Kandpal - DNA Repair Flashcards Preview

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Flashcards in Kandpal - DNA Repair Deck (32):
1

What are the type of mutations of repair proteins?

Homologs of mutS and mutL

2

What type of damages of post replcation errors?

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

3

What are the consequences of DNA damage

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

4

Survival of a cell is dependant on?

Genetic stability

5

What is a transition error?

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

6

What is transversion error?

Substitution of a pyrimidine with a purine or vice versa

7

What is frameshift error?

Due to addition/deletion of bases (codon)

8

What is the 1st level of replair during replication.

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

9

What removes mismatched nucleotides?

The 3' to 5' exonuclease during proofreading

10

What happens when replication errors are missed by proofreading activity?

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

11

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

Adenine

12

What recognizes mismatched bases?

MutS

13

What scans the DNA where the "nick" to determine the newly replicated DNA?

MutL

14

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

10 to 15%

15

What are the 2 familial colon cancers?

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

16

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

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

17

Can thymine be deamination?

NO. It has no amino group

18

What does 5-methyl cytosine can be deaminated?

Yes. Into thymine

19

Can you create a deletion in deamination?

No only in depurination.

20

What is base excision repair?

Specific base is removed and repaired

21

What is nucleotide excision repair?

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

22

What is the Yeast repair names for excision repair?

RAD3

23

What is the Yeast repair for post-replication repair?

RAD 6

24

What is the Yeast repair for recombination -mediated repair?

RAD52

25

DNA or RNA, what is RAD3 part _____ polymerase?

RNA

26

When does double strand breaks occur?

During Recombination and Ionizing radition

27

What 2 processes repair double strand breaks?

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

28

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

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

29

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

5%

30

What is the susceptibility to breast cancer?

Autosomal dominant

31

What is Werner Syndrome?

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

32

What is Bloom syndrome?

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