PATH201 Final Exam 2018 (tbc)

Question 1

What are the two types of cell death?

Answer 1

Necrosis and Apoptosis

Question 2

What is apoptosis?

Answer 2

Cell suicide

Question 3

What is apoptosis in response to?

Answer 3

Physiological conditions or pathological conditions

Question 4

When is physiological apoptosis used?

Answer 4

Physiological apoptosis is important for cell removal during embryogenesis, hormone dependent involution, cell death via immune system, and the removal of damaged cells during normal cell division.

Question 5

When is pathological apoptosis used?

Answer 5

pathological apoptosis can occur after some forms of cell injury, in particular DNA and protein damage

Question 6

What are the steps of apoptosis?

Answer 6

Cell shrinkage
Formation of cytoplasmic blebs
Formation of apoptotic bodies
Removal of apoptotic bodies

Question 7

What happens during cell shrinkage in apoptosis?

Answer 7

Microvilli contraction
Breaking of intercellular junctions
Condensing of chromatin

Question 8

What are the apoptotic bodies phagocytosed by?

Answer 8

Neighbouring cells or roving macrophages

Question 9

What are the features of apoptosis?

Answer 9

Shrunken cell
Intact membrane
No inflammatory response
Single cell affected
Active cellular death

Question 10

What is necrosis in response to?

Answer 10

Irreversible cellular stress

Question 11

What is necrosis?

Answer 11

Cell homicide via enzyme digestion

Question 12

How can enzyme digestion occur in necrosis?

Answer 12

autolysis or heterolysis

Question 13

What cellular changes mark the beginning of necrosis?

Answer 13

Swelling
Chromatin condense
Compromised membrane
Fluid rushing in

Question 14

What are the stages of necrosis?

Answer 14

Dissolution of cellular structures
Lysis
- Invasion of phagocytic cells
Inflammation

Question 15

Why is inflammation important in necrosis?

Answer 15

The inflammatory response is what ultimately leads to the clearing of necrotic material and healing after necrosis.

Question 16

What are the features of necrosis?

Answer 16

Passive cell death
Increased cell size
Disrupted membrane
Inflammatory response
Adjacent cells affected

Question 17

What are the apoptotic pathways?

Answer 17

Extrinsic (death receptor)
Intrinsic (mitochondrial)

Question 18

What allows extrinsic apoptosis to occur?

Answer 18

Receptor-ligand interactions

Question 19

When is intrinsic apoptosis used?

Answer 19

In response to cell injury such as DNA damage

Question 20

What is the function of cell checkpoints?

Answer 20

Checkpoints ensure that the cell cycle can proceed without errors.

Question 21

When can DNA damage occur?

Answer 21

DNA damage is an error that can occur during the cell cycle which can be caused by radiation, toxins, and free radicals.

Question 22

What can happen if DNA damage is unchecked?

Answer 22

Cell can accumulate in G1

Question 23

What is activated in response to DNA damage and how?

Answer 23

Activation of proapoptotic proteins by BH3-only sensors

Question 24

What happens in repsonse to proapoptotic protein activation?

Answer 24

Increase in mitochondria permeability from Bcl-2 family members (Bax and Bak)

Question 25

What happens when cytochrome c enters the cytoplasm?

Answer 25

Caspase activation

Question 26

What are caspases?

Answer 26

Caspases are specialised proteases that mediate both pathways of apoptosis

Question 27

How are caspases activated?

Answer 27

Whilst inactive caspases are dimerised. This means that when cleaved, the caspases become activated