Control of Cell Proliferation Flashcards Preview

Molecules to Man > Control of Cell Proliferation > Flashcards

Flashcards in Control of Cell Proliferation Deck (16):
1

Why is the cell cycle controlled

To maintain genome integrity

2

Why is the cell cycle controlled

To maintain genome integrity

3

What does G1 involve

Growth + Prep for DNA replication

4

What does G2 involve

New DNA, organelles and cytoplasm for new cells

5

What does G1 checkpoint do

Ensure cell large enough to divide
If large enough, release growth factor
If no, switch to non-dividing state G0

6

What does the G1/S checkpoint do

Check damaged DNA

7

What does the G2 checkpoint do

Ensure DNA replication is successful
If not - cell death

8

What does the M checkpoint do

Ensure all chromosomes attached to mitotic spindle by kinetochore
If not - cell death

9

What enzymes regulate cell proliferation

Kinase
Cyclin dependent kinase - drives and accumulates during interphase

10

What happens to Cdk in G2

Enough Cdk to form M-Cdk which drives cell through mitosis

11

What happens to M-Cdk

Switches off by initiating process which destroys Cdk.

12

What does retinoblastoma protein do in the absence of growth factors

Bind to transcription regulators of genes to prevent cell cycle

13

What does retinoblastoma protein do in the presence of growth factors

Cdk phosphorylases pRB so it release binding of transcription factor regulators

14

What does p53 do

When it recognises damaged DNA, it activates transcription of p21 which inhibits Cdk so there is time to repair DNA
If too severe, p53 induces apoptosis

15

What are some of the consequences of checkpoint failure

Proliferation without growth factors
Replication of damaged DNA
Division of cells with wrong chromosome number

Gene instability = increase mutation = increase cancer

16

What mutations can lead to cancers

Mutation of oncogenes and tumour suppressor genes