intro to pharmacology wk3

Question 1

what is a receptor?

Answer 1

A bio molecule they have to bind to to exert to biological function

Question 2

what is the receptor concept?

Answer 2

• drugs produce their effects by combining with specific receptor sites in cells
• their response is a function of the number of occupied receptors

Question 3

what is the lock and key hypothesis?

Answer 3

• the shape of the drug complements the shape of the receptor
• chemical specificity ~ specificity in the side of drug (chemically made)
• affinity : the binging strength of the drug receptor interaction or likelihood of binding
• drug needs to bind

Question 4

what is a drug receptor?

Answer 4

• anything that caused a physiological effect, when interacting with a drug is a receptor

Question 5

what is an agonist?

Answer 5

• when binding to a receptor caused something similar to biological effect
• bind to a receptor and produce a response
• possess affinity and efficacy
• endrogenous agonists : ACH, histamine, TNF
• A + R = AR = AR* (law of mass)

Question 6

what is an antagonist ?

Answer 6

• binds to a receptor but does not produce a response
• prevents agonist binding and so blocks response to agonist
• affinity but not efficacy
• can be competitive, irreversible (eg poisoning) or more

Question 7

what is potency?

Answer 7

a measure of drug activity - a highly potent drug is only required in small amounts

Question 8

what is quantitative pharmacology?

Answer 8

based on assumption that drugs act by entering into a simple chemical relation with certain receptors in cells and that there is a simple relation between the amount of drug fixed by these receptors and action produced

Question 9

what is the law of mass action?

Answer 9

dissociation constant = (agonist conc x receptor conc) / (receptors with agonist conc)

Question 10

what do you use with response vs concentration?

Answer 10

1. response ~ concentration of drug-receptor complexes

2. fixed number of receptors

Question 11

what does dissociation constant =

Answer 11

(agonist conc x receptor conc) / (receptors with agonist conc)

Question 12

dissociation constant equation + law ot mass action =

Answer 12

p = agonist concentration / dissociation constant + concentration of agonist

Question 13

what is EC50?

Answer 13

concentration required for 50% of the maximum response to drug

Question 14

what is KD?

Answer 14

measure of 50% strength of binding of ligand