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UCI BIO 93 FINAL EXAM
QUESTIONS AND ANSWERS| ACE
YOUR GRADES.
1. What is a transcription unit? - correct answer -The DNA that's
transcribed.
2. What are transcription factors? - correct answer -Help RNA
polymerase bind to the promoter/initiate transcription.
3. What is the transcription initiation complex? - correct answer -
The name given once RNA polymerase 2 and the transcription
factors bind to the promoter. This completes the initiation
process.
4. What does nuclease do? - correct answer -Cuts out damaged
DNA (from the environment, diet, behaviors - smoking, etc.)
5. What are telomeres and what are their purpose? - correct
answer -Special nucleotide sequences that are found at the
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ends of chromosomes for eukaryotes. They prevent important
coding DNA sequences from being degraded after every
replication cycle by creating a buffer region. THEY DO NOT
STOP THE SHORTENING OF DNA FROM OCCURRING.
6. What is a does a telomerase do? - correct answer -Lengthen
telomeres in germ cells.
7. What is a codon? - correct answer -A group of 3 nucleotides
8. DNA is __________ but not ___________. - correct answer -
redundant, ambiguous.
9. Which strand is shown 3' to 5'? - correct answer -Template
strand.
10. Which strand is shown 5' to 3'? - correct answer -Coding
strand.
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11. What are the 3 steps of transcription? - correct answer -
initiation, elongation, and termination.
12. What happens in elongation in transcription? - correct
answer -RNA polymerase untwists the two DNA strands and
creates an RNA complement 5' to 3' by reading the template
strand (3' to 5').
13. What happens in termination in transcription? - correct
answer -The pre-mRNA gets cleaved off, the RNA polymerase
falls off DNA, and it is now ready to be modified into mature
RNA.
14. Why must pre-mRNA be modified in the nucleus? - correct
answer -Must be modified in order for it to be sent to the
cytoplasm to be translated.
15. What happens in pre-mRNA modification? - correct answer -
The 5' end get as GTP cap and the 3' end gets a poly A tail in
order to help export to the cytoplasm, protect from degradation,
and allow ribosomes to attach to the 5' end. Introns (regions
that don't code for proteins) are spliced out using spliceosomes
and exons (regions that code for proteins) are joined together.
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16. What happens in translation? - correct answer -The cell
translated mRNA into a protein by assistance of tRNA in
ribosomes.
17. What are the 3 step of translation? - correct answer -
initiation, elongation, and termination.
18. What happens in initiation in translation? - correct answer -
The small ribosomal subunit will bind to the mRNA strand -- an
initiator tRNA brings methionine to the AUG codon in the P-site.
This process uses GTP instead of ATP. To match the correct
tRNA to the correct amino acid, an enzyme called aminoacyl
tRNA synthetase is used. The large ribosomal subunit comes
in, and the initiation complex is complete.
19. What happens in elongation in translation? - correct answer -
The next tRNA, carrying the next amino acid to be added to the
polypeptide chain, enters the A site of the complex. A peptide
bond is formed between the Amino Acid in the P site and the
new Amino Acid in the A site. Then, translocation occurs, in
which the tRNA in the A site moves to the P site, and the tRNA
in the P site moves to the E site. Finally, the tRNA in the E site
is ejected and the polypeptide chain is in the P site.
UCI BIO 93 FINAL EXAM
QUESTIONS AND ANSWERS| ACE
YOUR GRADES.
1. What is a transcription unit? - correct answer -The DNA that's
transcribed.
2. What are transcription factors? - correct answer -Help RNA
polymerase bind to the promoter/initiate transcription.
3. What is the transcription initiation complex? - correct answer -
The name given once RNA polymerase 2 and the transcription
factors bind to the promoter. This completes the initiation
process.
4. What does nuclease do? - correct answer -Cuts out damaged
DNA (from the environment, diet, behaviors - smoking, etc.)
5. What are telomeres and what are their purpose? - correct
answer -Special nucleotide sequences that are found at the
, Page | 2
ends of chromosomes for eukaryotes. They prevent important
coding DNA sequences from being degraded after every
replication cycle by creating a buffer region. THEY DO NOT
STOP THE SHORTENING OF DNA FROM OCCURRING.
6. What is a does a telomerase do? - correct answer -Lengthen
telomeres in germ cells.
7. What is a codon? - correct answer -A group of 3 nucleotides
8. DNA is __________ but not ___________. - correct answer -
redundant, ambiguous.
9. Which strand is shown 3' to 5'? - correct answer -Template
strand.
10. Which strand is shown 5' to 3'? - correct answer -Coding
strand.
, Page | 3
11. What are the 3 steps of transcription? - correct answer -
initiation, elongation, and termination.
12. What happens in elongation in transcription? - correct
answer -RNA polymerase untwists the two DNA strands and
creates an RNA complement 5' to 3' by reading the template
strand (3' to 5').
13. What happens in termination in transcription? - correct
answer -The pre-mRNA gets cleaved off, the RNA polymerase
falls off DNA, and it is now ready to be modified into mature
RNA.
14. Why must pre-mRNA be modified in the nucleus? - correct
answer -Must be modified in order for it to be sent to the
cytoplasm to be translated.
15. What happens in pre-mRNA modification? - correct answer -
The 5' end get as GTP cap and the 3' end gets a poly A tail in
order to help export to the cytoplasm, protect from degradation,
and allow ribosomes to attach to the 5' end. Introns (regions
that don't code for proteins) are spliced out using spliceosomes
and exons (regions that code for proteins) are joined together.
, Page | 4
16. What happens in translation? - correct answer -The cell
translated mRNA into a protein by assistance of tRNA in
ribosomes.
17. What are the 3 step of translation? - correct answer -
initiation, elongation, and termination.
18. What happens in initiation in translation? - correct answer -
The small ribosomal subunit will bind to the mRNA strand -- an
initiator tRNA brings methionine to the AUG codon in the P-site.
This process uses GTP instead of ATP. To match the correct
tRNA to the correct amino acid, an enzyme called aminoacyl
tRNA synthetase is used. The large ribosomal subunit comes
in, and the initiation complex is complete.
19. What happens in elongation in translation? - correct answer -
The next tRNA, carrying the next amino acid to be added to the
polypeptide chain, enters the A site of the complex. A peptide
bond is formed between the Amino Acid in the P site and the
new Amino Acid in the A site. Then, translocation occurs, in
which the tRNA in the A site moves to the P site, and the tRNA
in the P site moves to the E site. Finally, the tRNA in the E site
is ejected and the polypeptide chain is in the P site.
