Chapter 11 DNA Replication

Question 1

Structure of Helix

Answer 1

2 stands composed of nucleotides A, T, C, G

*held together by hydrogen bonds

Question 2

Three Mech. for explaining DNA Replication

Which is correct?

Answer 2

Conservative
Semiconservative
Dispersive
(explain experiment and why the correct one is correct)

Question 3

Bacterial DNA Replication

Answer 3

-Single oriC
-bidirectional
Two replication forks moving in opposite directions

Question 4

Replication in Bacterial DNA initiated by:

Answer 4

binding of dnaA protein with DnaA box

Question 5

oriC Region contains 3 types of DNA sequence:

Answer 5

1) AT rich region
2) DnaA box
3) GATC Methylation site

Question 6

Topo II or Gyrase

Answer 6

Travels in front of helicase and alliveates + supercoiling

Question 7

Primase

Answer 7

syntesize RNA primers

Question 8

Leading Strand

Answer 8

Single Primer needed at oriC (DNA Poly 3 attaches)

Question 9

Lagging Strand

Answer 9

multiple primers mad away from fork and discountinous

Question 10

DNA Polymerase

Answer 10

Snythesizes DNA in leading and lagging strand

Question 11

DNA Poly 3

Answer 11

Responsible for most of DNA rep. has 10 subunits (alpha catalyzes bonds btw. nucleotides)

Question 12

DNA Poly I

Answer 12

removes RNA primers and fills in vacant area with DNA

Question 13

Okazaki Fragment

Answer 13

created only in lagging strand

Question 14

DNA Ligase

Answer 14

catalyyzes covalent bond btw. adjacent fragmens after Ok. replication

Question 15

B Subunits (of polymerase)

Answer 15

form dimer which makes a ring structure allowing polymerase to slide down the strand and synthesize at fast rate

Question 16

What is function of single strand binding proteins?

Answer 16

Bind to the strands of parental DNA and prevent them from re forming a double helix

Question 17

What do T1 subunits do?

Answer 17

Termination sequence that stops counterclockwise fork

Question 18

What does T2 subunit do?

Answer 18

Termination sequence that stops clockwise forks

Question 19

What are cantenanes?

Answer 19

Two interwined circular molecules resulting from bacterial DNA replication. Seperated by toposiermase

Question 20

Nuclear DNA has what subunits?

Answer 20

Alpha, Delta, and Epsilon

Question 21

DNA poly Epsilon involved in?

Answer 21

leading strand synthesis

Question 22

DNA poly Delta involved in?

Answer 22

Lagging strand synthesis