Dna Repair

Question 1

What do all excision repairs use

Answer 1

Enzymes
The back bone of the dna as a template

Question 2

What is dna mismatch repair and how would it be fixed

Answer 2

Incorrect base added and never removed
Protein signals enzyme, glycosylase cuts out, polymerase adds a new one

Question 3

What are the diseases that would be associated with nucleotide excision repair

Answer 3

Xeroderma pigmentosum
Cockaynes syndrome
Trichothiodysyrophy

Question 4

What is base excision repair

Answer 4

Damaged DNA bases
Short patch: fixing the single damaged base
Long patch repair: fixing a larger area

Question 5

What is the normal method for the fixing of a base excision repair

Answer 5

Glycosylase identifys and cuts out the damage
Endonuclease would add an OH to the 3’ area
Polymerase can build from this end

Question 6

What are the Types of nucleotide excision repair

Answer 6

Global genomic repair
Transcription coupled repair

Question 7

How to the types of NER differ

Answer 7

Transcription coupled: rna pol 2 would move across and would produce mRNA until sees the damage
Global genomic: sensoric repair. Moves across until the damage would be identified

Question 8

What is necessary for the replication-coupled repair (recombinant repair)

Answer 8

Dna helicase

Question 9

What disease would occur from the deficiency in the helicase molecules

Answer 9

Bloom’s syndrome
(Autosomal recessive disorder)

Question 10

What happens if BRAC1/BRAC2 genes are inherited

Answer 10

Increased chance of cancer and mainly would be breast cancer
Big genes also so would have a higher chance of containing a large amount of mutations

Question 11

What type of cancer does mismatch repair lead to

Answer 11

Colorectal cancer
Microsatellite instability and the the autosomal dominant inherited mismatch repair
Accumulation of mutations would lead to cancer

Question 12

What are the symptoms of cockaynes syndrome

Answer 12

Dwarfism
Neurological defects
Light sensitivity

Question 13

What are the symptoms of xeroderma pigmentosum

Answer 13

Light sensitivity, Severe pigmentation of skin, neural defects, increased chance of early onset skin cancer

Question 14

What are the symptoms of trichothiodystrophy

Answer 14

Facial abdominalites, light sensitivity, sulfur deficiency brittle hair, short stature

Question 15

What causes a simple double strand break

Answer 15

X rays

Question 16

What is special about replication-coupled repair

Answer 16

The polymerase would be able to use a different pathway as can switch template strands
Needs helicase