Lecture #16 - G protein-coupled receptors

Question 1

Why are G protein coupled receptors important? (3)

Answer 1

-

Question 2

What are G protein coupled receptors? (your version and their version)

Answer 2

It is a receptor found in the cell membrane that is connected to a G-protein. The G protein is not attached to the receptor since the receptor is inactive.

Question 3

What happens once an agonist binds to the receptor?

Answer 3

Once an agonist binds to the receptor, the receptor gets activated. Then the G protein comes and binds to it and then the G-protein gets activated (I think it changes shape) and goes and finds enzymes and up regulates or down regulates their activity to produce a secondary messenger. The secondary messenger alter the biochemistry of the cell.

Question 4

What do second messengers do?

Answer 4

They change amount of calcium in the cell, protein phosphorylation (?), other. And calcium is important for release of neurotransmitters. Protein phosphorylation is important for all sorts of things (it basically activates proteins). Also G proteins interact with ligand-gates ion channels to change excitability (change level of Na+ and Cl-)

Question 5

1. What is the type of second messenger dependent on?
2. Example of second messenger?
3. What changes the biochemistry of the cell?

Answer 5

-

Question 6

1. What are GPCR also called?
2. Where are they found?
3. Effector?
4. Coupling?
5. Response time? Why?
6. Example of GPCR?

Answer 6

-

Question 7

What would you discuss if you had to compare and contrast the ligand-gated ion channels and the GPCR?

Answer 7

1. Names
2. Location same (cell membrane)
3. Effector = enzyme/channel vs channel
4. Coupling = G protein (indirect) and direct for ligand
5. Response time (longer for GPCR because….)

Question 8

1. What is an example of a GPCR and what thing activates it?
2. What is Parkinson’s disease? Well, what results in it? (low levels of….)
3. What is used to treat activation? Give e.g.
4. Parkinson’s disease - neurodegenerative disorder and characterised by what 4 things?

Answer 8

-

Question 9

What is there a loss of in Parkinson’s patients?

Answer 9

-

Question 10

In parkinson’s patients:

1. Loss of…..
2. No… (so what does Levodopa do?)
3. No _____ ______ activation
4. What happens to 2nd messenger?

Answer 10

-

Question 11

What are the problems with Levodopa (what do you get with chronic treatment)?

Answer 11

-

Question 12

Why would you use an antagonist?

Answer 12

-

Question 13

Explain the anti psychosis thing

Answer 13

-