Week 9 - Intro to pharmacology

Question 1

What is a drug

Answer 1

A chemical substance which when administered to a living organism produces a biological effect

Question 2

What additional components may drugs contain

Answer 2

Stabilisers or solvents

Question 3

What is an agonist

Answer 3

A compound that binds to and activates a receptor

Question 4

Antagonist

Answer 4

A compounds that binds to a receptor and reduces the effect of an agonist

Question 5

Partial agonist

Answer 5

A low efficacy agonist that is unable to elicit the maximal response from a receptor, irrespective of the concentration applied

Question 6

Efficacy

Answer 6

Measure of the magnitude of the cellular response produced when an agonist binds to a receptor

Question 7

Potency

Answer 7

A measure of the concentration of a drug at which it produces an effect of a given magnitude

Question 8

Specificity

Answer 8

A measure of the number of receptor sites that a given drug may bind to or the range of effects it may produce.

Question 9

Selectivity

Answer 9

The degree to which a drug binds to a given receptor site relative to other receptor sites (related to affinity)

Question 10

What are 4 of the most common drug targets

Answer 10

Receptors
Enzymes
Carrier molecules (transporters)
Ion channels

Question 11

What must be true of agonists and receptors that act on the same receptor

Answer 11

They must have similar chemical characteristics that make them have the same selectivity and different chemical characteristics that make them have different effects.

Question 12

What is affinity

Answer 12

A measure of the equilibrium constant of the reversible reaction between a drug and a receptor i.e if EC is high then high affinity, low=low

Question 13

What is the relationship between agonist concentration and receptor occupancy

Answer 13

Hyperbolic

Question 14

What can we use the hyperbolic curve to calculate

Answer 14

the half-maximal response, known as the EC50.

Question 15

What can we do to optimise the calculation of the EC50

Answer 15

Use a logarithmic agonist concentration

Question 16

What other characteristic is normally associated with potency

Answer 16

High affinity

Question 17

What are the two ways in which antagonists can work

Answer 17

Competitive - binding to the same site as the agonist and competes for binding. Can be overcome by increasing agonist concentration.

Non-competitive - binding to a different site which causes a conformation change in the receptor to restrict agonist binding. Cannot be overcome by increasing agonist concentration