Pharmacodynamics Vocabulary Flashcards

Vocabulary flashcards defining key principles, drug classifications, and receptor mechanisms from the pharmacodynamics lecture.

Pharmacodynamics

The study of the actions of a drug on the body, focusing on how a drug interacts and what it does once inside the body.

Pharmacology

The study of substances (drugs) that interact with living systems through chemical processes to produce a physiological effect.

Pharmacokinetics

The actions of the body on a drug, encompassing how the body metabolizes and excretes the drug, leading to a limited duration of action.

Physiological receptor

A protein in the body that normally functions as a receptor for a naturally produced endogenous substance, such as acetylcholine or epinephrine.

Generalized receptor

A protein that does not normally function as a receptor in the body, but serves as a binding site for a drug (e.g., a voltage-gated sodium channel).

Rule of 5

A set of parameters defining traditional small-molecule drugs based on multiples of five, such as a molecular weight under $500\,\text{g/mol}$, ideal hydrogen bonding, and moderate lipid solubility.

Biologicals

A category of larger drug molecules—such as peptides, proteins, and antibodies—that do not conform to the rule of five and are typically administered via injection.

Agonist

A drug or substance that binds to a physiological receptor and causes a conformational change that activates the receptor.

Endogenous ligand

A naturally occurring molecule produced within the body (such as a hormone or neurotransmitter) that binds specifically to a receptor.

Antagonist

A drug that binds to a receptor's active site to block the endogenous ligand from binding, without activating the receptor itself.

Allosteric modulator

A drug that binds to a site on a receptor protein separate from the active site, altering the protein's shape to make the receptor's response stronger (positive) or weaker (negative).

Ligand-gated ion channel

A cell-surface protein channel that opens its pore to allow specific ions to pass across the membrane upon the binding of a specific ligand.

G-protein coupled receptor (GPCR)

A transmembrane receptor with seven membrane-spanning segments that, upon agonist binding, dissociates an intracellular G-protein subunit to initiate second messenger cascades.

Enzyme-linked receptor

A single membrane-spanning protein with an extracellular binding domain connected directly to an intracellular enzyme domain.

Receptor tyrosine kinase

A type of enzyme-linked receptor that, when activated by an agonist, attaches phosphate groups specifically to tyrosine residues on cytoplasmic proteins.

Nuclear receptor

An intracellular receptor located in the cytoplasm that, upon binding a lipid-soluble ligand, moves into the nucleus to bind DNA response elements and alter gene expression.