Apoptosis

Question 1

1)How do cancer cells evade apoptosis;

Answer 1

In normal cells there is a P-53 gene which is a tumour suppressor gene that activates apoptosis. In cancer cells there is a mutation in the p53 gene which means apoptosis is not activated causing the cancer cells to thrive.

Question 2

Purpose of apoptosis:

Answer 2

destroyCell infected by virus,cells is no longer needed, Mutations or cancer cells

To sculpt body into its final form- webbing between digits, eyelids and tadpole tails

Question 3

Problems with apoptosis:

Answer 3

-Rapid and irreversible, hence may remove healthy cells from the body

Question 4

When does apoptosis begin:

Answer 4

●Begins when a signal is received which activates caspase enzymes to cause cell death

Question 5

Cascape:

Answer 5

Is a signalling molecule that activates other caspases leading to apoptosis.

Question 6

MAJOR STEPS OF APOPTOSIS:

Answer 6

1.Caspase enzymes are activated
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2.Organelles begin to breakdown
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3.The cell and nucleus shrinks and chromatic condesnses●
4.Blebbing of the plasma membrane occurs forming apoptotic bodies
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5.Apoptotic bodies are engulfed by phagocytes (immune cells).

Question 7

2 pathways of apoptosis

Answer 7

mictohdonrial pathway
death receptor pathway

Question 8

Mitochondria(intrinsic) pathway-
Process:

Answer 8

When DNA is damaged (radiation), the mitochondria releases a protein known as cytochrome c

Cytochrome c binds with proteins in the cytosol to activate caspase enzymes

When caspases are active, apoptosis begins.

Question 9

Death receptor pathway what is

Answer 9

Signalling molecules called death ligands bind to death receptors on the plasma membrane, this causes capsace enxymes to become activated to start apoptosis

Question 10

What initiates apoptosis via the mitochondrial pathway?

Answer 10

DNA damage, UV radiation, hypoxia (lack of oxygen), viral infection act as stress signals for the cell to initiate apoptosis via the intrinsic pathway

Question 11

Differences between mitochondria and death receptor pathway:

Answer 11

Intrinsic pathway occurs due to stress signals inside the cell such as hypoxia and uv radiation whereas extrinsic pathway occurs due to external signals/death ligands

intrinsic pathway involves cytochrome c and apoptosome whereas extrinsic pathway does not

intrinsic pathway involves caspase 9 whereas extrinsic involves caspase 8

Question 12

SIMILARITIES BETWEEN BOTH THE mitochodniral and death receptor PATHWAYS

Answer 12

1. both result in apoptosis

both end up activating caspase 3

Question 13

How is apoptosis related to cancer?

Answer 13

Apotosiswill occur the cancer cell to destruct

Question 14

Inhibited apoptosis:

Answer 14

May result in unnecessary body parts after development eg. webbed feet and hands

Question 15

Excessive apoptosis:

Answer 15

may result in diseases and disorders such as Huntington’s disease, Alzheimer’s disease and Parkinson’s disease.

Question 16

What does apoptosis in neurons result in:

Answer 16

●Apoptosis in neurons resulting in changes in mood, difficulty in movement and decreased cognitive ability.

Question 17

What happens if DNA repair is not possible?

Answer 17

P-53 gene activates apoptosis

Question 18

Tumours and Cancer occur when?:

Answer 18

when damaged cells replicate exponentially. Apoptosis does not occur enough

Question 19

when are erros in tumours detected

Answer 19

the G1 and G2 checkpoint

Question 20

Decreased rate of apoptosis can result:

Answer 20

: tumours

Question 21

Types of tumours

Answer 21

Benign tumours:
slowing growing masses that arent spread to other tissues and orgnas

malignant tumours:
cells that have invaded nearby tiusse and ohter parts of the body. these are cancerous cells

Question 22

malignant tumours:

Answer 22

cells that have invaded nearby tiusse and ohter parts of the body. these are cancerous cells

Question 23

Benign tumours:

Answer 23

slowing growing masses that arent spread to other tissues and orgnas

Question 24

Characteristics of cancer cells:

Answer 24

-Able to invade and spread
-resist cell death
-good blood supply
-evade tumours suppressors such as p53 gene
-able to replicate(immortal)

Question 25

Necrosis and example of it

Answer 25

unregulated death of a cell due to injury

can spread to neihouring tissue and often reuslts in inflammation

the heart would be an example of necrosis

Question 26

FACTORS THAT IMPACT APOPTOSIS:

Answer 26

●Inherited genes –
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●Mutations in genes
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●Tumour supressing genes
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●Chemical factors – tobacco, air pollutants
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●Physical factors – x-rays, UV rays
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●Biological factors – viruses which cause cancer

Question 27

apoptosis and example

Answer 27

regulated/controlled programmed cell death

example would be apotposis removing flesh between webbed hands in the womb

Question 28

main reasons for apoptosis

Answer 28

cells that are damaged or defective (because they have become cancerous ro infceted by a virus) must be eliminateed.

During fetal development, aptosis scuplts the body from its tissues. eg. webbing between fingers is removed by aptopsos

Question 29

What are the two major stages of apoptosis and what dothey iinclude

Answer 29

initiation-involves intrinsic and extrinsic pathway
execution-
**list whathappens in apoptoisis

Question 30

what are cancer cells, how do they form and how do cancer cells spread

Answer 30

unspecalised cells that divide and grow rapidly unctrollable to form a tumour

cancer cells form to genetic changes when a normal cell is transformed into a malignant cell

cancer cells spread by dividing uncontrollably and spreading to surrounding tissues.

Question 31

An example of an essiental change that causes magliancy

Answer 31

failure in apoptosis

Question 32

a cell infected by a virus can be secreted by

Answer 32

apoptosis if a natural killer cell finds it early enough to destroy and necrosis if the cell goes unchecked for a while

Question 33

reason for a defect in p53 gene

Answer 33

a lack of cell sensitiviyt to trail

Question 34

apoptotic cells are characterised by and what occurs after apoptosis and what can a failure in apoptosis lead to

Answer 34

cell shrinkage, blebbing, condensation of chromatin and fragmentation of DNA nad nucleus

phagocytosis occurs after apoptosis

failure in apoptosis can lead to cancer

Question 35

differnece btween mitosis and apoptosis and After the initiation of apoptosis, caspases begin digesting what

Answer 35

mitosis is how cells are produced, whereas apoptosis is how cells are destroyed

after the intation of apoptosis, capscase begins digesting protein

Question 36

What happens when DNA is damaged by radiation

Answer 36

apoptosis

Question 37

signal transduction

Answer 37

the process of transferring a signal throughout an organism

Question 38

function of capscase 3

Answer 38

breaks down cytokseleton

Question 39

process death receptor pathway

Answer 39

Caspase enzymes are activated

Organelles begin to breakdown

The cell and nucleus shrinks

Blebbing of the plasma membrane occurs forming apoptotic bodies

Apoptotic bodies are engulfed by phagocytes (immune cell).

Question 40

2 main functions of apoptosis

Answer 40

to sculpt the body
destory cells that are damaged

Question 41

After caspase enzymes are activated, what happens

Answer 41

cell shrinks/collaspes
DNA condenses and fragments
Blebbing
apopotic bodies break away and phagocytosis occurs