Final: DNA Lesion & Mutation Types Flashcards Preview

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Flashcards in Final: DNA Lesion & Mutation Types Deck (18)
1

what is a damaged DNA site called?

lesion

2

how many DNA lesions does a cell have/day

10,000

3

what can DNA lesions lead to?

mutations

4

failure to fix a lesion

if not fixed before next DNA replication it can lead to a mutation

5

can a cell recognize a mutation?

no, it can only recognize lesions

6

what is a DNA mutation

any change in the DNA base sequence

7

3 types of DNA mutations

point mutation (single base change)

insertion

deletion

8

what can mutations arise from

copy errors in replication (DNA polymerase)

DNA lesions that cause copy errors

errors in repair of DNA lesions

errors in replication or recombination

9

types of DNA lesion

nicks, gaps

base dimers

modified bases

AP sites

intercalating agents

base analogues

double strand breaks

10

what is a nick

broken bond between nucleotides in the backbone of one side in dsDNA

11

what is a gap

a string of missing nucleotides on one side of dsDNA

12

what is a base dimer

chemical bond forms btw two adjacent bases

thymine is most common

13

what is a modified base

any way a base could be chemically changed into something other than A,T,G,C

14

common base modifications

oxidation

alkylation: methylation/ethylation

AP site

15

what is an AP site/hole

when a base is completely missing

usually a-purinic site: no G/A

sometimes a-pyrimidinic site: no T/C

16

what is an intercalating agent?

flat molecules that slip inbetween DNA bases

17

what is a base analogue

molecules that look like normal bases

the cell uses them in DNA instead

5-bromo-uracil is mistaken for thymine

18

double strand break (DSB)

a cut through dsDNA

could have missing bases