What is Apoptosis?
The programmed death of a cell. If a cell begins to malfunction or become damaged or unnecessary than it receives instructions to active apoptosis.
What are the two types of apoptosis?
Death Receptor Pathway or the Mitochondrial pathway
Explain the Death Receptor Pathway
Immune cells will death signalling molecules, which then get recepted by proteins located on the surface of the cell. Which when received activates caspase enzymes, initiating apoptosis.
Explain The Mitochondrial Pathway
When internal components ( DNA ) are damaged, the mitochondria detects this damage and releases cytochrome C into the cytosol. Which then binds with cytosolic proteins which activate caspase enzymes, initiating apoptosis.
What are blebbing and apoptotic bodies?
Bulging of the plasma membrane to create apoptotic bodies which are vesicles that contain cell contents which are released from a dying cell. They are developed by phagocytes.
Stages of Apoptosis
- Activation of Caspases
- Digestion of Cell Components - caspases splits/separates intracellular proteins proteins which leads to the breakdown of organelles.
- Cell shrinks - The cell and nucleus shrink as intracellular material is broken down.
- Membrane Blebbing & Breaking - as the cytoskeleton is digested, the structure of the cell wall is weakened, which leads to the membrane warping and detaching from the cell in apoptotic bodies.
What causes Cancer and Default Apoptosis
When a cells apoptosis is decreased which reduces the ability for cell death, leaving exponential cell growth resulting in tumors.
What are the two types of tumors?
Benign Tumors - Lacks the ability to spread throughout other organs and tissue.
Malignant Tumors - abnormal cells with the ability to invade nearby tissue and migrate to other parts of the body. (Cancerous Cells)
