Receptors & Receptor Binding

Question 1

Ligands that bind to the effector site on a receptor and activate it

Answer 1

Agonists

Question 2

Full Agonists

Answer 2

Fully activate receptor

Question 3

Partial Agonists

Answer 3

Cause partial activation of receptors

Question 4

Inverse Agonists

Answer 4

Bind to the effector site but produce a response opposite to that of a normal agonist

Question 5

Ligands that bind to receptors but do not activate them

Answer 5

Antagonists

Question 6

Competitive Antagonists

Answer 6

Compete with agonists for the same binding site

Question 7

Noncompetitive Antagonists

Answer 7

Bind to the receptor at a different site than the agonist

Question 8

Suicide Antagonists

Answer 8

Bind irreversibly to a receptor and remains bound for the rest of that receptor’s lifetime

Question 9

Modulators

Answer 9

Alter the affinity and/or efficacy of a drug

Question 10

Total Ligands [L] is equal to

Answer 10

amount of free ligands [F] + amount of bound ligands [B]

[L] = [F] + [B]

Question 11

Association Constant

Answer 11

Ka; the rate at which a ligand becomes bound to a receptor

Question 12

Dissociation Constant

Answer 12

Kd; the rate at which a ligand becomes unbound from a receptor

Question 13

Modulating the affinity of a drug will affect the _______ of the drug.

Answer 13

Efficacy

Question 14

Bmax

Answer 14

The maximum number of sites a specific ligand can bind to; equivalent to the number of free receptors [R] + ligand-receptor complex [B]

Question 15

Dose-Response Curves

Answer 15

Concentration of drug (x) vs. efficacy (y)

Question 16

Affinity

Answer 16

Likelihood of drug will blind to a receptor (inverse of Kd)

Question 17

Tolerance shifts the dose-response curves to the ______.

Answer 17

Right

Question 18

Sensitization shifts the dose-response curve to the ______.

Answer 18

Left

Question 19

Time-dependent (kinetic) plots

Answer 19

Association, dissociation, and drug clearance plots are all time dependent plots

Question 20

Hill Coefficient

Answer 20

Number of binding sites per receptor for a receptor-ligand interaction (slope of hill plot)

Question 21

Saturation Curves

Answer 21

Show how much drug is needed to saturate a system

Question 22

Scatchard Plot Slope

Answer 22

Inverse of dissociation constant and affinity

Question 23

Scatchard plot x-intercept

Answer 23

Bmax

Question 24

What is the Hill coefficient of most ionotropic receptors?

Answer 24

2

Question 25

Ligands only have a biological effect after becoming a _______ .

Answer 25

Ligand-receptor complex