| A | B |
| ACID | A compound that produces an excess of hydrogen ions in a water solution. |
| AMINO ACID | The structural unit of proteins. They have at least one amino group (-NH2) and one carboxyl group (-COOH) bonded to a central carbon and- a side chain. |
| ATOMIC MASS (MASS NUMBER) | The total number of protons and neutrons in the nucleus. |
| ATOMIC NUCLEUS | The central core of an atom containing protons and neutrons. |
| ATOMIC NUMBER | The number of protons in the nucleus of an atom. It also indicates the number of electrons in the shells. |
| BASE | A compound that produces an excess of hydroxide (OH-) ions in a water solution. |
| BIOCHEMISTRY | The study of th.e chemistry of living things. |
| CARBOHYDRATE | A compound of carbon hydrogen and oxygen in which the ratio hydrogen to oxygen is 2 |
| CELLULOSE | A carbohydrate present in the cell walls of plants. |
| CHITIN | The polysaccharide that makes up the exoskeleton of arthropods. |
| CONDENSATION REACTION (DEHYDRATION SYNTHESIS) | A type of reaction in which two molecules are bonded together by the removal of a water molecule. |
| COVALENT BOND | A chemicai bond formed by the sharing of electrons. |
| DISACCHARIDE | A double sugar formed by two monosaccharides joined by a dehydration synthesis. |
| DNA (DEOXYRIBONUCLEIC ACID) | The nucleic acid that contains hereditary information; the genetic material. |
| ELECTRON | A negatively-charged particle found in the space outside the nucleus of an atom. |