Chapter 23 - Cell Death

Question 1

Physiological process - Cell death

Answer 1

Apoptosis

Question 2

The difference between necrosis and apoptosis is;

Answer 2

• Necrosis is passive and damage neighbouring cells. Necrosis is caused by injury or disease -> NOT programmed cell death
• Apoptosis is an active process where no neighbouring cells are damaged. Apoptosis is programmed cell death.

Question 3

What enzymes is used to generate ATP from glucose?

Answer 3

Lactate dehydrogenase (LDH)

Question 4

Which enzyme is used for a general marker for necrotic cell death?

Answer 4

Lactate dehydrogenase (LDH)

Question 5

What does the mitochondria of apoptopic cells release?

Answer 5

Cytochrome c

Question 6

What happens with chromatin of apoptotic cells?

Answer 6

Segments and condence

Question 7

Apoptotic cells are engulfed by;

Answer 7

• phagocytic cells
• macrophages
• dendritic cells

Question 8

What cytokines are released by phagocytic cells that reduce the risk of inflammation from the cell death?

Answer 8

• Interleukin-10 (IL-10)

- Transforming growth factor- “Beta” (TGF-“beta”)

Question 9

What does p53 do with a damaged cell?

Answer 9

P53 halt the cell cycle and stimulate apoptosis

Question 10

What triggers programmed cell death?

Answer 10

The normal p53 binds to a p53-responsive element within the gene promoter of the proapoptotic protein Bax.

Question 11

What happens if we have an abdnormal p53?

Answer 11

The Bax is not produced which means that the cell continues to survive and divide => it does not undergo apoptosis

Question 12

Sonic hedgehog and apoptosis

Answer 12

During the embryonic development Shh has to attach to Patched 1(Ptc1) in order for the target cell to survive. If the Shh does not bind to Ptc then the target cell dies by undergoing apoptosis

Question 13

Hemostasis

Answer 13

Is a balance between the cell death and proliferation

Question 14

Cell death

Answer 14

• apoptosis

- necrosis

Question 15

Cell proloferation

Answer 15

• cell replacement

- cell growth

Question 16

Apoptosome

Answer 16

A large protein complex that requires ATP for its formation.

Internal cell death program

Question 17

What triggers apoptosome?

Answer 17

Cytochrome c in the cytoplasm

Question 18

Bax

Answer 18

• A proapoptotic protein

- Form a channel on the mitochondria which allows the cytochrom c to exit ->triggers the formation of apoptosome

Question 19

What happens with the cytochrome c when it is in the cytoplasm?

Answer 19

• cytochrome c activates Apaf-1 adaptor protein
• Apaf-1 adaptor protein activates caspase 9 of the caspase proteolytic cascade that will cleave and destroy cellular proteins and DNA in order to cause cell death by apoptosis

Question 20

What initiates apoptosis from external signals?

Answer 20

Death receptors belonging to the Tumour Necrosis Factor Receptor(TNFR) gene superfamily

Question 21

What is the homologous cytoplasmic sequence possessed by those TNF members that do initoate cell death termed?

Answer 21

Death domain (DD)

Question 22

Give examples of adaptor molecules that do contain DDs (death domains)?

Answer 22

• FADD (Fas-associated death domain)
• ## TRADD (TNFR-associated protein)The interact with the death receptors to transmit the apoptotic signal to death machinery, via activation of caspase 8 or 10

Question 23

Pathological process - cell death

Answer 23

Necrosis