| A | B |
|---|
| Atom | The smallest part of an element. |
| Protons | Part of an atom; has a positive charge |
| Neutrons | Part of an atom; has no charge |
| Electrons | Part of an atom; has a negative charge |
| Molecule | Two or more atoms joined together |
| Compound | A molecule with two or more different atoms of elements |
| Proteins | A molecule made up of amino acids; humans have over 20 different ones |
| Carbohydrates | Sugars and starches; made up of carbon, hydrogen, and oxygen |
| Lipids | Fatty compounds; made up of carbon, hydrogen, and oxygen |
| Nucleic Acids | Information carrying molecules such as DNA |
| Phospholipids | A cell membrane is built around these |
| Water | Important substance to a cell; can cause a cell to burst |
