MSN 672 MODULE 3 ACTUAL PAPER 2026
QUESTIONS WITH SOLUTIONS GRADED A+
◉ Voltage-sensitive ion channels.
Answer: Activated by changes in membrane voltage or charge.
◉ Ionotropic receptors.
Answer: Another name for ligand-gated ion channels.
◉ Clinical relevance of ligand-gated vs voltage-sensitive channels.
Answer: LGICs → rapid effects (e.g., benzodiazepines, ketamine);
VSSCs/VSCCs → anticonvulsants, mood stabilizers, analgesics.
◉ Dual role of ligand-gated ion channels.
Answer: They act as both receptors and ion channels.
◉ Structure of LGICs.
Answer: Several subunits arranged around an ion channel with
binding sites for NTs, drugs, ions, and allosteric modulators.
, ◉ Pentameric receptors.
Answer: Receptors with 5 subunits.
◉ Tetrameric receptors.
Answer: Receptors with 4 subunits + re-entrant loop.
◉ Examples of pentameric receptors.
Answer: GABAA_AA, Nicotinic acetylcholine receptor (nAChR), 5-
HT3, Glycine receptor.
◉ Examples of tetrameric receptors.
Answer: AMPA, NMDA, Kainate (glutamate receptors).
◉ Pentameric LGIC subtypes.
Answer: GABAA_AA, nAChR, 5-HT3, Glycine receptors.
◉ Tetrameric LGIC subtypes.
Answer: AMPA, Kainate, NMDA.
◉ Assembly of pentameric receptors.
Answer: 5 subunits form a functional ion channel; subunit
composition defines receptor subtype.
QUESTIONS WITH SOLUTIONS GRADED A+
◉ Voltage-sensitive ion channels.
Answer: Activated by changes in membrane voltage or charge.
◉ Ionotropic receptors.
Answer: Another name for ligand-gated ion channels.
◉ Clinical relevance of ligand-gated vs voltage-sensitive channels.
Answer: LGICs → rapid effects (e.g., benzodiazepines, ketamine);
VSSCs/VSCCs → anticonvulsants, mood stabilizers, analgesics.
◉ Dual role of ligand-gated ion channels.
Answer: They act as both receptors and ion channels.
◉ Structure of LGICs.
Answer: Several subunits arranged around an ion channel with
binding sites for NTs, drugs, ions, and allosteric modulators.
, ◉ Pentameric receptors.
Answer: Receptors with 5 subunits.
◉ Tetrameric receptors.
Answer: Receptors with 4 subunits + re-entrant loop.
◉ Examples of pentameric receptors.
Answer: GABAA_AA, Nicotinic acetylcholine receptor (nAChR), 5-
HT3, Glycine receptor.
◉ Examples of tetrameric receptors.
Answer: AMPA, NMDA, Kainate (glutamate receptors).
◉ Pentameric LGIC subtypes.
Answer: GABAA_AA, nAChR, 5-HT3, Glycine receptors.
◉ Tetrameric LGIC subtypes.
Answer: AMPA, Kainate, NMDA.
◉ Assembly of pentameric receptors.
Answer: 5 subunits form a functional ion channel; subunit
composition defines receptor subtype.
