DNA Replication

Question 1

Basic Mechanism

Answer 1

DNA Helicase Unzips
Topoisomerase cuts
SSBs keep it apart
Primase creates primer
DNA Poly III synthesizes 5 to 3
DNA Poly I removes primer and makes it DNA
DNA Ligase puts together cut strands and Okasaki fragments

Question 2

3 prime overhang

Answer 2

TTAGGG repeats in Telomeres

Telomerase fixes the problem by extending off an RNA template to create telomeres

Question 3

Lagging Strand DNA Poly

Answer 3

Delta

Question 4

Leading Strand DNA Poly

Answer 4

Epsilon

Question 5

What phase does nucleotide synthesis begin

Answer 5

End of G1 (preparing for DNA synthesis)

Question 6

Bulky adducts

Answer 6

Caused by benzopyrene getting oxidized and binding with guanine

Question 7

Pyrimidine Dimers

Answer 7

formed by UV light

Question 8

HNPCC (Lynch Syndrome)

Answer 8

Caused by problems in the mismatch repair pathway,

Increased risk for many types of cancers

Question 9

Xeroderma pigmentosum

Answer 9

Mutations to the Nucleotide excision repair
Skin hypersensitive to sunlight
Highly susceptible to skin cancer

Question 10

Acceptable Wobble base pairs

Answer 10

GU
IA
IC
IU

Question 11

Prokaryote initiation of translation

Answer 11

30s subunit binds shine delgarno sequence upstream of AUG
IF1, IF2-GTP, IF3 bind
1 and 3 leave, GTP hydrolyzed
IF2 leaves and 70s binds to begin transcription

Question 12

Eukaryotic initiation of translation

Answer 12

Cap of 5 primen binds EIFs and 40s ribosomal subunit

MRNA scanned for AUG within Kozak Sequence

Question 13

Diptheria and EF2

Answer 13

His residue on eEF2 is covalently modified by diptherian toxin blocking translocation and preventing transcription

Question 14

RNA Poly I

Answer 14

rRNA

Question 15

RNA Poly II

Answer 15

mRNA and miRNA

Question 16

RNA Poly III

Answer 16

tRNA and other small proteins

Question 17

Binding of RNA transcription factors

Answer 17

TBP binds with coactivators to TATA box
TFIIA and TFIIB bind
TFIIF binds and gets RNA Polymerase to bind
TFIIE, TFIIH bind

Question 18

5 prime methylguanosice

Answer 18

CAP placed onto DNA by phosphodiester linkages, not always attached to methionine

Question 19

Stopping of eukaryotic transcription

Answer 19

AAUAAA sequence recognized

Signals for polyadenylation

Question 20

Splicing of Introns

Answer 20

Recognition of GU AG sites
U1 binds GU
U2 binds A
U1 meets up with U2 to form lasso
Exons are ligated and lasso leaves with the Us

Question 21

Components of tRNA

Answer 21

Dihydrouridine D loop
Anticodon Loop
Variable Loop
Pseudouridine and ribothymidine in TPC loop
CCA sequence at 3 prime end

Question 22

Spinal Muscular Atrophy

Answer 22

Caused by mutation in SMN1 gene
Both copies must be mutated
Additional splice site removed due to C to T mutation causing hnRNP to be able to continue blocking splicing and binding of U1 and U2

Question 23

G1 to S phase

Answer 23

CDK4/6 and Cyclin D

CDK2 and Cyclin E later

Question 24

S phase

Answer 24

CDK2 and Cyclin A

Question 25

G2 to M phase

Answer 25

CDK1 and Cyclin A/B