Cell Division and Cancer

Question 1

Describe the cell cycle.

Answer 1

Interphase:
G1: commits to cell replication
P53 checks for any defects in the DNA, if none is present then activates cyclin and CdK
S: DNA replicates and Chromosomes double
G2: Organelles are copied and cytoplasm expands
G0: rest

Question 2

Functions of Checkpoints.

Answer 2

Controls
Co-ordinates
Detects defects

Question 3

Explain how Apoptosis occurs.

Answer 3

Program cell death
The balance between BAX-protein and BCL-2
Gene Mutation leads to p53 increases in BAX-proteins
This increases the permeability of the mitochondrial membrane.
Hence the release of cytochrome c.
Cyt C converts procaspases into caspases which induces apoptosis
BCL-2 inhibits this