BIOSYNTHESIS OF
NEUROTRANSMITTERS EXAM WITH
100% CORRECT ANSWERS { GRADED
A+}
Neurotransmitter -✔✔ local action; released from nerve terminal in response to an
action potential
Hormones -✔✔ another example of first messengers but they have global action;
released from endocrine cells and travel through circulation
Ligand Activated Ion Gates -✔✔ sodium or calcium entry depolarizes the cell,
promoting an action potential; chloride influx hyperpolarizes the cell, inhibiting the
action potential
Metabotropic Receptors -✔✔ alter the enzyme activities inside the cell such as
kinase
, Biogenic Amines -✔✔ five serve as neurotransmitters including catecholamines
(dopamine, epinephrine, norepinephrine), histamine, and serotonin; derived from
tyrosine, histidine, or tryptophan; are important in a wide range of behaviors; many
drugs target synthesis, receptors binding/action, or catabolism
Catecholamine Synthesis -✔✔ tyrosine --> DOPA --> dopamine -->
norepinephrine --> epinephrine; the key enzyme is tyrosine hydroxylase with
cofactors pyridoxal phosphate and vitamin C
Catecholamine Release -✔✔ neurotransmitters are contained and transported in
synaptic vesicles; when depolarization of the cell induces calcium influx, calcium-
dependent exocytosis occurs to release the catecholamines; action is mediated by
neurotransmitter binding to specific receptors on the postsynaptic cell
Catecholamine Removal -✔✔ the remaining neurotransmitter in the synaptic cleft
is cleared by sodium-dependent transporters on the presynaptic neuron; most
catecholamines are reused, and some are destroyed (MAO, COMT)
Catecholamine Catabolism -✔✔ breaking down of catecholamines occurs mainly
in the liver and the kidney using the two working enzymes MAO and COMT,
though their order is not essential; ultimately results in the production of
NEUROTRANSMITTERS EXAM WITH
100% CORRECT ANSWERS { GRADED
A+}
Neurotransmitter -✔✔ local action; released from nerve terminal in response to an
action potential
Hormones -✔✔ another example of first messengers but they have global action;
released from endocrine cells and travel through circulation
Ligand Activated Ion Gates -✔✔ sodium or calcium entry depolarizes the cell,
promoting an action potential; chloride influx hyperpolarizes the cell, inhibiting the
action potential
Metabotropic Receptors -✔✔ alter the enzyme activities inside the cell such as
kinase
, Biogenic Amines -✔✔ five serve as neurotransmitters including catecholamines
(dopamine, epinephrine, norepinephrine), histamine, and serotonin; derived from
tyrosine, histidine, or tryptophan; are important in a wide range of behaviors; many
drugs target synthesis, receptors binding/action, or catabolism
Catecholamine Synthesis -✔✔ tyrosine --> DOPA --> dopamine -->
norepinephrine --> epinephrine; the key enzyme is tyrosine hydroxylase with
cofactors pyridoxal phosphate and vitamin C
Catecholamine Release -✔✔ neurotransmitters are contained and transported in
synaptic vesicles; when depolarization of the cell induces calcium influx, calcium-
dependent exocytosis occurs to release the catecholamines; action is mediated by
neurotransmitter binding to specific receptors on the postsynaptic cell
Catecholamine Removal -✔✔ the remaining neurotransmitter in the synaptic cleft
is cleared by sodium-dependent transporters on the presynaptic neuron; most
catecholamines are reused, and some are destroyed (MAO, COMT)
Catecholamine Catabolism -✔✔ breaking down of catecholamines occurs mainly
in the liver and the kidney using the two working enzymes MAO and COMT,
though their order is not essential; ultimately results in the production of
