Exam 3

Pharmacology

Interaction of chemicals with biological systems, focusing on mechanism of action, therapeutic effects, and potential side effects

Pharmacodynamics

What the drug does to the body, how drug interacts with cellular targets and how these interactions produce biological responses

Pharmacokinetics

What the body does to the drug, absorption, distribution, metabolism, and excretion

Receptor

A protein molecule found on surface or within cells, binds to a specific signaling molecule to initiate a cellular response

Ligand

Any chemical that will bind to a receptor

Agonist

A ligand that activates a receptor and generate a biological response

Antagonist

A chemical that prevents or reduces a biological response, may act at a receptor or by other mechanisms

Drug

Chemical that alters physiologic function of cells and tissues through a chemical reaction, prevents/treats/ gives symptomatic relief of disease, scientific tool to study cell/tissue function

Neurotransmitters

Chemical messengers released by neurons that transmit signals across a synapse to target cells, fast acting

What are the examples of neurotransmitters

Norepinephrine, acetylcholine, GABA, and 5-HT

Hormones

Chemical messengers secreted by glands into the bloodstream, travel to target tissues or organs to regulate long-term processes, slower acting

What are examples of hormones?

Aldosterone, estrogen, thyroid hormone

What are the types of agonists

Full, partial, inverse, allosteric, biased

What are the types of antagonists?

Physiologic, chemical, competitive, noncompetitive, allosteric

What is the MW of a ligand?

100-1000g/mole

Lock and key hypothesis

Earliest model, ligands have a complementary shape to the receptor for binding to occur

How do functional groups affect ligand- receptor binding?

They allow a chemical bond to form between the drug ad the receptors binding pocket

Function of a receptor

Site of neurohormone and drug action, regulate physiological systems, regulate biochemical processes

Where can receptors be located?

Cell membrane, cytoplasm, and nucleus

Transduction

Transmitting information into and throughout the cell

What are the types of membrane receptors?

G-protein coupled receptor, ligand gated ion channels, enzymatic, and cytokine

What are the types of intracellular receptors?

Nuclear and cytoplasmic

Ligand-binding domain

Binds specifically to the ligand

Transmembrane domain

Hydrophobic, spans the lipid bilayer, anchors the receptor to the membrane

Effector/ signaling domain

Interacts with signaling proteins

Affinity

Strength of the interaction between a receptor and drug, Kd, higher Kd=lower affinity

Selectivity

Describes a drugs preference/ affinity for one receptor/target over another

Specificity

A precise molecular complementarity between the signal and receptor molecules, mediated by noncovalent forces

How can a high dose of a drug affect selectivity or specificity?

It can reduce both

Signal transduction

Cells communicating using extracellular signaling molecules produced and released by signaling released, the molecules recognized and bind to receptors on the surface of target cells to cause a cellular response through a signal transduction pathway

What are the types of signaling?

Autocrine, paracrine, endocrine

Autocrine

Cell secretes chemical messenger/ hormones that will then activate receptors on the same cell

Paracrine

Cell secretes a chemical messenger/ hormone that will then activate cell-surface receptors on a cell nearby

Endocrine

Cell secretes chemical messenger/ hormone that needs to be transported by the bloodstream to reach a distant target cell

Neuroendocrine cells

Receive neuronal input and release hormones to the bloodstream

Sensitivity

High