DNA Replication In Eukaryotes

Question 1

Replisome for eukaryotes. Helicase corresponds to?

Answer 1

MCM

Question 2

SSB corresponds to

Answer 2

Replication protein A

Question 3

Primase corresponds t

Answer 3

Pol alpha/primase which contains both primase and DNA polymerase activities

Question 4

DNA polymerase iii

Answer 4

Pol delta

Question 5

The y complex clamp loader

Answer 5

Replication factor C

Question 6

Beta sliding clamp

Answer 6

PCNA - trimeric sliding clamp

Question 7

RNase H

Answer 7

Nuclease that is specific for RNA in RNA/DNA hybrids - excises primers

Question 8

In prokaryotes whereas DNA polymerase III elongates both leading and lagging strands…

Answer 8

Polymerase delta elongates lagging strand and epsilon elongates leading strand

Question 9

What is a retrovirus

Answer 9

It is a type of virus that inserts a copy of its RNA genome into DNA of the host cell it invades this changing the genome of that host cell

Question 10

What is the enzyme that retroviruses use and what is its activity

Answer 10

Reverse transcriptase, and it uses an RNA template to make DNA

Activities, 5’ to 3’ rna directed DNA polymerase
5’ to 3’ dna directed DNA polymerase
Exoribonuclease (degrades RNA in RNA:DNA hybrid)

Question 11

Function of DNA B at initiation

Answer 11

Helicase activity

Question 12

Function of DNA C at initiation

Answer 12

DNA C loads helicase to ori c

Question 13

Function of dNA A

Answer 13

Identifies ori C

Question 14

Which cells have low level of telomerase activity

Answer 14

Somatif cells

Question 15

Thymidine diamers

Answer 15

Uv irradiation causes covalent bonds between adjacent T vases so they need to be separated

Done by NER

Question 16

Causes of DNA damage

Answer 16

Misincorporation of dNTPs during replication
Spontaneous demanination of bases(cytosine to uracil. Release of nh3)
Exposure to x Ray’s causing Nick’s and breaks in DNA
Uv irradiation
Various chemical interactions