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Flashcards in DNA replication Deck (38):
1

information is copied during ____ and distributed during ____.

interphase
cell division

2

parts of the cell cyle

G1 to S to G2 to mitosis

3

period of cell growth before the DNA is duplicated

gap one (G1)

4

period when the DNA is duplicated

synthesis phase (S phase)

5

period after DNA is duplicated and cell prepares for division

gap two (G2)

6

G1, S, and G2 make up the

interphase

7

four general characteristics of DNA replication

chemically uni-directional
semi-conservative
spatially bi-directional
semi-discontinuous

8

scientists that proved DNA replication was semi-conservative

meselson and stahl

9

DNA replication occurs in specific nuclear or nucleoid compartments

replication factories

10

the region of DNA that first separates and replication begins

origins of replication

11

DNA replication proceeds in both directions away from the origin of replication

bi-directional replication

12

the point of separation of double-stranded DNA at which incorporation of nucleotides occurs during DNA replication

replication fork

13

where each separated polynucleotide strand serves as a template for the synthesis of a single new complementary strand

semi-conservative replication

14

the synthesis of DNA fragments that occurs in the lagging strand during DNA replication

semi-discontinuous replication

15

the name given to the discontinuous fragments of DNA synthesized in the lagging strand

okazaki fragments

16

five basic steps for DNA replication

1. helicase unwinds parental double helix
2. single stranded binding proteins stabilize unwound DNA
3. leading strand is synthesized continuously in 5' to 3' direction by DNA polymerase
4. lagging strand is synthesized discontinuously by RNA primase laying a primer down so DNA polymerase can form an okazaki fragment
5. DNA ligase joins okazaki fragments

17

unwind and stabilize the duplex DNA to form the replication fork

initiation

18

DnaA proteins bind to origin of replication

initiation factors

19

DnaB protein catalyzed the ATP-dependent unwinding of duplex DNA

helicase

20

prevent supercoiling and tangling of DNA during unwinding; binding ahead of the replication fork, nick super coiling DNA, and relaxes stress allowed by uncoiling

topoisomerases

21

prevents re-annealing of the separated single strands, protects against nuclease degradation

ssDNA binding proteins

22

5' to 3' synthesis of complementary DNA

replication

23

an RNA polymerase synthesizes a short RNA primer

primase

24

extends the RNA-primed chain and is the main replication enzyme

DNA polymerase III

25

later replaces RNA with DNA and using 3' to 5' exonuclease activity to ensure accuracy

DNA polymerase I

26

joins DNA fragments

DNA ligase

27

subunits of DNA polymerase that use ATP to load DNA into the beta clamp unit

tau
gamma
beta
beta prime

28

hold/guides DNA, opens and closes to allow passage of DNA in DNA polymerase

beta sliding clamp

29

an enzyme that removes nucleotides from the end of a polynucleotide strand

exonuclease

30

subunit of DNA polymerase that performs 5' to 3' polymerase reaction

alpha subunit

31

subunit that performs exonuclease

epsilon subunit

32

what makes up the DNA replicating machine called a replisome

two copies of DNA polymerase III
primosome DNA unwinding proteins

33

contains primase and auxiliary proteins

primosome

34

repair enzymes normally present in cells where they repair low levels of DNA damage

DNA polymerase II and IV

35

bind to sites on opposite side of DNA loop, inhibit helicase and prevent further progression of replication fork (in prokaryotes)

ter binding proteins

36

play a role in replication termination in eukaryotes by preventing the ends of DNA from being lost

telomeres

37

an enzyme that restores telomere sequence

telomerase

38

how does telomerase work

extends the unreplicated end so the lagging strand can be completed