BioSci107 Cell Communication

Question 1

What are the 3 main steps to cell signalling.

Answer 1

1.) RECEPTION
2.) TRANSDUCTION
3.) RESPONSE
(In order)

Question 2

What is a G protein coupled receptor shaped like and how many interactions sites does it have.

Answer 2

G-protein coupled receptors are transmembrane proteins which shaped like springs with 7 total coils.

They have two interaction sites one for the ligand (Signalling molecule) and the other for the GPD which binds to it from the cytoplasm.

Question 3

What are the molecules switch’s for a G-protein and which one is responsible for it being active and inactive.

Answer 3

G-proteins have 2 switch’s known as GTP (Guanosine triphosphate) and GDP (Guanosine diphosphate)

GTP = ACTIVE
GDP = INACTIVE

Question 4

What is the difference between a secondary and primary messenger.

(In cell signalling)

Answer 4

Primary messenger is a messenger from outside the cell and secondary messenger is a messenger from inside the cell.

Question 5

What are the steps which phosphorylation cascade occurs in.

Answer 5

1.) Inactive protein kinase —> Active protein kinase.
2.) ATP —> ADP (Energy is released)
3.) phosphate group is removed causing the active protein kinase to become inactive.

Question 6

What does a activated adenyl Cyclase do.

Answer 6

It’s converts ATP to cAMP

Question 7

What is the function of cAMP in cell signalling.

Answer 7

cAMP is a secondary messenger which regulates cell growth, gene transduction and protein expression

Question 8

What two areas in the cell have high calcium concentration.

Answer 8

Endoplasmic reticulum and matrix of the mitochondria.