Excess 140

Question 1

Receptor concept

Answer 1

That drug molecules interact with certain body components constitutes the receptor concept. The latter was attributed to the work of Langley & Erhlich (late 1800-early 1900)

Question 2

Receptor

Answer 2

Drug-receptor interaction likened to “lock and key” model.
•Ligands are substances that interact at the receptor binding site; could be endogenous or exogenous.
•Receptors are macromolecular components of a cell with which a drug interacts to produce a response.

They are protein structures (simple and multiple protein subunits).

Question 3

Characteristics of receptors

Answer 3

Characteristics of Receptor:
* sensitivity
* specificity - a drug only binds to one single type of receptor and causes one single effect.
* selectivity – a drug binds to one or a few types of receptors with higher affinity than to other receptors.

Question 4

Molecules serving as Receptors

Answer 4

• enzymes
• membrane proteins (glycoproteins, lipoproteins)
• nucleic acid
• complex polysaccharide

Question 5

Drug receptor binding forces

Answer 5

Covalent bond: Strong and in many cases not reversible under biological conditions. E.g. several anticancer drugs, and organo-phosphate anticholinesterases.
Ionic bond: Weaker than covalent, but stronger than the others. Most drugs employ this type of binding force.
Hydrogen bond: Stronger than Van-der-Waals
Van-der-Waals

Ligands (drugs, hormones, neurotransmitters) bind to receptors.
Binding or interaction is by means of chemical bonds
Binding can be specific and reversible.