REPLICATION OF DNA

Question 1

4 fundementals of DNA REPLICATION

Answer 1

1) allow CELL REPLICATION
2) SEMICONSERVATIVE
3) replication direction 5’->3’
4) BI-DIRECTIONAL

Question 2

in 3’ of the DNA what group can i found

Answer 2

OH

Question 3

in 5’ of the DNA what group can i found

Answer 3

PHOSPHATE GROUP

Question 4

3 stages of dna replication

Answer 4

1) initiation
2) elongation
3) termination

Question 5

4 enzymes of INITIATION (part of dna replication)

Answer 5

1) pre replication protein complex (PRPC)
2) single strand binding protein (SSBD)
3) helicase
4)topoisomerasi

Question 6

2 actions of pre replication protein complex (PRPC)

Answer 6

1. separate A-T bonds in the ORI (origin of replication)
2. create REPLICATION BUBBLE

Question 7

2 things about ORI

Answer 7

1. rich area of A-T BONDS
2. they are multiple in EUKARYOTIC

Question 8

2 things about single strand binding protein

Answer 8

1. prevents PARENTAL STRANDS REANNEALING (reconnection)
2. protects from NUCLEASIS (they break phosfodiester bonds)

Question 9

2 things about HELICASE

Answer 9

1. separate the strands
2. requires ATP

Question 10

def SUPER COILS

Answer 10

DNA bunching up (si arriccia) because of the action of helicase

Question 11

3 things about TOPOISOMERASES

Answer 11

1. alleviate SUPER COILS
2. 3 types (I, II, IV)
3. has 2 arms (nuclease and ligase)

Question 12

function of NUCLEASE

Answer 12

break phosphodiestere bonds

Question 13

function of LIGASE in the TOPOISOMERASES

Answer 13

resteaches (rilega) parts of DNA after UNWIND the supercoils

Question 14

2 topoisomerases used by eukaryotic cells

Answer 14

I and II

Question 15

2 topoisomerases used by procariotic cells

Answer 15

II and IV

Question 16

which topoisomerases use ATP

Answer 16

II and IV

Question 17

4 enzymes used in the ELONGATION (stage of dna replication)

Answer 17

1. primase
2. dna polymerase III
3. dna polymerase I
4. ligase

Question 18

3 functions about PRIMASE

Answer 18

1. lay down RNA PRIMERS
2. reads 3’->5’
3. synthesize 5’ ->3’

Question 19

direction of LEADING STRAND

Answer 19

3’->5’

Question 20

direction of LAGGING STRAND

Answer 20

5’ -> 3’

Question 21

5 things about DNA POLYMERASE III

Answer 21

1. needs 3’ oh of RNA PRIMER
2. READ 3’-> 5’
3. synthesize 5’-> 3’
4. has PROOF READING FUNCTION
5. EXONUCLEASE ACTIVITY (for complementary base nucleotide)

Question 22

2 things about OKAZAKY FRAGMENTS

Answer 22

1. multiple RNA primers
   2.multiple DNA primers

Question 23

4 things about DNA polymerases I

Answer 23

1. READ 3’-> 5’
2. synthesize 5’-> 3’
3. PROOF READING FUNCTION
4. EXONUCLEASE ACTIVITY (for RNA primers)

Question 24

differance between DNA POLY 3 and 1

Answer 24

Direction of EXONUCLEASE ACTIVITY
POLY 3= 3’-> 5’
POLY 1= 5’-> 3’

Question 25

function of lygase

Answer 25

fuse DNA end together of OKAZAKY FRAGMENTS

Question 26

2 things about TELOMERES

Answer 26

1. = ends of cromosomes
2. do not code for DNA

Question 27

why dna become shorther during a lot of replication

Answer 27

because telomeres (ends of cromoses ) do not code for RNA so they sacrificare themself4