Chapter 15

Question 1

what was the hersey and chase study

Answer 1

t2 virus to see what contribute to gene, if dna or protein. virus infected wirh bacteria

Question 2

What is chromosome made of

Answer 2

DNA and Protein

Question 3

backbone of DNA

Answer 3

Phosphate-sugar-phospate-sugar

Question 4

DNA measures

Answer 4

5’ 3’ double helix antiparallel

Question 5

3’ 3’ is attached to what

Answer 5

hydroxyl attached to carbodeoxyribose

Question 6

5’ 5’

Answer 6

phospate attached to a 5-carbon

Question 7

what are the names of the DNA components

Answer 7

Adine, thymine, guanine, cytosine.

A=t c=g

Question 8

A-G are …

Answer 8

purines, double ring

Question 9

C,T,U are…

Answer 9

PurimiDINES, single ring

Question 10

which is a stronger bond

Answer 10

C and G

Question 11

what are the 3 hypothesis for DNA replication

Answer 11

conservative
semiconservative
dispersive

Question 12

semiconservative

Answer 12

half and half. open it, synthesise = 1 new 1 old

Question 13

conservative

Answer 13

open it up= syntesise= old one stick together

Question 14

dispersive

Answer 14

a bit of old a bit of new, plucking in

Question 15

what did meselson and stahl do

Answer 15

grew ecoli in nitrogenous bases to see dna replication. results show semiconservative replication. nitrogeouns to trace the dna

Question 16

what is the DNA catalyzer

Answer 16

DNA plymerase. catalise dna syntesis, photocopy dna, make polimer of dna. and can only add deoxyribonucleotides to the 3’ end of growing DNA

Question 17

Which are the monomers

Answer 17

Ribose and the DNTP’s A,G,C,T

Question 18

what does DNA syntesis do to potential energy

Answer 18

increase it

Question 19

endergonic

Answer 19

require energy

Question 20

what is the formation of the phospodiester bonds

Answer 20

dehydration syntesis

Question 21

what puts the backbone of dna together

Answer 21

dehydration syntesis

Question 22

Bacteria DNA

Answer 22

circular, bidirectional

Question 23

DNA helacase

Answer 23

Break hydrogen bonds and open the double helix apart

Question 24

Binding protein SSBP/s

Answer 24

attach to each single strant and prevent them from closing together again

Question 25

topoisomerase function in dna

Answer 25

cut dana and rejoints the dna to release the coiled tension

Question 26

what is the leading strand

Answer 26

the strand that is directional 5' 3' towards the fork

Question 27

the lagging strand

Answer 27

slows down falls behind

Question 28

Primase function

Answer 28

syntesise new ran on the lagging strand so fork can open

Question 29

what are the steps for dna replication

Answer 29

split them HELICASE > single strand binding protein to keep them apart> topoise somerase > primase > DNA polymerase

Question 30

FUnction of Helicase

Answer 30

catalyses the breaking hydrogen bonds between base parings and opens the double helix up.

Question 31

Single Strand Binding DNA binding Proteins

Answer 31

stablish single strand DNA and prevents from closing down

Question 32

Topoisomerase function

Answer 32

Cuts to reveal tention and rejoins DNA

Question 33

Primase

Answer 33

catalyses the syntesis of RNA in the lagging strand

Question 34

DNA polimerase II

Answer 34

Extend the leading strand

Question 35

sliding clamp function

Answer 35

Holds Dna polymerase in place during strand expention

Question 36

DNA polimerase I funcition

Answer 36

Removes the RNA primer and replaces it with DNA

Question 37

DNA ligase function

Answer 37

catalizes okazaki fragments into continous strand

Question 38

what are okazaki fragments

Answer 38

lagging strand is sunthesized as short discontinuous fragments

Question 39

what joins okazaky fragments together

Answer 39

DNA ligase

Question 40

WHat is a replisome

Answer 40

contrains the enzyme responsible for DNA synthesis around the replication fork

Question 41

Telomers are what

Answer 41

the end of linear chromosomes

Question 42

The replisome contains what

Answer 42

the enzyme responsible for DNA synthesis around replication fork

Question 43

DNA!! polimerase cannot add to the end with no primer so it becomes shorter eveyrtime

Answer 43

shorter chromosomes by 5o and 100 nucleotides

Question 44

DO telomeres contain genes

Answer 44

no

Question 45

Telomeres function

Answer 45

replicate telomeres using RNA template

Question 46

does somatic cells have telomeres ?

Answer 46

No

Question 47

what happens to cell division if your telomeres are shorter

Answer 47

they do not divide, division is shut

Question 48

cancer cells have telomeres

Answer 48

!!!

Question 49

how acurate is dna replication

Answer 49

very acurate. one mistale every 1 billion cases

Question 50

what is the function of a repair enzyme

Answer 50

Remove defected bases and replace then with correct ones. recognice demove incorrect fill in with correct

Question 51

what recognices UV light damage

Answer 51

Nucleotide exicion system. DNA ligase link the repaied strand to the original damage dna

Question 52

who did experiemnt what showed dna copied by semiconservative

Answer 52

meselson and Stah