRNA, siRNA one snRNA, and one rRNA |
front 61 Enhancer sequences can bind what? | back 61 proteins around the promotor to enhance the level
of |
front 62 Silencer sequences bind proteins to bend what? | back 62 DNA so it can’t be transcribed as easily...decreases gene expression |
front 63 What are some of the post-transcriptional modifications for eukaryotes? | back 63 1. Capping 5’ mRNA (Guanylyl transferase adds a special Guanine
nucleotide to the 5’ end of the mRNA to 2. 3’ Poly-A tail (A polyadenylation sequence is at the 3’ end of the mRNA . The mRNA is cleaved after this sequence and then PAP and CPSF then add up to 200 As.) |
front 64 How does capping 5' mRNA help transcription? | back 64 This protects the mRNA molecule from rapid degradation and helps with later translation |
front 65 How does a 3' poly-a tail help transcription? | back 65 This protects mRNA from degradation and helps with translation |
front 66 What is intron splicing in eukaryotes? | back 66 Eukaryotic mRNA is unique in that intronic (non-coding) regions and spliced (cut) out of final transcript. This is important in correct protein formation |
front 67 Describe intron splicing in eukaryotes? | back 67 In splicing, you have a 5’ splice site, 3’ splice site, and a
branch |
front 68 How do we produce alternating proteins? | back 68 1. Alternative Intron Splicing 2. Alternative Processing 3. Alternative Polyadenylation 4. RNA Editing and processing |
front 69 How many amino acids are there? | back 69 20 with unique chemical properties |
front 70 What is the r group of amino acids? | back 70 They are distinct and give these amino acids their unique |
front 71 The ribosome catalyzes the formation of what? | back 71 a peptide bond between amino acids which forms a growing polypepetide chain |
front 72 What is a codon and what does it code for? | back 72 A group of 3 nucleotides on an mRNA strand and they code for one amino acid |
front 73 What are the start and stop codons of translation? | back 73 start codon: 5’ AUG (always) end codon: UGA, UAG, UAA 3’ |
front 74 The starting codon AUG codes for what amino acid? | back 74 methionine (met) |
front 75 What is before or after the start and end codons? | back 75 small Untranslated regions (UTRs) on the 5’ and 3’ |
front 76 What are ribosomes? | back 76 a combination of rRNA and proteins found in ALL living organisms |
front 77 What doe ribosomes do? | back 77 They bind mRNA, facilitate pairing of correct tRNAs carrying amino
acids to catalyze the formation of peptide bonds to |
front 78 Each ribosome has how many sites? | back 78 3 (A, P, E) |
front 79 What is the A site? | back 79 where tRNAs carrying amino acids first bind to the ribosome (NOT THE FIRST ONE THOUGH) |
front 80 What is the P site? | back 80 where the ribosome transfers amino acids into the polypeptide chain |
front 81 What is the E site? | back 81 where the tRNA will leave the ribosome after dropping off its amino acid |
front 82 Eukaryotic ribosomes have __ and ___ subunits to create a ___ ribosome | back 82 40s and 60s to create 80s |
front 83 Prokaryotic ribosomes have ___ and ___ subunits to create a __ ribosome | back 83 30s and 50s to create 70s |
front 84 What provides the energy for translation? | back 84 GTP |
front 85 What are initiation factors (IF)? | back 85 proteins that facilitate mRNA and ribosome binding |
front 86 What are elongation factors (EF)? | back 86 They use GTP hydrolysis to help create growing protein chains |
front 87 What are charged tRNAs? | back 87 tRNA molecules WITH an amino acid attached to them |
front 88 What are release factors? | back 88 They bind to the codon in the A site after the stop codon has been reached (basically end translation) |
front 89 What sequence is in the 5’UTR? ( for prokaryotes) | back 89 a Shine-Dalgarno sequence found in all prokaryotic mRNAs |
front 90 In prokaryotes the first amino acid ONLY is what? | back 90 N-formylmethionine (fMET) instead of normal methionine |
front 91 The tRNA carrying the fMET amino acid will first bind to what site? | back 91 the p site (all other tRNAs will first bind to the A site) |
front 92 For eukaryotes, the small ribosomal subunit (40s here) binds to what consensus sequence? | back 92 the Kozak Sequence. (everything else is similar to prokaryotes) |
front 93 How is a tRNA charged? | back 93 aminoacyl-tRNA synthetase binds the correct amino acid to the tRNA with the correct anticodon (this uses ATP) |
