Drug Targets

Question 1

Pharmacodynamics

Answer 1

The physiological effect that a drug has on the body

Question 2

Pharmacokinetics

Answer 2

The metabolism of a drug by the body

Question 3

What are drugs?

Answer 3

A drug is a molecule that is applied to a physiological system to alleviate symptoms

Edible/ natural components are NOT drugs

Question 4

Therapy

Answer 4

A therapy treats the cause of a condition to alleviate symptoms, but it does not rectify the underlying physiological cause of the disease

Question 5

Cure

Answer 5

A cure removes the underlying cause of a disease

Question 6

Drug development process

Answer 6

The drug discovery process can take around 15 years

1. A chemist synthesises a variety of molecules specific to a receptor
2. Lead optimisation chooses the best of these molecules based on the efficacy and interaction of the drug in cell lines
3. Pre-phase I studies examine the pharmacokinetics in animal models
4. Clinical trails phases I-III progress the drug into humans
5. FDA approval

Question 7

Drug targets

Answer 7

Drugs can bind to biological molecules such as lipids, nucleic acids and proteins

The majority of drugs bind to proteins, specifically receptors

Question 8

Ion channel coupled receptors

Answer 8

Quaternary proteins (5-7 subunits)

When a ligand binds to the receptor it causes a conformational change, opening the channel

The molecule/ion allowed through the pore is dependent on size and charge

Question 9

GPCRs

Answer 9

GPCRs are very common drug targets

Single polypeptide with 7 transmembrane domains

The cytosolic side is associated with a G protein

The G protein fully associates with the receptor when a ligand activates the receptor, this leads to downstream signalling via secondary messenger systems

Question 10

Enzyme coupled receptors

Answer 10

Transmembrane proteins with a cytosolic side (kinase domain) and extracellular side (ligand-binding site)

Exist a monomers but the binding of a ligand causes dimerisation

Question 11

Nuclear receptors

Answer 11

Exist in the cytosol bound to a repressor protein

Binding of the ligand displaces the repressor and the complex is translocated to the nucleus, where it can interact with DNA to influence gene expression

Question 12

Agonist

Answer 12

Binds to and activates receptors

Question 13

Antagonist

Answer 13

Binds to receptors, having no effect

Sometimes called blockers

Question 14

Inverse agonist

Answer 14

Binds to receptors and causes an action opposite of the normal function of that receptor

Question 15

Blocker

Answer 15

Binds to ion channels and blocks movement of ions through the pore

Question 16

Modulator

Answer 16

Binds to ion channels, altering the sensitivity of the channel

Question 17

Inhibitors

Answer 17

Bind to and block the active site of an enzyme

Question 18

False substrate

Answer 18

Has a similar structure to the endogenous substrate and so is able to bind the endogenous substrate, but produces an abnormal metabolite

Question 19

Prodrug

Answer 19

Uses the enzyme to make itself active