Core MCAT Vocabulary Words (50+)
A strong command of scientific and research terminology boosts speed and accuracy on MCAT passages and questions.
This curated list of 50 high‑yield terms spans physiology, biochemistry, genetics, immunology, neuroscience, and experimental design.
Each entry includes a concise definition, an easy “essence” cue, a clear example, and a quick MCQ for retrieval practice.
homeostasis
Example: Thermoregulation helps maintain homeostasis during exercise.
Homeostasis refers to:
allosteric
Example: An allosteric inhibitor reduces enzyme activity without blocking the active site.
An allosteric inhibitor binds to the:
antagonist
Example: Beta blockers are antagonists at β‑adrenergic receptors.
A receptor antagonist typically:
agonist
Example: Morphine is a μ‑opioid receptor agonist.
An agonist:
affinity
Example: A lower KD indicates higher affinity.
Higher affinity corresponds to:
efficacy
Example: A partial agonist has lower efficacy than a full agonist.
Drug efficacy is best described as:
potency
Example: A left‑shifted dose‑response curve indicates greater potency.
Greater potency means:
isotonic
Example: Red blood cells in isotonic saline maintain normal volume.
An isotonic solution has solute concentration:
hypertonic
Example: Cells shrink in a hypertonic environment due to water efflux.
In a hypertonic solution, cells tend to:
hypotonic
Example: Cells swell in a hypotonic solution as water enters.
In a hypotonic solution, cells usually:
osmolarity
Example: Plasma osmolarity is tightly regulated by ADH.
Osmolarity measures:
synapse
Example: Neurotransmitters cross the synaptic cleft to bind receptors.
Signals between neurons are transmitted at the:
depolarization
Example: Opening Na+ channels causes rapid depolarization.
Depolarization makes the neuron interior:
paracrine
Example: Growth factors often act via paracrine signaling.
Paracrine signals act on:
autocrine
Example: Some cancer cells use autocrine loops to promote growth.
Autocrine signaling targets:
allele
Example: The child inherited one dominant and one recessive allele.
An allele is best described as a:
penetrance
Example: A dominant mutation with incomplete penetrance is not always expressed.
High penetrance means a genotype:
pleiotropy
Example: The gene exhibits pleiotropy, affecting both vision and metabolism.
Pleiotropy occurs when one gene:
epistasis
Example: In coat color, epistasis can mask pigment production genes.
Epistasis refers to:
oncogene
Example: Mutations in RAS often lead to oncogene activation.
Oncogenes usually promote:
tumor suppressor
Example: Loss of p53 tumor suppressor function leads to malignancy.
Tumor suppressors usually:
apoptosis
Example: Damaged DNA often triggers apoptosis via caspases.
Apoptosis is also known as:
necrosis
Example: Ischemia leads to necrosis of tissue.
Necrosis differs from apoptosis because it is:
angiogenesis
Example: Tumors stimulate angiogenesis for nutrients and oxygen.
Angiogenesis means:
cytokine
Example: Interleukins are cytokines regulating immune responses.
Cytokines function mainly in:
antibody
Example: IgG antibodies provide long-term immunity.
Antibodies are made by:
antigen
Example: Pathogen proteins act as antigens in the body.
An antigen is:
innate immunity
Example: Skin and macrophages are part of innate immunity.
Innate immunity is:
adaptive immunity
Example: Vaccination works by stimulating adaptive immunity.
Adaptive immunity is unique because it:
clonal selection
Example: Clonal selection ensures specificity in immune responses.
Clonal selection ensures that immune cells:
hematopoiesis
Example: Hematopoiesis occurs in the bone marrow.
Hematopoiesis occurs mainly in the:
erythropoietin
Example: Kidneys release erythropoietin in response to hypoxia.
Erythropoietin stimulates production of:
hemostasis
Example: Platelets and clotting factors mediate hemostasis.
Hemostasis refers to:
platelet
Example: Low platelet count leads to excessive bleeding.
Platelets are primarily involved in:
coagulation
Example: Fibrin formation is central to coagulation.
Coagulation results in:
embolism
Example: A pulmonary embolism can be life-threatening.
An embolism is caused by:
ischemia
Example: Coronary ischemia causes angina.
Ischemia results from:
infarction
Example: Myocardial infarction is commonly called a heart attack.
Infarction refers to:
endocrine
Example: The thyroid is part of the endocrine system.
Which system releases hormones into the blood?
exocrine
Example: Sweat glands are exocrine glands.
Exocrine glands release substances via:
neurotransmitter
Example: Serotonin is a neurotransmitter affecting mood.
Neurotransmitters are released at:
action potential
Example: Action potentials travel along axons to communicate signals.
Action potentials are:
blood–brain barrier
Example: The blood–brain barrier prevents toxins from entering the brain.
The blood–brain barrier mainly:
neuroplasticity
Example: Stroke patients recover function through neuroplasticity.
Neuroplasticity refers to:
placebo effect
Example: Patients often report relief from sugar pills due to placebo effect.
The placebo effect occurs when:
double-blind study
Example: Double-blind studies eliminate placebo bias.
In a double-blind study, who knows the treatment group?
confounding variable
Example: Age may act as a confounding variable in medical studies.
A confounding variable:
FAQ
Quick answers to common questions.