Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/42

Click to flip

42 Cards in this Set

  • Front
  • Back
What is the difference between necrosis and apoptosis?
1.in necrosis the plasma membrane is ruptured and the contents of the cell spill out and cause inflammation;
2. necrosis is passive, apoptosis is active
Does the extrinsic apoptotic pathway converge with the intrinsic pathway before or after the level of mitochondria?
either
What cleaves essential proteins?
caspases
In apoptosis and necrosis, DNA is cleaved into ____ fragments.
200 bp
An example of a death receptor ligand
Fas
Fas binding induces...
receptor trimerization
example of an initiator caspase
caspase 8
example of an effector caspase
caspase 3
caspase 3 is recruited in an (active/inactive) state
inactive
brief overview of extrinsic pathway
Fas --> timerization --> FADD --> caspase 8 --> caspase 3 --> cleavage of proteins/DNA
what are some types of death receptors?
TNF, Fas, p75 NTR
Describe the domains of death receptors. What do they do?
Extracellular: cysteine rich
Cytoplasmic: death domain
They induce trimerization
Describe the intrinsic apoptotic pathway.
stimulus -->
intracellular stress signals -->
disrupts balance of pro to anti apoptotic Bcl-2 family members -->
mitochondrial stress -->
release of cytochrome C into cytosol -->
recruitment of adaptor protein (Apaf1) -->
recruits inactive caspase 9 -->
activates caspase 3 -->
cell death
What are pro-antipoptotic molecules? anti?
pro (Bax)
anti (Bcl-2 or Bcl-x)
What is in an apoptosome?
cytochrome C
caspase 9
Apaf1
dATP
What is Bcl-2?
a pro-survival oncogene from B-cell lymphoma
What are the two pro-apoptosis of the Bcl-2 family?
Bax and BH3 only
Describe what happens when the intrinsic and extrinsic pathways converge at before caspase 3?
1.activation of caspase 8 can cleave Bid --> tBid
2.tBid binds Bax at mitochondria
3.activates intrinsic pathway
What are caspases?
cysteine proteases that cleave after aspartate residues
Initiator caspases
2,8,9,10
Effector caspases
3,6,7
Cytokine activator caspases
1,4,5,12
What are initiator caspases?
latent monomers activated by their dimerization
What are effector caspases?
latent dimers activated by cleavage of their interdomain linker
______ _______ _______ are by definition active caspases.
Cleaved Effector Caspases
In the aging brain there is an increase/decrease in lysosome fxn.
decrease
T/F: a normal cell has autphagy occuring at a low level
True
The nucleus of an autophagic cell is ________ and _______
hyperchromatic (extremely dense)
fragmented
Characteristics of AD
amyloid plaques with dystrophic neurites
neurofibrillary tangles
5 groups of AD:
sporadic late onset
familial late onset
familial early onset
Assoc. w/ down syndrome
Assoc. w/ other neurodegen. disorder (parkinson's)
Macroscopic changes in AD brain:
dec brain weight
widening of sulci
narrowing of gyri
dec white matter
What regions are primarly affected in AD?
hippocampus and cortex
Primary neurochemical effects:
loss of Ach
loss of cholinergic pre-synaptic markers (ex. nicotinic receptors)
Secondary neurochemical effects:
loss of GABAergic cortical neruons
loss of 5-HT and adrenergic input to cortex from other areas
Microscopic changes in AD:
extracellular amyloid plaques
neurfibrillary tangles
dystrophic neuritis
massive loss of cortical synapses and neurons
inc in undigested lipopigment
inc. in number of autophagosomes
What makes up neurofibrillary tangles?
hyperphosphorylated tau
What forms amyloid beta plaques?
amyloid precursor protein
How does the APP pathway work normally?
APP is cleaved by alpha-secretase preventing formation of amyloid beta
What happens to APP pathway in AD brain?
APP is cleaved by beta-secretase or gamma-secretase and creates amyloid beta peptide which aggregates to form plaques
Hypothetical Amyloid Cascade model of AD
1.APP cleaved by beta and gamma secretases to form AB
2.AB fibrillates and forms plaques
3.AB can activate microglia causing an inflamm. response around plaque
4.activated microglia cause cell death response
5. AB reacts with neuron causing dystrophic neuritis
In AD there is extensive ______ ______ and _____ _____.
neuron death
synapse loss
AD has (acute/chronic) onset and progression.
chronic