Intro to Receptor Function

Question 1

What is a receptor?

Answer 1

A macromolecular protein that recognises a ligand and transduces a signal into a cellular response

Question 2

What two key properties must receptors have?

Answer 2

Recognition and transduction

Question 3

What happens when a ligand binds a receptor?

Answer 3

It induces a conformational change that triggers signalling

Question 4

Why are receptors saturable?

Answer 4

There are a finite number of receptors

Question 5

What determines the strength of a receptor signal?

Answer 5

The proportion of receptors occupied by ligand

Question 6

What is receptor up-regulation?

Answer 6

Increase in receptor number

Question 7

What is receptor down-regulation?

Answer 7

Decrease in receptor number

Question 8

What factors determine hormone-receptor complex formation?

Answer 8

Hormone concentration, receptor concentration, and affinity

Question 9

What types of bonds are involved in ligand-receptor binding?

Answer 9

Non-covalent (hydrogen, electrostatic, hydrophobic, Van der Waals)

Question 10

What is an agonist?

Answer 10

A drug that activates a receptor to produce a response

Question 11

What is an antagonist?

Answer 11

A drug that blocks or reduces receptor activity

Question 12

How do drugs affect signalling?

Answer 12

They can enhance, reduce, or block generation or transmission

Question 13

Are most drug-receptor interactions reversible or irreversible?

Answer 13

Reversible

Question 14

Why are irreversible interactions often undesirable?

Answer 14

They can cause toxicity, mutagenicity, or carcinogenicity

Question 15

What are orthosteric drugs?

Answer 15

Drugs that bind to the same site as the natural ligand

Question 16

What are allosteric drugs?

Answer 16

Drugs that bind to a different site and modify receptor activity