U3 AOS2 P2 Signal Transduction & Apoptosis

Question 1

What is Signal Transduction?

Answer 1

Process of converting original stimulus into a response

Question 2

What are the 3 main steps of Signal Transduction?

Answer 2

1. Reception
2. Transduction
3. Cellular Response

Question 3

What does Reception involve?

Answer 3

The detection and reception of a signal molecule`

Question 4

What does the placement of the receptor of the signal molecule indicate about the chemical property of the signal molecule?

Answer 4

It indicates whether it is Hydrophobic or Hydrophilic

Question 5

What type of signal molecule is it if the receptor is on the surface of the Plasma Membrane?

Answer 5

The signal molecule is Hydrophilic and cannot diffuse through the Plasma Membrane

Question 6

What type of signal molecule is it if the receptor is inside the cell (nucleus or cytosol)?

Answer 6

The signal molecule is Hydrophobic and can easily diffuse through the Plasma Membrane

Question 7

What does Transduction involve?

Answer 7

Converting the signal into a form suitable to be relayed to a final destination

Question 8

What are 3 examples of Cellular Responses?

Answer 8

Gene Transcription, Enzyme Activation, Secretion of Signal Molecules

Question 9

What are Hydrophobic Signal Molecules made out of?

Answer 9

They are lipid-based (steroids)

Question 10

What are Hydrophilic Signal Molecules made out of?

Answer 10

They are peptide-based (proteins)

Question 11

What happens when a Hydrophilic molecule binds to the receptor on the Plasma Membrane?

Answer 11

The inner-surface of the Plasma Membrane changes shape, activating a secondary messenger molecule (enzyme), initiating transduction cascades.

Question 12

What is Apoptosis?

Answer 12

Process which is known as programmed cell death, where certain cells are killed on purpose.

Question 13

What 4 things are regulated by Apoptosis?

Answer 13

1) Cells at the end of their natural life
2) Cells infected with a virus
3) Cells with damaged DNA
4) Embryonic Development

Question 14

What re the 3 stages of Apoptosis?

Answer 14

1) Cells forms ‘blebs’
2) Create smaller vesicles called ‘Apoptotic Bodies’
3) WBCs engulf apoptotic boides via Phagocytosis

Question 15

What are the 2 different pathways for Apoptosis?

Answer 15

Intrinsic Pathway

Extrinsic Pathway

Question 16

What’s another name for the Intrinsic Pathway?

Answer 16

Mitochondrial Pathway

Question 17

What’s another name for the Extrinsic Pathway?

Answer 17

Death Receptor Pathway

Question 18

What are caspases?

Answer 18

They are a set of enzymes which act as the signal molecule for Apoptosis.

Question 19

Describe the process of the Intrinsic Pathway

Answer 19

The Mitochondria detect whether a cell is damaged and needs to die. Once it it detects damage, it releases a chemical known as Cytochrome C into the cytoplasm which trigger caspasese, causing Apoptosis.

Question 20

Describe the process of the Extrinsic Pathway

Answer 20

Transmembrane (Integral) Proteins, contain death receptors which are triggered once the signal molecule binds to it, activating caspases that cause Apoptosis.

Question 21

What is one consequence of Excessive Apoptosis?

Answer 21

Neurodegeneration in Alzheimer’s Disease
Parkinson’s Disease
Motor Neuron Disease

Question 22

What is one consequence of to little Apoptosis?

Answer 22

Cancer