key words for biology

active site: area on an enzyme that a substrate molecule can fit into 

active transport: the movement of substances against a concentration gradient 

aerobic respiration: respiration that uses oxygen to release energy from glucose

alpha helix: a rod-like structure that contains the backbone of the inner portion of the helix and the side chains on the outer portion

arteriosclerosis: happens to older people, when the walls of the arteries thicken and harden

beta (pleated) sheet: in many proteins where several polypeptide chains and are joined by intermolecular hydrogen bonds

bronchioles: the fine tubes in the lungs that end in alveoli

condensation reaction: when a vapour or a gas is conversed into a liquid

diaphragm: a dome shaped, muscular partition that separates the thorax from the abdomen in mammals. when contracted it increases the volume of the thorax and inflates the lungs

diffusion: the natural movement of particles from an area of high concentration to and area of low concentration

disaccharide: sugars that consist of 2 sugar molecules joined together. sucrose=glucose + fructose

epithelium: thin tissue that covers the outer layer of the body's surface and is also the lining of the stomach

eukaryote: any organism whose cells contain a nucleus and other organelles enclosed within membranes

glycosidic bond: a type of covalent bond that joins a carbohydrate molecule to another group which may or may not be another carbohydrate

hydrogen bond: a weak bond between two molecules due to electrostatic attraction. this happens between a…