M&R Drugs And Receptors

Question 0

What is the most critical factor in determining drug action?

Answer 0

Concentration or drug molecules around a receptor

Question 1

How do drugs exert their effect?

Answer 1

By binding to a target (mostly proteins)

Question 2

How do you work out molarity?

Answer 2

Mwt

Question 3

What is the binding of the ligand determined by?

Answer 3

Affinity of the ligand and receptors

Question 4

What is the receptor activation governed by?

Answer 4

Intrinsic efficacy

Question 5

What is the difference between intrinsic efficacy and efficacy?

Answer 5

Intrinsic efficacy is the ability to activate a receptor ligand complex whilst efficacy is the ability to generate a response

Question 6

What do antagonists do?

Answer 6

They prevent the binding of agonists by blocking the sites

Question 7

What is B max?

Answer 7

The maximum binding capacity of receptors

Question 8

What is Kd?

Answer 8

The measure of affinity

The concentration of ligand required to occupy 50% of available receptors

Question 9

What does a low Kd mean?

Answer 9

There is a high affinity for ligands (lower drug conc needed for 50% binding)

Question 10

What are the scale of most drug graphs?

Answer 10

Logarithmic

Question 11

What is the shape of the logarithmic curve?

Answer 11

Sigmoidal

Question 12

What does the concentration response curve show?

Answer 12

The EC50 - gives 50% of max response

This is a measure of potency - affinity + efficacy

Question 13

How does salbutamol ensure only B2 receptors are stimulated?

Answer 13

B2 selective efficacy

Question 14

How does salmeterol ensure B2 stimulation?

Answer 14

Selective based on affinity

Question 15

Why can there be not all receptors binded but still 100% response?

Answer 15

Spare receptors

Question 16

Why do spare receptors exist?

Answer 16

Amplification in signal transduction

So few moles needed to impact whole cell response

Question 17

How does spare receptors allow for increased sensitivity?

Answer 17

If 50% occupancy gives full response then the cell is more suspectible to full response with a lower conc of drug

Question 18

What does changing the receptor number do?

Answer 18

Changes agonist potency and can effect the maximal response

Question 19

Are receptor numbers fixed?

Answer 19

No, they can be up regulated or down regulated depending on what is required.

Question 20

What are partial agonists?

Answer 20

Turns receptor on a bit, even with 100% receptor filled gamy get a full response

Question 21

What are the 3 mechanisms of antagonists?

Answer 21

Reversible competitive
Irreversible competitive
Non competitive