Apoptosis

Question 1

What is the p53 protein and what is its role?

Answer 1

The p53 protein is a regulatory protein that operates in the G1 and G2 cell cycle checkpoints. Its role is to detect DNA damage within a cell prior to reaching mitosis and dividing.

Question 2

3 major purposes of increase in p53 protein levels

Answer 2

halting of cell cycle
enzyme repair of DNA
activation of apoptosis

Question 3

What happens if p53 proteins are damaged?

Answer 3

If p53 proteins are damaged, they can no longer perform their three purposes. This will result in the division of cells with damaged DNA and the rapid accumulation of mutated cells within the organism, which can lead to cancer.

Question 4

What is apoptosis?

Answer 4

Apoptosis, or programmed cell death, is a highly controlled process that results in a eukaryotic cell committing “cellular suicide”. It is important in maintaining the overall health and balance of an organism.

Question 5

What are caspases?

Answer 5

Caspases are a class of enzymes that cleave proteins. They are activated in response to signals triggering apoptosis. A specific type of caspase breaks down the mitochondria, which releases a protein complex known as cytochrome c. The release of cytochrome c activates other caspase enzymes which commence the breakdown of the nucleus and other organelles.