Biology: Chemistry of Life

acid

A substance that increases the hydrogen ion concentration of a solution.

activation energy

Energy needed to get a reaction started

adhesion

An attraction between molecules of different substances

amino acid

Building blocks of protein

atom

Basic unit of matter

base

A substance that decreases the hydrogen ion concentration in a solution.

buffer

compound that prevents sharp, sudden changes in pH

carbohydrate

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

catalyst

substance that speeds up the rate of a chemical reaction

choesion

Attraction between molecules of the same substance

compound

A substance made up of atoms of two or more different elements joined by chemical bonds

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

electron

A subatomic particle that has a negative charge

element

A pure substance made of only one kind of atom

enzyme

A type of protein that speeds up a chemical reaction in a living thing

homeostasis

A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level

hyrdrogen bond

weak attraction between a hydrogen atom and another atom

ion

A charged atom

ionic bond

Formed when one or more electrons are transferred from one atom to another

isotope

Atoms of the same element that have different numbers of neutrons

lipid

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

mixture

A combination of two or more substances that are not chemically combined

molecule

A group of atoms bonded together

Monomer

A simple compound whose molecules can join together to form polymers

monosaccharide

A single sugar molecule such as glucose or fructose, the simplest type of sugar.

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

nucleus

Control center of the cell

pH scale

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

polarity

A lack of electrical symmetry in a molecule. Charge differences on opposite ends of a structure.

polymer

A long molecule consisting of many similar or identical monomers linked together.

product

A substance produced in a chemical reaction

protein

A three dimensional polymer made of monomers of amino acids.

reactant

A chemical substance that is present at the start of a chemical reaction

solute

A substance that is dissolved in a solution.

solution

A homogeneous mixture of two or more substances

solvent

A liquid substance capable of dissolving other substances

substrate

reactant of an enzyme-catalyzed reaction

suspension

A mixture in which particles can be seen and easily separated by settling or filtration

van der Waals forces

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

water

universal solvent