cell death and apoptosis

Question 1

describe apoptosis, autophagy and necrsosis

Answer 1

1. apoptosis is programed death by suicide
2. catabolic process defined by canibolism where the cell eats itself to survive
3. necroses is premature death or accidental death

Question 2

what are some of the uses of Apoptosis?

Answer 2

tissue sculting durinf development

eliminating T and B cells after an infection has cleared

removing cells damaged by UV radiation to prevent cancer

Question 3

if a patient comes in with syndactyly, you can hypothesize this was due to a defect in

Answer 3

Apoptosis pathway

Question 4

what are some noticable morphological markers of apoptosis?

Answer 4

nuclear fragmentation but the cell membrane is intact. the cytoplasmic organelles should look disorganized. large clear vacuoles.

Question 5

what are some morphological markers under visualization

Answer 5

cell blebbing and cell shrinking

Question 6

how would you notice a cell undergoing apoptosis from a biochemistry standpoint?

Answer 6

during apoptosis, a protein called scramblase causes phosphotydal serine to flip from the lumen side to the cytosolic side. Tunnel assay also detects strand breaks with a high sensitivity. and DNA laddering

Question 7

how can DNA laddering tell you a cell is undergoing apoptosis?

Answer 7

because during apoptosis, caspases are activated. the job of a caspase is to cleave DNA so if you run a gel and get two different sizes of DNA that means caspases are activated and the cell is undergoing apoptosis

Question 8

what is the level at which extrinsic and intrinsic pathway of apoptosis meet?

Answer 8

they converge on the level of caspases

Question 9

so we know p53 is the trigger for intrinsic apoptosis but what is its job in an unstressed cell?

Answer 9

it is a transcription factor that regulates cell cycle and apoptosis. It is kept at a low level in a normal cell so it cant fuck shit up

Question 10

what is the function of the BCL2 family of proteins?

Answer 10

they regulate the integrity of the mitochondrial membrane

Question 11

which of the BCl2 familymembers are pro apoptosis and which are anti?

Answer 11

Bad and Bax, and Bak, and Bid are pro

BCL2, BCL and MCL2 are anti

Question 12

how does BCL actually prevent apoptosis?

Answer 12

the intrinsic pathway wants to release cytochrome C from the mitochondria. To do that they must dock their apoptotic proteins bid, bad, and bax on the mitochondria. to prevent this from happening Bcl family proteins dock in the spots on the mitochondria so the pro apoptotic proteins cannot

Question 13

how can increased BCl 2 be a bad thing?

Answer 13

apoptosis is natural so increased BCL2 will create a situation that you cannot kill any cells even ones that are old or damaged…they go on to cause cancer

Question 14

what is the difference in the caspases?

Answer 14

caspase 9- intrinsic

caspase 8 and 10 extrinsic

caspase 3,6,7 actually do the killing

Question 15

what are the steps to the extrinsic apoptotic pathway?

Answer 15

1. pro apoptotic ligand binds to and activates receptor DR4 and DR5
2. DR4 and 5 recruit FADD to bind to the lumen end
3. they recruit initiator caspases (for extrinsic is 8 and 10)
4. 8 and 10 are released into the cytoplasm to activate exceutioners 3,6,7

Question 16

what are the TNF family do?

Answer 16

there are a family of death receptors for the extrinsic apoptosis pathway

Question 17

what are the steps in autophagy

Answer 17

induction

autophagosome formation

autophagosome lysosome fusion

autophagosome breakdown

Question 18

what role does Mtor play in autophagy?

Answer 18

when youre full. Mtor shuts down autohagy process. Starvation shuts down MTOR so the cell can undergo autophagy

Question 19

morphological features of a cell undergoing necrosis

Answer 19

Cell swelling. Disruption of plasma membrane. Cell lyses. Release of intracellular components after plasma membrane ruptures

Question 20

look at this! maybe

Answer 20

a