Lb L3

Question 1

Enzymes of DNA replication

Answer 1

Dna topoisomerase
Dna helicase
Dna pol
Dna ligase
Ssbp

Question 2

Replisome

Answer 2

Polymerase + accessory enzymes

Question 3

Dna pol3 is…

Answer 3

Used for dna replication

Question 4

Dna pol 1 is used in

Answer 4

Dna repair

Question 5

Steps for dna replication in prokaryotes

Answer 5

DnaA binds to oriC-
DnaA melts DNA using ATP to become single stranded
DnaA recuirta 2* DnaB complexes= helicase

Question 6

Ter sites

Answer 6

Make sure same speed — replication

Question 7

Tus proteins

Answer 7

Binds with ter sites to stop helicase action by dnaB

Question 8

Yeast initiation sites

Answer 8

ARS — autonomously replicating sequences

Question 9

Eukaroytes have only one origin of replication
T/F

Answer 9

FALSE- MULTIPLE REGION

Question 10

Eukaryotoc replication - start sites depend on

Answer 10

Chromatin landscape
Chromation w specific histone marks allows replication to begin

Question 11

ORS in eukaryotic replication

Answer 11

Protein complex
Binds to dna at many sites
Binding occurs before S phase
Marks potential replication origins

Question 12

MCM helicase (eukaryotic)

Answer 12

MCM2-7 is the helicase
Unwinds dna
ORC hels load MCM

Question 13

MCM is loaded in active form
T/F

Answer 13

FALSE
MCM is loaded ininactive form
Activated after S phase

Question 14

Why do cells load extra MCM

Answer 14

Backup

Question 15

How is MCM2-7 helicase activated

Answer 15

CDC45 + GINS1-4 = activatin of MCM2-7 helicase

Question 16

Activated helicase is called

Answer 16

CMG helicase

Question 17

How is cell cycle controlled in dna replication

Answer 17

Phosphorylation
Key cycle kinases add phosphate groups to proteins to ensure — 1. replication happens one per cycle
2. Starts at S phase

Question 18

Orc-mcm2-7— activated via GINS1 + CD45 —CMG HELICASE- replisome— phosphorylatiopmn

Question 19

Types of eukaroytic polemerase

Answer 19

13 diff
Diff roles in replication, repair, mitochondria

Question 20

Eukaryotic pol used in dnas replication

Answer 20

Alpha— synthesis of RNA-DNA primers- start of okazaki frag
Delta— lagging strand pol
Epsilon—leading strand pol

Question 21

Proteins require to remove RNA primers

Answer 21

Rnase H1- removes RNA primers
FEN1- removes pol alpha DNA
Pol delta- fills section
DNA ligase- seals nick

Question 22

Function of FEN1

Answer 22

Removes pol alpha primers

Question 23

Cells shorten every cycle - what prevents loss of genes

Answer 23

Telomers

Question 24

Repetitive sequence in telomers

Answer 24

TTAGGG in humans

Question 26

Enzyme telomerase is a reverse transcriptase that can add on to the ends to extend the chromosome • Lagging strand machinery then fills in the complementary strand

Answer 26

acts as age checker

Question 27

Brain size is affected by changes to proliferation during neurogenesis

Answer 27

Needs lots of stem cells produced early in brain development rapid early growth of neural stem cells require rapid growth and accurate dna repl