Ch 16 Apoptosis

Question 1

Define: Apoptosis

Answer 1

Programed Cell death

Question 2

What features appear in apoptosis that DOESN’T in Necrosis

Answer 2

Cell and Nucleus fragments.

Question 3

How are initiator caspases activated

Answer 3

Cleavage onto death receptor domain & oligerimization

Question 4

How does XIAP inhibit caspases

Answer 4

Binding to caspase changes its conformation and by using E3 ubiquitin ligase.

Question 5

how are executioner caspases activated

Answer 5

by binding to and rearanging initiator caspase

Question 6

WHich events does take place during the death receptor pathway of the tumor necrosis factor receptor (TNFR1) signaling?

Answer 6

TNFR1 ligases with TNF requiring RIPK1 and RIPK3

Question 7

What is the complex found in the mitochondria that drives apoptosis?

Answer 7

Chromosome complex

Question 8

Explain how activation of tumor necrosis factor (TNFR1) can induce antiapoptotic signals?

Answer 8

Complex 1 of TNF tries to repair cell, Complex 2 causes death.

Question 9

What is the functional role of CARD domains

Answer 9

Protein to protein
Inflammation
Cell signaling

Question 10

MOMP, mitochondrial outer membrane permeabilization is a key event in apoptosis. What role do the apoptotic BCL-2 proteins Bax and Bak play in MOMP?

Answer 10

Form dimer to induce mitochondrial polymerization.

Question 11

During mitochondrial outer membrane permeabilization (MOMP) what is allowed to escape from the citochondria

Answer 11

Cytochrome allowed by Bax

Question 12

What is a complex of multimers of APAF-1 doing?

Answer 12

Binds to procaspase 9 and forms apoptosome

begins cell degradation

Question 13

How is procaspase 9 induced

Answer 13

by binding to APAF1

Question 14

How are apoptotic cells completely removed from the tissue they reside in?

Answer 14

Macrophages and Phagocytes

Consumed by other cells

Question 15

Explain how death receptors activate initiator caspases,.

Answer 15

Relay aptopic signals by binding ligands to receptors

Question 16

What happens when cytochrome c binds to apaf1

Answer 16

activates and promotes apaf 1

Question 17

list the features of executioner caspases that distinguish them from other caspase types

Answer 17

have a small connection domain. This activates them by cleavage

Question 18

define: induced proximity

Answer 18

binding forces dimerization

Question 19

Example: Induced proximity

Answer 19

Initiator caspase and protein adapter

Question 20

Briefly explain how cytochrome c activates caspase 9

Answer 20

death signal to cytochrome c to binding APAF1 to activation of caspase 9

Question 21

explain how the protein bid links the death receptor pathway and MOMP pathway to apoptosis.

Answer 21

Because it is in a BCL2 family and can induce MOMP given ratios of proapoptosis and antiapoptosis

Question 22

Explain how a flippase enzyme assists in the clearance of apoptotic cells in mammals

Answer 22

Being located on the membrane, flippase produce signals for macrophages to recognize and eat.