Ch. 5.2- DNA replication

Question 1

Define DNA replication

Answer 1

The process by which a cell replicates its genome before it divides.

Question 2

Define mutation

Answer 2

Errors made while copying DNA.

Question 3

Define enzyme

Answer 3

Proteins that facilitate chemical reactions in a cell.

Question 4

What does the enzyme: helicase do?

Answer 4

Unwinds DNA

Question 5

What does the enzyme: primase do?

Answer 5

Builds RNA primers: multiple primers are required to build the lagging strand.

Question 6

What does the enzyme: DNA polymerase III do?

Answer 6

Main enzyme that copies DNA on the leading and lagging strand.

Question 7

What does the enzyme: DNA polymerase I do?

Answer 7

Replaces RNA primers with DNA: also has a role in DNA repair.

Question 8

What does the enzyme: Ligase do?

Answer 8

Forms phosphodiaster bonds to seal nicks in the DNA sugar phosphate backbone. Important in DNA replication and DNA repair.

Question 9

What do the enzymes: Gyrase and Topoisomerases do?

Answer 9

Relieves torsion stress that develops ahead of helicase as DNA unwinds.

Question 10

What is the primosome made up of?

Answer 10

Helicase and unwind the DNA- by breaking the hydrogen bonds between the nitrogen bases and “unzips” the DNA
Primase to lay down RNA primers