Unit 1 - Topic 5 - Protein control of cell division - Section D - Control of programmed cell death Flashcards
How is apoptosis triggered
By cell death signals that can be external or internal
Examples of external and internal death signals
The production of death signal molecules from lymphocytes is an example of an external death signal. DNA damage is an example of an internal death signal.
What does an external death signal molecule do
Binds to a surface receptor protein and trigger a protein cascade within the cytoplasm
What does an internal death signal molecule do
An internal death signal resulting from DNA
damage causes activation of p53 tumour-suppressor protein
What do both types of death signal result in
The activation of caspases (types of protease
enzyme) that cause the destruction of the cell
Why is apoptosis essential during the development of an organism
To remove cells no longer required as development progresses or during metamorphosis
When may cells initiate apoptosis
In the absence of growth factors
