Module 02 - Section 01

Question 1

What are the 5 phases of the Eukaryotic Cell cycle?

Answer 1

G0 Phase, G1 Phase, S Phase, G2 Phase, M Phase

Question 2

Which phases of the cell cycle - cells are not actively dividing

Answer 2

G0, G1

Question 3

Which phase is not technically part of the cell cycle

Answer 3

G0

Question 4

First growth phase of cell cycle

Answer 4

G1

Question 5

Which phase of cell cycle; cell replicates its entire genome

Answer 5

S phase

Question 6

Cell cycle; 2nd growth phase

Answer 6

G2

Question 7

Cell cycle: cell division occurs

Answer 7

M phase

Question 8

Describe # of chromosome in G1 phase

Answer 8

2n: cells are diploid containing two copies of each chromosome

Question 9

Describe chromosome in S phase

Answer 9

DNA replication is occurring - chromosomes are duplicated

Question 10

Describe # of chromosome in G2 phase

Answer 10

4n: cells are tetraploid, containing four copies of each chromosome

Question 11

Describe # of chromosome in M phase

Answer 11

2n: each daughter cells contains a complete set of chromosomes

Question 12

Arthur Kornberg discoveries (3)

Answer 12

(1) assay for measuring the amount of DNA synthesis that is occurring
(2) Several heat-stable factors are needed for the DNA synthesis reaction (nucleoside triphosphates)
(3) DNA polymerase I purification using multi-step fractionation of the bacterial lysate

Question 13

Describe briefly the Purification of Polymerase by Kornberg

Answer 13

Step 1: break the bacteria by sonication
Step 2 to 5: remove DNA and RNA from the mixture
Step 6: use salt to precipitate some proteins and leave others in the solution (based on their proteins)
Step 7: use ion exchange chromatography to give a more purified product

Question 14

What is sonication?

Answer 14

Applying sound energy to agitate particles in a sample

Question 15

Describe Kornberg’s experiments for requirements for polymerization reaction

Answer 15

Determined the maximal incorporation of deoxyribonucleotides into DNA under various conditions. They performed 8 experiments, each one removing one or more factors and radiolabelling dTTP to monitor the effect on incorporation

Question 16

What were the results of Kornberg’s requirements of the polymerization reaction results?

Answer 16

In each experiment where a factor was removed, there was almost complete loss of the incorporation of radiolabelled dTTP into DNA

Question 17

What do the results of Kornberg’s requirements mean for the polymerization reaction?

Answer 17

The requirements of the polymerase reaction are:

• all 4 nucleotides present in the cell
• an intact DNA template
• a Mg++ cofactor for the polymerase