exam 2 lecture 16

Question 1

the human genome consists of how many base pairs

Answer 1

6x10^9

Question 2

how long does replication of the human genome take

Answer 2

8 hours

Question 3

200,000 bp are replicated per second due to

Answer 3

multiple replication orgins

Question 4

a mistake in replication causes

Answer 4

a mutation that can lead to cancer

Question 5

number of errors per replication

Answer 5

one error per one billion base pairs

Question 6

DNA polymerase adds to what end

Answer 6

the 3’ hydroxyl group

Question 7

T/F DNA polymerizes the DNA in the 5’-3’ direction so it reads from the 3’-5’ direction

Answer 7

true

Question 8

which form of DNA polymerase is the major enzyme for DNA replication

Answer 8

DNA polymerase eplison

Question 9

hoe much energy is needed to replicate 1 nucleotide

Answer 9

2 ATP

Question 10

what are the 4 dNTPs (deoxyribonucleotides)

Answer 10

dATP, dTTP, dCTP, dGTP

Question 11

cell replication stops when there are no more

Answer 11

dNTPs

Question 12

what bond is formed between 2 nucleotides

Answer 12

phosphoester bond with alpha-phosphate of dNTP

Question 13

what is the continuous strand of replication

Answer 13

leading strand

Question 14

what is the discontinuous strand of replication

Answer 14

lagging strand

Question 15

what are the segments of the lagging

Answer 15

okazaki fragments

Question 16

what links the okazaki fragments

Answer 16

ligase

Question 17

why is RNA used during replication

Answer 17

easier to remove then can be replaced with DNA once errors are fixed

Question 18

what unwinds the DNA

Answer 18

helicase

Question 19

how is replication started

Answer 19

a primase synthesizes a short RNA primer

Question 20

how is the primer removed

Answer 20

RHase H- ribonuclease H

Question 21

what does the DNA polymerase having the exonuclease activity mean

Answer 21

it synthesizes but can go back to fix mistake by cleaving the nucleotides added

Question 22

what hold the DNA polymerase on the strands so it does not dissociate

Answer 22

PCNA proliferating cell nuclear antigen

Question 23

what does the replisome do

Answer 23

causes the leading and lagging strand to be synthesizes at the same time

Question 24

what is the telomere

Answer 24

the end of replication containing thousands of TTAGGGs

Question 25

how much is the DNA shortened by each replication

Answer 25

50-100 base pairs

Question 26

how many replications causes cell dealths

Answer 26

40-60 replications

Question 27

what does telomerase do

Answer 27

adds TTAGGGs to the telomere to increase cell life

Question 28

T/F not all cells have telomerase

Answer 28

true

Question 29

T/F telomerase causes cancer cells to live and replicate

Answer 29

true

Question 30

what three steps are in the polymerase chain reaction

Answer 30

denaturation, annealing, extension

Question 31

how many times is the PCR cycle repeated

Answer 31

25-30 times

Question 32

what does the PCR cycle require

Answer 32

thermocycler and a heat-resistant polymerase

Question 33

what can damage DNA internally

Answer 33

hyroxy radical, superoxide, deamidation, depurination

Question 34

what can damage DNA externally

Answer 34

carcinogens like, mustard gas, cured meat, chemotherapy, cigarettes, UV radiation

Question 35

base excision repair

Answer 35

damaged base is removed, AP site formed then removed and resynthesized

Question 36

nucleotide excision repair

Answer 36

a stretch of damage is removed and then resynthesized

Question 37

what is XP- xeroderma pigmentosum

Answer 37

defect do no nucleotide repair

Question 38

double strand break repairs are

Answer 38

homologous (accurate) and non-homologous end joining (error-prone)

Question 39

what are the functions of p53

Answer 39

activates DNA repair proteins, arrests cell cycle, may initiate programmed cell death