Neurochemistry Test – Questions and Answers | MCQ Quiz | OmpathStudy Kenya

Question 1

What neurotransmitter is associated with runner's high?

Accepted Answer

Endorphins — Endorphins are the body's natural opioids that create feelings of euphoria and pain relief. During intense exercise like running, the body releases endorphins, which bind to opioid receptors and produce the characteristic "runner's high" - a feeling of well-being and reduced pain perception. ---

Question 2

Where do neurons store the genetic information they use to code and build all the proteins required for their functions?

Accepted Answer

In the nucleus — The nucleus contains the cell's DNA, which stores all genetic information. This DNA is transcribed into mRNA, which then travels to ribosomes for protein synthesis. The nucleus is the central control center for all cellular functions. ---

Question 3

The effect of tetrodotoxin (puffer fish poison) on axons demonstrates

Accepted Answer

The role of sodium channels in depolarization — Tetrodotoxin specifically blocks voltage-gated sodium channels, preventing action potentials from occurring. This demonstrates that sodium influx through these channels is essential for depolarization and action potential generation. ---

Question 4

What neurotransmitter is associated with mood disorders?

Accepted Answer

Serotonin — Serotonin is strongly associated with mood regulation. Low serotonin levels are linked to depression, anxiety, and other mood disorders. SSRIs (Selective Serotonin Reuptake Inhibitors) are commonly prescribed antidepressants that increase serotonin availability. ---

Question 5

What neurotransmitter is associated with seizures?

Accepted Answer

Glutamate — Glutamate is the primary excitatory neurotransmitter in the brain. Excessive glutamate activity or insufficient GABA inhibition can lead to seizures, as the brain becomes hyperexcitable with uncontrolled neuronal firing. ---

Question 6

What is one of the functions of Dopamine?

Accepted Answer

Pleasure — Dopamine is central to the brain's reward system and pleasure pathways. It's released in response to rewarding experiences and motivates behavior toward pleasurable activities. This is why dopamine is often called the "feel-good" neurotransmitter. ---

Question 7

What is one of the functions of Endorphins?

Accepted Answer

Pleasure — Endorphins are the body's natural opioids that produce feelings of pleasure and well-being. They're released during exercise, stress, pain, and other activities, binding to opioid receptors to create euphoric feelings and reduce pain perception. ---

Question 8

What neurotransmitter is associated with Alzheimer's disease?

Accepted Answer

Acetylcholine — Alzheimer's disease involves significant loss of acetylcholine-producing neurons, particularly affecting memory and cognitive function. Cholinesterase inhibitors, which increase acetylcholine availability, are used as treatments for Alzheimer's. ---

Question 9

Which of the following best discriminates between small-molecule neurotransmitters and peptide neurotransmitters?

Accepted Answer

Peptide neurotransmitter precursors and their enzymes are axonally transported in vesicles — Peptide neurotransmitters are synthesized in the cell body and transported down the axon in vesicles, while small-molecule neurotransmitters are typically synthesized locally at nerve terminals. This is a key distinguishing feature between these two types of neurotransmitters. ---

Question 10

Which neurotransmitter is released by the postganglionic neurons of the sympathetic nervous system?

Accepted Answer

Norepinephrine — Most postganglionic sympathetic neurons release norepinephrine (noradrenaline) as their neurotransmitter. This activates adrenergic receptors on target organs, producing the "fight or flight" response characteristic of sympathetic activation. ---

Question 11

A neuron cannot produce an action potential

Accepted Answer

Both b and d — During the absolute refractory period, sodium channels are inactivated and cannot be reopened regardless of stimulus strength. This ensures unidirectional propagation of action potentials and limits firing frequency. ---

Question 12

Synaptic autoreceptors normally

Accepted Answer

Reduce neurotransmitter release at a synapse — Autoreceptors provide negative feedback control. When activated by the neurotransmitter they respond to, they reduce further neurotransmitter release, serving as a self-regulating mechanism to prevent excessive synaptic activity. ---

Question 13

The process whereby the content of synaptic vesicles is released into the synaptic cleft/gap is called

Accepted Answer

Exocytosis — Exocytosis is the process by which synaptic vesicles fuse with the presynaptic membrane and release their neurotransmitter contents into the synaptic cleft. This is triggered by calcium influx following action potential arrival. ---

Question 14

Small transmitter molecules are

Accepted Answer

Packaged in small synaptic vesicles — Small molecule neurotransmitters (like acetylcholine, dopamine, serotonin) are stored in small, clear synaptic vesicles, typically synthesized locally at nerve terminals, unlike peptide neurotransmitters which are made in the cell body. ---

Question 15

Which one of the following is not a criterion for small neurotransmitter (NT) status?

Accepted Answer

Packaged in large synaptic vesicles — Small molecule neurotransmitters are packaged in small synaptic vesicles, not large ones. Large dense-core vesicles are typically used for peptide neurotransmitters and neuromodulators. ---

Neurochemistry Test – Questions and Answers | MCQ Quiz | OmpathStudy Kenya

Questions, Answers & Explanations