Exam Review: Toxicology and Environmental Pollutants

A collection of vocabulary flashcards covering key terms and concepts related to toxicology, environmental pollutants, and their physiological impacts.

Uptake

The process by which organisms absorb toxicants through various routes such as ingestion, inhalation, or dermal contact.

Toxicokinetics

The study of how toxic substances are absorbed, distributed, metabolized, and eliminated by the body.

Passive diffusion

The process by which contaminants move across biological membranes without energy input, primarily influenced by the compound's hydrophobicity.

Bioaccumulation

The accumulation of substances, such as pesticides or other chemicals, in an organism, often resulting from dietary intake.

Metabolism

The biochemical process by which organisms convert toxic substances into less harmful or more excretable compounds.

Hydrophobicity (Kow)

The octanol-water partition coefficient that indicates how a substance partitions between water and octanol, a surrogate for biological membranes.

First-pass metabolism

The process by which bioactive compounds are metabolized in the liver after being absorbed but before they reach systemic circulation.

Biotransformation

The chemical modification made by an organism on a chemical compound, often resulting in increased water solubility.

Oxidative stress

A condition characterized by excessive reactive oxygen species (ROS) in cells, frequently leading to cell damage or dysfunction.

Chelation therapy

A medical treatment that involves the administration of chelating agents to bind and remove heavy metals from the bloodstream.

Metallothionein

A protein that binds heavy metals, playing a crucial role in detoxification and metal homeostasis.

Reactive metabolites

Metabolites formed during the metabolism of compounds that may have a higher level of toxicity than the parent compound.

Endocrine disruptors

Chemicals that can interfere with endocrine (hormonal) systems, potentially leading to adverse effects on development, reproduction, and other health outcomes.

PCBs (Polychlorinated Biphenyls)

A group of man-made organic chemicals consisting of carbon, hydrogen, and chlorine atoms, known for their environmental persistence and toxicity.

Dioxins

A group of chemically-related compounds known for their harmful health effects, often produced during industrial processes and combustion.

Mitochondrial dysfunction

Disruption in the function of mitochondria, which can lead to reduced energy production and increased oxidative stress within cells.

Antioxidant

A substance that can prevent or slow damage to cells caused by free radicals and oxidative stress.

Thresholds

The dose or concentration of a toxicant below which no adverse effects are expected.

Phase I and Phase II reactions

Two stages of biotransformation, where Phase I involves modifications like oxidation, while Phase II involves conjugation to increase water solubility.

Toxicodynamics

The study of the effects of toxic substances on the body, including how those substances exert their effects at the cellular and organ levels.

Aryl hydrocarbon receptor (AhR)

A protein that mediates the effects of various environmental contaminants, influencing gene expression and related biological responses.