DNA replication and repair

Question 1

During DNA replication, both strands are templates used for ….

Answer 1

Generating a new DNA strand

Question 2

Templates are ________ to each other

Answer 2

Complementary

Question 3

After replication, each original parent strand is paired with a newly synthesized …….

Answer 3

Daughter strand

Question 4

What does helicase do?

Answer 4

unzips genes

Question 5

What does topoisomerases do?

Answer 5

cut phosphate backbones

Question 6

What does ssDNAbp

Answer 6

binds to nucleotide ends

Question 7

What do the sliding clamp and clamp loader do?

Answer 7

Keep DNA polymerase on the strand

Question 8

What does primase do

Answer 8

Makes short RNA primer to start replication

Question 9

What do DNA polymerase do?

Answer 9

Replicates DNA

Question 10

What does DNA ligase do?

Answer 10

Enzymes that connect a phosphate backbone

Question 11

Replication is initiated where?

Answer 11

The origin of replication

Question 12

For a piece of DNA replicated, it must contain what

Answer 12

an ori

Question 13

Proteins bind at the ori and break hydrogen bonds, generating a short single stranded region called what

Answer 13

Replication bubble

Question 14

The replication bubble has two replication forks where double stranded DNA will be ….

Answer 14

Seperated

Question 15

For linear chromosomes there are single or multiple ori and replication bubbles

Answer 15

Multiple

Question 16

Once replication bubbles are created, the single strand regions of DNA within the bubble are copied by what

Answer 16

DNA polymerase

Question 17

Nucleotides are added based on what

Answer 17

base pairing

Question 18

DNA polymerase forms phosphodiester bonds between what

Answer 18

Nucleotides

Question 19

DNA polymerase can only add a nucleotide to a what

Answer 19

Existing chain of nucleotides

Question 20

DNA polymerase can only add a nucleotide to the 3’, or 5’?

Answer 20

3’

Question 21

How does the nucleic acid begin?

Answer 21

A piece of RNA is added first, then DNA builds off the RNA

Question 22

The leading strand of RNA is _________ synthesized

Answer 22

continously

Question 23

The lagging strand of RNA is ______ synthesized

Answer 23

discontinuously

Question 24

DNA polymerase require an existing chain, so what has to be used to begin DNA synthesis

Answer 24

A different type of polymerase

Question 25

An RNA polymerase (primase) created a ______

Answer 25

Short chain of RNA that has a 3’ end

Question 26

DNA polymerase can bind that 3’ end of the RNA and extend by adding

Answer 26

dNTPs

Question 27

DNA synthesis is a complex process that requires additional proteins besides __________

Answer 27

DNA polymerase

Question 28

Additional proteins form a replication machine where

Answer 28

A replication Fork

Question 29

Some additional proteins involved include

Answer 29

-Helicase
-Topoisomerase
-Single binding protein

Question 30

Double stranded DNA is antiparallel, which means that new daughter strands are made is what direction

Answer 30

Opposite

Question 31

Replication steps

Answer 31

1. DNA separates at the ori
2. Single strand binding proteins keeps strands separated
3. Helicase binds and opens the replication fork
4. Topoisomerase relieves coiling pressure caused by helicase
5. Primase makes a primer
6. DNA polymerase extends that primer
7. One strand is made in the same direction that helicase moves (towards the fork)
8. the other strand (lagging) is made moving away from the fork
9. RNA primers are removed by DNA polymerase
10. The gaps are sealed by DNA ligase

Question 32

Topoisomerase relieves what

Answer 32

Coiling pressure

Question 33

The discontinuous strand (lagging) is produced in pieces called ________

Answer 33

Okazaki fragments

Question 34

What are two issues with Okazaki fragments

Answer 34

1. Contains RNA primers
2. Have gaps