Drug Targets

Question 1

Drug target

Answer 1

Molecules or structures that drugs interact with

Question 2

Examples of drug targets

Answer 2

Receptors
Enzymes
Ion channels
Transporters
Nucleic acids and the ribosome
Targets of monoclonal antibodies
Physicochemical mechanism

Question 3

Agonists

Answer 3

More of the effects

Question 4

Antagonist

Answer 4

Less of an effect

Question 5

Orlistat enzyme

Answer 5

Reversible covalent inhibitor of lipases
Reacts with a Ser residue in the lipase active site
Absorption of the free fatty acids is reduced
Reduce weight

Question 6

GABA receptors

Answer 6

Flow of chlorine ions which leads to hyper polarisation
Inhibitory neurotransmitter (sedative effect)

Question 7

DNA intercalators

Answer 7

Inset themselves between the DNA bases
Flat structure

Question 8

Doxorubicin

Answer 8

Intercalator which stabilises the DNA to topoisomerase II complex
Prevents topoisomerase release, cell unable to replicate or repair DNA damage, cell death

Question 9

Tubulin polymerises

Answer 9

Form microtubules which is essential for separation of sister chromatids in cell division

Question 11

How does a drug acting at b adrenergic receptors used to treat angina

Answer 11

Bonds to receptors but does not activate it
Blocks adrenaline which reduces rate and force of contraction of heart muscle
Reduces the downstream cAMP signalling from the receptor
Reduces symptoms of angina

Question 12

Explain how the interaction of orlistat with its target results in the observed pharmacological effects

Answer 12

Used to treat obesity
Covalent reversible inhibitor
Breaks down triacylglycerols into free fatty acids
Reacts with Ser residue and prevents lipase from binding
Reduces absorption of fatty acids
Weight loss

Question 13

Anxiolytic effect of benzodiazepines

Answer 13

Positive allosteric modulators of GABA receptor
Conformational change
Channel opens and flow of chloride ions into cell
Hyperpolarisation
Sedative effect

Question 14

Explain how a dna intercalator can be used to treat cancer

Answer 14

Insert themselves between bases in DNA
Doxorubicin
Stabilises the complex formed between the DNA and topoisomerase II (used in dna replication and transcription)
Formation of this complex stops cell replication and leads to cell death

Question 15

Give an example of a drug acting by a Physicochemical mechanism and explain how the drug results in the observed pharmacological effect

Answer 15

Activated charcoal
Treat poisoning
Adsorption of the poison onto the surface of the charcoal
Prevents poison from being further absorbed into blood