MCQ: Pharmacodynamics

Question 1

What consists a G-coupled receptor?

Answer 1

A, B and G subunits.

Question 2

cAMP is a hydrophobic or hydrophilic molecule?

Answer 2

cAMP is a hydrophilic

Question 3

Examples of G-coupled receptors?

Answer 3

Opioid receptors

B-adrenergic

Question 4

What acts at tyrosine kinase receptors?

Answer 4

Insulin

Growth factor

Question 5

What acts at the cell surface receptor guanyl cyclase?

Answer 5

ANP

Nitric oxide

Question 6

Examples of mixed agonist-antagonists

Answer 6

Opioids (Pentazocine, Nalbuphine and Buprenorphine), Mirtazepine,
Pindolol
Xameterol.

Question 7

Define half life

Answer 7

0.693 x time constant

Time taken in an exponential process for the value to decrease by half (t 1/2)

Question 8

What is the time constant?

Answer 8

1. The time taken for an exponential process to complete if it continued at its initial rate of decay.
2. Time for value to fall by 2/3.
3. The time constant is the RECIPROCAL of the rate constant.

Question 9

components of Ach receptor

Answer 9

The adult acetylcholine receptor has:

• 2 x A subunits (to which acetylcholine binds),
• B subunit,
• D subunit
• episilon subunit (this is replaced by a gamma subunit in the foetus).

Question 10

What type of receptors reduce cAMP?

Answer 10

Gi type g-protein coupled receptors and when stimulated decrease cAMP

Question 11

Is the time constant longer than the half life?

Answer 11

Yes it is.

An exponential process is said to be complete after 3 time constants, as opposed to 5 half-lives.