Biochemical Signalling

Question 1

What are the steps of signalling?

Answer 1

Signal
Reception
Transduction
Response
Termination

Question 2

What is the purpose of hormones?

Answer 2

Change cellular activity to coordinate metabolic activities.

Question 3

Example of a top-down hormone?

Answer 3

adrenaline

Question 4

Example of a bottom-up hormone?

Answer 4

Ghrelin (signals hunger)

Question 5

What occurs during desensitization?

Answer 5

The receptor is moved from the cell surface or is blocked

Question 6

How do GPCRs work?

Answer 6

A ligand binds to it, causing a change in shape of the GPCR which activates the connected G protein. This leads to a cascade of activations that amplify the signal.

Question 7

In what order do PKA, GDP, cAMP, and adenylate cyclase “activate”?

Answer 7

GDP > adenylate cyclase > cAMP > PKA

Question 8

How does the activation of cAMP activate PKA?

Answer 8

When inactive it physically blocks C subunit, but is moved when active allowing C substrate to be free.

Question 9

What are two common types of GPCRs?

Answer 9

PLC and beta-adrenergic receptor

Question 10

What type of receptor is insulin receptor?

Answer 10

tyrosine kinase, EGF

Question 11

What do nuclear hormone receptors do?

Answer 11

Bind to DNA to regulate transcription of specific genes.