4C. Apoptosis

Apoptosis

A controlled process of programmed cell death that removes damaged or unnecessary cells without causing inflammation.

Intrinsic Pathway

An apoptosis pathway triggered by internal cellular damage, such as DNA damage and oxidative stress.

Extrinsic Pathway

An apoptosis pathway triggered by external signals, where a ligand binds to death receptors on the plasma membrane.

Caspase Enzyme

A family of proteases that cleave intracellular components during apoptosis.

Cytochrome c

A protein in the inner mitochondrial membrane, released during apoptosis to trigger caspase activation.

Blebbing

The process where the plasma membrane bulges outward due to cytoskeleton breakdown, forming apoptotic bodies.

Apoptotic Bodies

Small membrane-bound vesicles containing fragmented cellular material, formed during apoptosis.

Phagocyte

An immune cell that engulfs and digests apoptotic bodies and cellular debris.

Phagocytosis

The process where a phagocyte engulfs solid material and digests it using lysosomes.

Ligand

A signaling molecule that binds to a receptor on a target cell, triggering a response.

Pro-apoptotic Protein

A protein that promotes apoptosis, often by triggering cytochrome c release from mitochondria.

Anti-apoptotic Protein

A protein that prevents apoptosis by blocking cytochrome c release and caspase activation.

Kinase

An enzyme that transfers phosphate groups to proteins, regulating many cellular processes.

Necrosis

A pathological form of cell death caused by injury or toxins, often leading to inflammation.

Tumour

A mass of abnormal cells arising from uncontrolled cell division.

Benign Tumour

A non-cancerous tumour that does not invade surrounding tissues.

Malignant Tumour

A cancerous tumour that can invade nearby tissues and metastasise.

Cancer

A disease caused by uncontrolled cell division and the ability of abnormal cells to invade tissues.

Metastasis

The spread of cancer cells from the primary tumour site to distant parts of the body.

Engulf

The process where a cell surrounds and takes in particles through phagocytosis.