Apoptosis Flashcards
1
Q
What is apoptosis
A
Programmed cell death in development
2
Q
Explain hayflick constant
A
Cells undergo around 50 mitotic divisions before apoptosis
3
Q
Describe the sequence of apoptosis
A
Enzymes break down cell cytoplasm Cytoplasm becomes dense Organelles are tightly packed Cell-surface changes and blebs form Chromatin condenses and the nuclear envelope breaks Cell breaks into vesicles Phagocytosis
4
Q
What enzymes control apoptosis
A
Degradation enzymes: caspases
5
Q
What can occur due to overactive and underactive caspases
A
Overactive: neurodegenerative disease
Underactive: tumour development
6
Q
Features of apoptosis
A
Regulated by organism Breaks down dna Breaks down nuclear membrane Cell membrane does not disintegrate May be single cells аffected Requires atp Ingested by neighbouring cells or phagocytes No leakage of cell contents Cell fragments into smaller bodies
7
Q
Features of necrosis
A
Not regulated by organism DNA is only broken down after cell has lysed Cell membrane disintegrates Nuclear membrane doesn’t get broken down No energy required (passive) Usually affects sheets of cells Ingested by phagocytes Leakage of cell contents End point is lysis of whole cell
