Exam 4 part 3 Flashcards
morphological changes in apoptotic cells
- cell shrinks
- cytoskeleton collapses
- nuclear envelope disassembles
- Chromatin condenses, then break into pieces
- cell surface forms enclosed apoptotic bodies
- apoptotic bodies absorbed by cells or macrophages
apoptosis
programmed cell death
necrosis
accidental cell death
cell swells and bursts spilling contents
TUNEL assay
Txt-mediated dUTP Nick End Labeling
Detection of Annexing V
- changes in membrane during apoptosis\
- phospholipid phophatidylserine flips to outer surface
- Annexin V binds to phosphatidylserine
Annexin V purposes
- Marker
- “eat me” signal to macrophages
- blocks inflammation
two major pathways of apoptosis
intrinsic pathway- trigger from inside cell
extrinsic pathway- triggered from outside by ligand
caspases
- intracellular enzymes that trigger cell death
- cysteine at active site
- cleave aspartic acids
inactive precursor to caspase
procaspase
first caspase activated
initiator caspase
activates other procaspases
these new ones are executioner caspases
activate the extrinsic pathway of apoptosis
cell-surface death receptors
these receptors are from the TNF family
FADD
Fas-associated death domain
on killer lymphocyte
DISC
Death-inducing signaling complex
Cytochrome C
- component of mitochondria ETC
- binds to procaspase activating protein Apaf1
- Apaf1 form a wheel heptameter called apoptosome
- activates caspase-9, which activates executioner caspases
anti-apoptotic Bcl2 family protein
when active, keeps Bcl2 family proteins apart so they can’t form a pore in the mitochondria
