1
NURS 5357 Neurobiology Exam 3 Actual
Exam 2026/2027 | Questions with Complete
Solutions | Course Blueprint Aligned | Pass
Guaranteed - A+ Graded
NURS 5357 NEUROBIOLOGY EXAM 3
SECTION 1: NEUROTRANSMITTERS & RECEPTOR SYSTEMS (15 Questions)
Q1: Which neurotransmitter is synthesized from tyrosine via the rate-limiting enzyme tyrosine
hydroxylase and is primarily degraded by monoamine oxidase (MAO) and catechol-O-
methyltransferase (COMT)?
A. Serotonin
B. Dopamine
C. Acetylcholine
D. GABA
Correct Answer: B. [CORRECT]
Rationale: Dopamine is synthesized from tyrosine via tyrosine hydroxylase (rate-limiting step)
and DOPA decarboxylase. It is metabolized by MAO (to DOPAC) and COMT (to 3-
methoxytyramine), ultimately forming homovanillic acid (HVA). This catecholamine pathway is
distinct from serotonin (tryptophan-derived), acetylcholine (choline + acetyl-CoA), and GABA
(glutamate-derived via GAD).
Q2: The ionotropic GABA-A receptor contains which of the following ion channels?
A. Chloride channel
B. Sodium channel
C. Potassium channel
D. Calcium channel
,2
Correct Answer: A. [CORRECT]
Rationale: GABA-A receptors are ligand-gated chloride channels. GABA binding triggers
chloride influx, causing hyperpolarization and neuronal inhibition. This chloride conductance is
potentiated by benzodiazepines and barbiturates at allosteric sites.
Q3: Which second messenger system is characteristically coupled to metabotropic glutamate
receptors (mGluRs)?
A. Direct ion channel gating
B. G-protein activation of phospholipase C or adenylyl cyclase
C. Tyrosine kinase receptor autophosphorylation
D. Nuclear receptor translocation
Correct Answer: B. [CORRECT]
Rationale: Metabotropic glutamate receptors are G-protein coupled receptors (GPCRs). Group I
mGluRs (mGluR1, mGluR5) activate Gq, stimulating phospholipase C → IP3/DAG → calcium
release. Group II/III mGluRs inhibit adenylyl cyclase via Gi/o coupling, reducing cAMP
formation.
Q4: Acetylcholine synthesis requires which essential precursor and enzyme combination?
A. Tyrosine + tyrosine hydroxylase
B. Tryptophan + tryptophan hydroxylase
C. Choline + choline acetyltransferase (ChAT)
D. Glutamate + glutamic acid decarboxylase
Correct Answer: C. [CORRECT]
Rationale: Acetylcholine is synthesized from choline and acetyl-CoA by choline
acetyltransferase (ChAT) in the cytoplasm of cholinergic neurons. Choline uptake via high-
affinity transporters (CHT1) is rate-limiting. Acetylcholine is degraded by acetylcholinesterase
(AChE) into choline and acetate.
SATA Question Q5: Which of the following are ionotropic glutamate receptors? Select all that
apply.
A. NMDA receptors
B. AMPA receptors
C. Kainate receptors
D. mGluR1
, 3
E. GABA-A receptors
F. Glycine receptors
Correct Answers: A, B, C. [CORRECT]
Rationale: Ionotropic glutamate receptors are ligand-gated ion channels comprising three
families: NMDA (N-methyl-D-aspartate), AMPA (α-amino-3-hydroxy-5-methyl-4-
isoxazolepropionic acid), and kainate receptors. These mediate fast excitatory neurotransmission.
mGluR1 is metabotropic (GPCR). GABA-A and glycine receptors are ionotropic but for
inhibitory neurotransmitters, not glutamate.
Q6: Which neurotransmitter is primarily synthesized in the raphe nuclei and projects diffusely
throughout the CNS to regulate mood, sleep, and appetite?
A. Dopamine
B. Norepinephrine
C. Serotonin (5-HT)
D. Histamine
Correct Answer: C. [CORRECT]
Rationale: Serotonergic neurons originate in the raphe nuclei (midline brainstem) and project
widely to cortex, limbic system, and spinal cord. Serotonin (5-hydroxytryptamine) is synthesized
from tryptophan via tryptophan hydroxylase (rate-limiting) and aromatic L-amino acid
decarboxylase. Raphe dysfunction is implicated in depression and anxiety disorders.
Q7: The co-agonist requirement for NMDA receptor activation includes which amino acid in
addition to glutamate?
A. GABA
B. Glycine
C. Dopamine
D. Serotonin
Correct Answer: B. [CORRECT]
Rationale: NMDA receptors require simultaneous binding of glutamate (agonist at GluN2
subunits) and glycine (co-agonist at GluN1 subunits) for channel opening. This dual requirement,
plus voltage-dependent magnesium block, makes NMDA receptors coincidence detectors critical
for synaptic plasticity and learning.
Q8: Which enzyme is responsible for the degradation of acetylcholine in the synaptic cleft?
