Final Exam

Question 1

Viral DNA can insert itself into the infected cell’s DMA and become part of cellular DNA. Viral genes can remain _________ for a long period of time

Answer 1

dormat

Question 2

What kind of molecule has enzymatic activity that is RNA-dependent DNA-polymerase, RNA exonuclease activity, and DNA-dependent DNA-polymerase activity

Answer 2

Reverse transcriptase (RT)

Question 3

What is AZT

Answer 3

it inhibits reverse transcriptase and is incorporated into newly synthesized DNA

Question 4

How is CCA attached in tRNA

Answer 4

5’ end has P attached, 3’ ends in CCA

Question 5

What is another name for tRNA and what is its structure

Answer 5

clover leaf
secondary structure, folds into L-shaped tertiary structure

Question 6

___________ tRNA has an amino acid attached

Answer 6

Charged

Question 7

The genetic code is degenerate: more than one codon for some AA -> some tRNAs an recognize more than one ______

Answer 7

codon

Question 8

What are the three binding sites of tRNA

Answer 8

A: entry point
P: peptide chain grows
E: empty tRNA leaves

Question 9

Does dissociation or assembly need energy

Answer 9

Dissociation only needs energy

Question 10

What does IF-1, 2, 3 block

Answer 10

IF-1 blocks A site
IF-2 blocks P site
IF-3 blocks E site

Question 11

What is the three steps of initiation

Answer 11

mRNA is positioned on the ribosome (IF-1, IF-3)
tRNA brought to ribosome (IF-2, GTP)
50s ribosomal subunit joins complex (hydrolysis by IF-2)

Question 12

What are the three steps of elongation

Answer 12

Binding of incoming tRNA (EF-Tu, GTP) (hydrolysis by EF-Tu)
Peptide bond formation
Translocation (EF-G, GTP) (hydrolysis by EF-G)

Question 13

What are the three steps of termination

Answer 13

Binding of release factors (RF1 or RF2)
Hydrolysis of polypeptidyl-tRNA (RF1 or RF2)
Dissociation of components (EF-G, GTP, RF3, IF3, RRF) (hydrolysis of EF-G)