Biology glossary

alteration in a body system in response to environmental change

lacking cells

combination of an acetyl group derived from pyruvic acid and coenzyme A, which is made from pantothenic acid (a B-group vitamin)

neurotransmitter released by neurons in the central nervous system and peripheral nervous system

(AChE) enzyme that breaks down ACh into acetyl and choline

molecule that donates hydrogen ions and increases the concentration of hydrogen ions in a solution

corrosive rain caused by rainwater falling to the ground through sulfur dioxide gas, turning it into weak sulfuric acid; can damage structures and ecosystems

organism with optimal growth pH of three or below

animal without a body cavity

animal without a body cavity

condition caused by overproduction of GH in adults

series of biochemical reactions that the sperm uses to break through the zona pellucida

globular contractile protein that interacts with myosin for muscle contraction

ray-finned fishes

self-propagating momentary change in the electrical potential of a neuron (or muscle) membrane