front 94 How does termination occur? | back 94 The correct tRNA will have a complementary sequence to the correct codon in its anticodon stem. Once one of the three stop codons binds in the A site, a Release Factor (RF) will bind in the A site as well |
front 95 How many different codons are for the 20 amino acids. | back 95 64 including the 3 stop codons |
front 96 Our amino acid code is degenerate which means? | back 96 more than one codon can code for an amino acid ( but there are 3 exceptions - methionine and tryptophan) |
front 97 What are the 2 synonymous codons? | back 97 methionine and tryptophan (helpful in protecting against mutations) |
front 98 What is the Wobble Effect? | back 98 the third nucleotide in a codon is least important, and has
the |
front 99 true or false. In prokaryotes, the f-MET amino acid is always removed | back 99 true |
front 100 it is hypothesized that the first 15-20 amino acids act as what? | back 100 signal sequences to lead the new protein chain to other organelles for processing or packaging |
front 101 Fraenkel-Conrat proved that there were no overlapping codes by... | back 101 by showing that a single nucleotide substitution only affected one amino acid |
front 102 How do you read 3 base pairs at a time and what can it lead to? | back 102 by looking at the reading frame and it can cause frameshift mutations |
front 103 What are somatic mutations? | back 103 Mutations that occur in somatic, body cells and they can NOT be passed down |
front 104 What are germline mutations? | back 104 mutations that occur in egg/sperm cells and these CAN be passed on |
front 105 Point mutations occur where? | back 105 only one specific place in the DNA (ex: one base pair was deleted) |
front 106 Substitution Mutations occur when what happens? | back 106 when you swap one nucleotide for another |
front 107 Transitions occur when... | back 107 a purine switches with a purine (or pyrimidine for pyrimidine) |
front 108 Transversions occur when... | back 108 a purine and pyrimidine switch places |
front 109 Frameshift Mutations occur when... | back 109 when you insert or delete nucleotides NOT in a multiple of 3 (they change the reading frame of the DNA sequence and can leave it nonfunctional) |
front 110 What are the types of substitution mutations? | back 110 silent, missense, and nonsense |
front 111 What is a silent mutation? | back 111 A nucleotide is substituted, but the amino acid does NOT change (Ex: UUU and UUC both code for Phe) |
front 112 What is a missense mutation? | back 112 A nucleotide is substituted, and the amino acid DOES change |
front 113 What is a nonsense mutation? | back 113 A nucleotide is substituted and creates a premature stop codon (Ex: UAU codes for Tyr and UAG is a stop codon) |
front 114 Regulatory mutations do what? | back 114 alter the expression of the protein product but have no affect on the protein coding DNA sequence |
front 115 What are promoter mutations? | back 115 any types of mutations that occur in the consensus sequences in the promotor region. They mainly affect RNA polymerase |
front 116 RNA polymerase activity correlates to what? | back 116 the amount of protein produced |
front 117 What are splicing mutations? | back 117 They occur in the specific splice sites of introns and they can actually change the protein produced |
front 118 Cryptic Splice Site Mutations will create what? | back 118 new splice sites in mRNA, additionally changing the |
front 119 What does forward mutations mean? | back 119 Going from wild type to mutant allele |
front 120 True Reversion occurs when? | back 120 a codon receives a second mutation that restores the original amino acid |
front 121 Intragenic Reversions are what? | back 121 reversions occurring somewhere else in the gene (a frameshift fixing another frameshift mutation) |
front 122 Second-Site Reversions occur where? (also known as suppressor mutants) | back 122 in a DIFFERENT gene that compensates for the original mutation |
front 123 true or false. Most mutations in the genome are spontaneous and occur from errors in DNA replication or proofreading | back 123 true |
front 124 What is depurination? | back 124 breaks the nucleotide from the backbone, if unprepared is replaced by an A |
front 125 What is deamination? | back 125 occurs when an amino group is lost from a nucleotide |