| A | B |
|---|
| compound | Substance made of atoms of different elements that are bonded together in a particular ratio |
| molecule | Two or more atoms held together by covalent bonds |
| catalyst | A substance that lowers the activation energy and increases the reaction rate in a chemical reaction. |
| enzyme | Substance that speeds-up chemical reactions in organisms. |
| substrate | The part of a chemical reaction that enzymes act on. |
| element | A substance made of only one type of atom and can not be broken down by chemical means. |
| monomer | A subunit of a complete molecule. Small molecules that form a larger molecule. |
| polymer | A large molecule that is made of many smaller molecules bonded together. |
| reactant | A substance that is changed by a chemical reaction. |
| product | A substance that is formed by a chemical reaction. |