NURS 5357 Neurobiology Exam 3 Actual
Exam 2026/2027 | Questions with Complete
Solutions | Course Blueprint Aligned | Pass
Guaranteed - A+ Graded
NURS 5357 NEUROBIOLOGY EXAM 3
SECTION 1: NEUROTRANSMITTERS & RECEPTOR SYSTEMS (15 Questions)
Q1: Which neurotransmitter is synthesized from tyrosine via the rate-limiting enzyme tyrosine
hydroxylase and is primarily degraded by monoamine oxidase (MAO) and catechol-O-
methyltransferase (COMT)?
A. Serotonin
B. Dopamine
C. Acetylcholine
D. GABA
Correct Answer: B. [CORRECT]
Rationale: Dopamine is synthesized from tyrosine via tyrosine hydroxylase (rate-limiting step)
and DOPA decarboxylase. It is metabolized by MAO (to DOPAC) and COMT (to 3-
methoxytyramine), ultimately forming homovanillic acid (HVA). This catecholamine pathway is
distinct from serotonin (tryptophan-derived), acetylcholine (choline + acetyl-CoA), and GABA
(glutamate-derived via GAD).
Q2: The ionotropic GABA-A receptor contains which of the following ion channels?
A. Chloride channel
B. Sodium channel
C. Potassium channel
D. Calcium channel
,2
Correct Answer: A. [CORRECT]
Rationale: GABA-A receptors are ligand-gated chloride channels. GABA binding triggers
chloride influx, causing hyperpolarization and neuronal inhibition. This chloride conductance is
potentiated by benzodiazepines and barbiturates at allosteric sites.
Q3: Which second messenger system is characteristically coupled to metabotropic glutamate
receptors (mGluRs)?
A. Direct ion channel gating
B. G-protein activation of phospholipase C or adenylyl cyclase
C. Tyrosine kinase receptor autophosphorylation
D. Nuclear receptor translocation
Correct Answer: B. [CORRECT]
Rationale: Metabotropic glutamate receptors are G-protein coupled receptors (GPCRs). Group I
mGluRs (mGluR1, mGluR5) activate Gq, stimulating phospholipase C → IP3/DAG → calcium
release. Group II/III mGluRs inhibit adenylyl cyclase via Gi/o coupling, reducing cAMP
formation.
Q4: Acetylcholine synthesis requires which essential precursor and enzyme combination?
A. Tyrosine + tyrosine hydroxylase
B. Tryptophan + tryptophan hydroxylase
C. Choline + choline acetyltransferase (ChAT)
D. Glutamate + glutamic acid decarboxylase
Correct Answer: C. [CORRECT]
Rationale: Acetylcholine is synthesized from choline and acetyl-CoA by choline
acetyltransferase (ChAT) in the cytoplasm of cholinergic neurons. Choline uptake via high-
affinity transporters (CHT1) is rate-limiting. Acetylcholine is degraded by acetylcholinesterase
(AChE) into choline and acetate.
SATA Question Q5: Which of the following are ionotropic glutamate receptors? Select all that
apply.
A. NMDA receptors
B. AMPA receptors
C. Kainate receptors
D. mGluR1
, 3
E. GABA-A receptors
F. Glycine receptors
Correct Answers: A, B, C. [CORRECT]
Rationale: Ionotropic glutamate receptors are ligand-gated ion channels comprising three
families: NMDA (N-methyl-D-aspartate), AMPA (α-amino-3-hydroxy-5-methyl-4-
isoxazolepropionic acid), and kainate receptors. These mediate fast excitatory neurotransmission.
mGluR1 is metabotropic (GPCR). GABA-A and glycine receptors are ionotropic but for
inhibitory neurotransmitters, not glutamate.
Q6: Which neurotransmitter is primarily synthesized in the raphe nuclei and projects diffusely
throughout the CNS to regulate mood, sleep, and appetite?
A. Dopamine
B. Norepinephrine
C. Serotonin (5-HT)
D. Histamine
Correct Answer: C. [CORRECT]
Rationale: Serotonergic neurons originate in the raphe nuclei (midline brainstem) and project
widely to cortex, limbic system, and spinal cord. Serotonin (5-hydroxytryptamine) is synthesized
from tryptophan via tryptophan hydroxylase (rate-limiting) and aromatic L-amino acid
decarboxylase. Raphe dysfunction is implicated in depression and anxiety disorders.
Q7: The co-agonist requirement for NMDA receptor activation includes which amino acid in
addition to glutamate?
A. GABA
B. Glycine
C. Dopamine
D. Serotonin
Correct Answer: B. [CORRECT]
Rationale: NMDA receptors require simultaneous binding of glutamate (agonist at GluN2
subunits) and glycine (co-agonist at GluN1 subunits) for channel opening. This dual requirement,
plus voltage-dependent magnesium block, makes NMDA receptors coincidence detectors critical
for synaptic plasticity and learning.
Q8: Which enzyme is responsible for the degradation of acetylcholine in the synaptic cleft?
