LEC: DNA repair mechanisms

Question 1

DNA damage types

Answer 1

Endogenous
Exogenous

Question 2

Enumerate endogenous damage types

Answer 2

 Cellular metabolic processes
 Mismatch of DNA bases
 Hydrolysis
 Oxidation
 Alkylation

Question 3

Enumerate exogenous damage types

Answer 3

 Environmental factors
 UV radiation
 Ionizing radiation (IR: Xrays and Gamma rays)
 Chemical agents

Question 4

Term for losing cell division

Answer 4

Senescence

Question 5

Enumerate the damage types repaired by base excision repair (BER)

Answer 5

Hydrolysis
Oxidation
Alkylation

Question 6

Identify the damage type repaired by MMR

Answer 6

Mismatch of DNA bases

Question 7

Enumerate the damage type repaired by Nucleotide Excision Repair (NER)

Answer 7

UV radiation

Question 8

Enumerate the damage type repaired by double-strand breaks

Answer 8

Ionizing radiation
Chemical agents

Question 9

This mut protein is responsible for the recognition in the bulge or wrong DNA nucleotide during MMR

Answer 9

Mut S

Question 10

This mut protein scissors the wrong DNA nucleotide during MMR

Answer 10

Mut H

Question 11

This mut proteins activates Mut H and helps it completely break the strand during MMR

Answer 11

Mut L

Question 12

This DNA polymerase adds the correct DNA during MMR

Answer 12

DNA pol 1

Question 13

This repair system attacks the nitrogenous base of the DNA

Answer 13

Base Excision Repair (BER)

Question 14

This endonuclease removes the non-nitrogenous wrong base during BER

Answer 14

AP endonuclease

Question 15

This polymerase will fill in the gap during the BER to make another nucleotide

Answer 15

pol beta

Question 16

This enzyme will join the new nucleotide base with the rest of the strand during BER

Answer 16

DNA ligase

Question 17

UV light attacks the DNA strand and the pyrimidine will have _____ bonds which results to a kink in the structure which destructs the double helix structure

Answer 17

covalent

Question 18

This UvrABC protein detects the dimerization of pyrimidine during NER

Answer 18

UvrA

Question 19

This UvrABC protein calls the UvrC to break the wrong nucleotide during NER

Answer 19

UvrB

Question 20

This UvrABC protein removes all the hydrogen bonds present in the nucleotide strand

Answer 20

UvrD1

Question 21

The worst part of double strand breaks

Answer 21

Losing a sequence of nucleotide

Question 22

In what phase does the homologous recombination happen during double strand breaks repair system?

Answer 22

S and G2 phases

Question 23

This is involved in the search for homologous DNA and helps with invasion

Answer 23

RAD51

Question 24

The RAD51 is responsible in the creation of the __-loop with ____ formation

Answer 24

d-loop with cris-cross formation

Question 25

Difference between the non-cross over and cross over HR repairs

Answer 25

Non-cross: straight line
Cross: exchange in chromosome

Question 26

This repair system does not require templates

Answer 26

Nonhomologous end-joining