DNAmutation_repair

Question 1

types of dna damage

Answer 1

chromosoal, intrachromosoal, single strand mutations

Question 2

Name the DNA repair pathways

Answer 2

Direct reversal, MMR, NER, BER, HR, NHEJ

Question 3

Major reason for double strand DNA

Answer 3

To correct damage via the other strand

Question 4

List enviromental factors that cause mutation

Answer 4

heat, radiation, chemical carcinogens, diet, infectious agents (virus), pro-carcinogens

Question 5

carcinogen process from cigarette smoke, produced when oxidized in cell

Answer 5

benzo[a]pyrene

Question 6

UV rays cause this distortion in DNA

Answer 6

covalent dimers of pyrimidine bases, usually T

Question 7

spontaneous changes that damage DNA

Answer 7

oxidative damage, hydrolytic attachment, uncontrolled methylation

Question 8

Example of depurination

Answer 8

G or A leave nt

Question 9

Example of Deamination

Answer 9

C converted to U

Question 10

inherited defect of colorectal cancer

Answer 10

MLH1 mismatch repair (MMR) defect

Question 11

describe base excision repair (BER)

Answer 11

glycolase recognizes error, AP sugar phostpate removed (sites with out Purine or Pyrimidine), polymerase adds new nt

Question 12

descrive nucleotide excision repair (NER)

Answer 12

complex recognizes a pyrimidine dimer, cut made on both side and helicase removes damaged strand

Question 13

genetically heterogenous, autosomal recessive disease of defective DNA repair, extra sensitive to UV radiation

Answer 13

xeroderma pigmetosum (XP)

Question 14

causes of double strand break repair

Answer 14

radiaiton, oxidizing agents, replication errors and metabolic cellular products, related to aging

Question 15

method of repairing double-strand break repair

Answer 15

non-homologous end joinging (NHEJ)

Question 16

more difficult method to repair DSB

Answer 16

homologous end-joining

Question 17

genetic exchange between a pair of homologous DNA, involves sequences, involves Brca1, Brca2

Answer 17

homologous recombinatoin

Question 18

proteins used for DSB repair

Answer 18

RecA/Rad51

Question 19

Uses PARP, Ku protein, DNA-PK, ligase to repair damage

Answer 19

NHEJ

Question 20

defect in ATM causes neurodegeneration, cancer, genome instability

Answer 20

AT

Question 21

common to many cancers, an important G1 checkpoint control gene

Answer 21

p53

Question 22

Unusual chromosome number

Answer 22

aneuploidy

Question 23

common to hematopoietic cancers

Answer 23

translocations

Question 24

skipping over DNA lesions

Answer 24

translesion synthesis (TLS)

Question 25

spontanous repair of damage

Answer 25

direct reversal

Question 26

chromosomal (large scale) DNA damage

Answer 26

large double stranded breaks, translocations, aneuploidy

Question 27

intrachromosomal damage

Answer 27

deletions and duplications

Question 28

single strand small scale mutations

Answer 28

small deletions and duplications, point mutations