Genetic code and DNA repication

Question 1

Unambiguous codon

Answer 1

3 bases code for exactly 1 aa

Met, Try

Question 2

Degenerate/redundant

Answer 2

multiple 3 base combos code for same aa

3rd position if wobble (matters less)

Question 3

Methionine

Answer 3

AUG

Question 4

Tryptophan

Answer 4

UUG

Question 5

Commaless/nonoverlapping

Answer 5

read in fixed sequence start to finish

exception: some viruses

Question 6

Universal

Answer 6

conserved

except human Mt

Question 7

Direction of replication

Answer 7

5’ to 3’

Question 8

Origin of replication

Answer 8

Consensus sequence (base pairs single in prokar. and multiple in eukar.); Pribnow and TATA box respectively

Question 9

Helicase

Answer 9

Unwind DNA at replication fork

Question 10

single-stranded binding proteins

Answer 10

stop DNA from re-annealing at replication fork

Question 11

DNA topoisomerases

Answer 11

ss or dsDNA breaks to add or remove supercoils

Question 12

Irinotecan/topotecan

Answer 12

Inhibit eukar. topoisomerase I

Question 13

Etoposide/teniposide

Answer 13

Inhibit eukar. topoisomerase II

Question 14

Fluoroquinolones

Answer 14

Inhibit prokar. topoisomerase II (DNA gyrase) and IV

Question 15

Primase

Answer 15

Makes RNA primer for DNAPIII initiation

Question 16

DNAPIII

Answer 16

PROKARYOTES ONLY
5’ to 3’ DNA elongation, makes lagging strand until it hits next RNA primer
Proofreading exonucl. 3’ to 5’

Stopped by drugs with modified bases

Question 17

DNAPI

Answer 17

PROKARYOTIC ONLY
Degrades RNA primer and replaces with DNA
Also has 5’ to 3’ exonuclease activity

Question 18

DNA ligase

Answer 18

Catalyzes formation of phosphodiester bonds to ligate Okazaki fragments

Question 19

Telomerase

Answer 19

EUKARYOTES ONLY
RNA dep. DNAP adds DNA to 3’ end to avoid loss of material with replication
Dyreg. in ca. to unlimited rep.