Biochemistry Vocabulary

Honors Bio with Dr. Kohler - Test Date 9/21/26

Atom

basic unit of matter

Element

substance consisting entirely of one type of atom

Compound

substance formed by the chemical combination of two or more elements in definite proportions

Electron

negatively charged particle; located outside the atomic nucleus

Molecule

smallest unit of most compounds

Nucleus

the center of the atom which contains the protons and neutrons; in cells, structure that contains the cell’s genetic material (DNA) and controls the cell’s activities

Ion

atom that has a positive or negative charge

Isotope

atom of an element that has a number of neutrons different from that of other atoms of the same element

Ionic Bond

bond formed when one or more electrons are transferred from one atom to another

Covalent Bond

bond formed by the sharing of electrons between atoms

Van der Waals forces

a slight attraction that develops between the oppositely charged regions of nearby molecules

Cohesion

attraction between molecules of the same substance

Adhesion

attraction between molecules of different substances; in plants, attraction between unlike molecules

Mixture

material composed of two or more elements or compounds that are physically mixed together but not chemically combined

Solution

mixture of two or more substances in which the molecules of the substances are evenly distributed

Solute

substance that is dissolved in a solvent to make a solution

Solvent

substance in which a solute is dissolved to form a solution

Suspension

mixture of water and non-dissolved materials

Acid

compound that forms hydrogen ions (H+) in solution

Base

compound that produces hydroxide ions (OH+) in solution

pH Scale

measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0-14

Buffer

weak acid or base that can react with strong acids or bases to help prevent sharp, sudden changes in pH

Monomer

small unit that can join together with other small units to form polymers

Polymer

large compound formed from combinations of many monomers

Carbohydrate

compound made up of carbon, hydrogen, and oxygen atoms; major source of energy for the human body

Monosaccharide

single sugar molecule

Polysaccharide

large macromolecule formed from monosaccharides

Lipid

macromolecule made mainly from carbon and hydrogen atoms; includes fats, oils, and waxes

Protein

macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair and to make up enzymes

Nucleic Acid

macromolecule containing hydrogen, oxygen, nitrogen, carbon, and phosphorus

Nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

RNA

single-stranded nucleic acid that contains the sugar ribose

DNA

nucleic acid that contains the sugar deoxyribose

Amino Acid

compound with an amino group (-NH2) on one end and a carboxyl group (-COOH) on the other end

Chemical Reaction

process that changes one set of chemicals into another set of chemicals

Reactant

element or compound that enters into a chemical reaction

Product

element or compound produced by a chemical reaction

Activation Energy

energy needed to get a reaction started

Catalyst

substance that speeds up the rate of a chemical reaction

Enzyme

protein that acts as a biological catalyst

Substrate

reactant of an enzyme-catalyzed reaction