Reactions of NA

Question 1

Name & explain the physical rxns of NA.

Answer 1

shearing

renaturation

denaturation

Question 2

Name chemical reactions of DNA?

Answer 2

SS

Question 3

Draw the dna polymerization mechanism

Answer 3

Ss

Question 4

Show the bases which are deaminated and their products.

Case of C - U

Answer 4

Ss

Question 5

List deamination agents

Name an enzyme that can reverse the C to U deamination

Answer 5

Ss

Question 6

Why U is not in DNA?

Answer 6

Ss

Question 7

What happens in depurination?

Answer 7

Purines off

N-beta-glycosidic bonds

Question 8

What happens in cross-linking? Explain the 2 repair mechanisms for that?

Answer 8

Thymine – uv – cyclobutane thymine

Question 9

Give an example for alkylation with structures.

List some chemical alkaline agents

Answer 9

Guanine –> methylguanine

Question 10

Via what the oxidation of NAs happen? Diseases it can cause?

Answer 10

O2- , H2O2 , OH’

Cock

Question 11

What is intercalation of NA? Molecules that can cause it?

Answer 11

Planar mols bw bases

Eth.br
Proflavin
Acridine O

Question 12

Show the mechanism of acid hydrolysis of NA.

Answer 12

Ss

Question 13

Give the order of stability of N-glycosidic bonds

Answer 13

dG, dA < rG, rA < dC, dT < rC, rU

Question 14

Show the mechanism of base hydrolysis of NA.

Answer 14

ss