Chapter 18: Cell death and renewal Flashcards
1
Q
How many cells are eliminated daily by programmed cell death?
A
5 X 1011
2
Q
2 types of cell death
A
apoptosis and necrosis
3
Q
What are caspases?
A
- proteases with cystein residues at active sites that cleave after aspartic acid
- executioners of programmed cell death
4
Q
Targets of caspases?
A
- inhibitor of DNase
- nuclear lamins
- cytoskeletal proteins
- golgi matrix proteins
- scramblase
5
Q
What is IAP?
A
- inhibitor of apoptosis
- regulates caspases
- suppresses apoptosis
6
Q
Formation of apoptosome?
A
complex of caspase-9 and APAF-1 requiring cytochrome c
7
Q
What stimulates the release of cytochrome c from mitochondrial membranes to cytosol?
A
active Bak/Bax
8
Q
Intrinsic pathway activated by?
A
DNA damage and lack of growth factors
9
Q
Extrinsic pathway activated by?
A
signals from other cells
10
Q
p53 mediation of cell cycle arrest and DNA damage
A
- activation of p53
- increased expression of PUMA and NOXA
- activation of Bak and Bax
- release of cytochrome c
- activation of caspase-9
11
Q
Function of PI-3 kinase?
A
promotes cell survival
12
Q
Autophagy
A
Gradual turnover of cell’s components by uptake of proteins or organelles into vesicles that fuse w lysosomes
