Kandpal - DNA Repair

Question 1

What are the type of mutations of repair proteins?

Answer 1

Homologs of mutS and mutL

Question 2

What type of damages of post replcation errors?

Answer 2

Depurination,Deamination, UV Damage (Pyrimidine dimers), Heat, Extreme pH, Radiations, substances in environment

Question 3

What are the consequences of DNA damage

Answer 3

DNA will have an altered sequence during next round of replication.

Question 4

Survival of a cell is dependant on?

Answer 4

Genetic stability

Question 5

What is a transition error?

Answer 5

Substitution of a prryimidine with another pyrimidine or a purine with another purine.

Question 6

What is transversion error?

Answer 6

Substitution of a pyrimidine with a purine or vice versa

Question 7

What is frameshift error?

Answer 7

Due to addition/deletion of bases (codon)

Question 8

What is the 1st level of replair during replication.

Answer 8

Proofreading - 3’ to 5’ exonuclease activity of DNA polymerase.

Question 9

What removes mismatched nucleotides?

Answer 9

The 3’ to 5’ exonuclease during proofreading

Question 10

What happens when replication errors are missed by proofreading activity?

Answer 10

Distortion in the DNA helix is recognized and repaired by strand directed mismatch repair

Question 11

For a mismatched E. Coli, both stands are methylated at what junction?

Answer 11

Adenine

Question 12

What recognizes mismatched bases?

Answer 12

MutS

Question 13

What scans the DNA where the “nick” to determine the newly replicated DNA?

Answer 13

MutL

Question 14

What is the percentage of colon cancer cases that are familial (run in the family)?

Answer 14

10 to 15%

Question 15

What are the 2 familial colon cancers?

Answer 15

HNPCC (Hereditary non-polyposis colon cancer) and FAP (Familial adenomatous polyposis)

Question 16

When you remove a purine from a nucleotide, what is left over?

Answer 16

A base-less sugar and cytosine will convert into a uracil.

Question 17

Can thymine be deamination?

Answer 17

NO. It has no amino group

Question 18

What does 5-methyl cytosine can be deaminated?

Answer 18

Yes. Into thymine

Question 19

Can you create a deletion in deamination?

Answer 19

No only in depurination.

Question 20

What is base excision repair?

Answer 20

Specific base is removed and repaired

Question 21

What is nucleotide excision repair?

Answer 21

A stretch of DNA is removed and a new strand with the correct base is synthesized.

Question 22

What is the Yeast repair names for excision repair?

Answer 22

RAD3

Question 23

What is the Yeast repair for post-replication repair?

Answer 23

RAD 6

Question 24

What is the Yeast repair for recombination -mediated repair?

Answer 24

RAD52

Question 25

DNA or RNA, what is RAD3 part _____ polymerase?

Answer 25

RNA

Question 26

When does double strand breaks occur?

Answer 26

During Recombination and Ionizing radition

Question 27

What 2 processes repair double strand breaks?

Answer 27

Homologous end joining (HEJ) and Non Homologous end joning (NHEJ)

Question 28

Since BRCA1 and BRCA2 are defects in double stranded break repair, what do BRCA1 and BRCA2 stand for?

Answer 28

Breast Cancer gener 1 and gene 2. Predispose to both Breast and Ovarian cancer.

Question 29

What is the percentage of breast cancer cases that are familial?

Answer 29

5%

Question 30

What is the susceptibility to breast cancer?

Answer 30

Autosomal dominant

Question 31

What is Werner Syndrome?

Answer 31

An Autosomal recessive disease. Causes cataracts, changing of skin conditions, short stature, premature graying, thinning of hair.

Question 32

What is Bloom syndrome?

Answer 32

Autosomal recessive. Stunted growth, sunlight sensitivity, chromosome breakage, immunologic deficiency, infertility, increased risk for neoplasia. DOES NOT INVOLVE 3’-5’ EXONUCLEASE ACTIVITY.