| A | B |
|---|
| Carbohydrates | a group of chemicals that include sugars, starches and cellulose |
| lipids | group of chemicals that include fats, oils, waxes, phospholipids, and steroids |
| Proteins | large comple molecules composed of many smaller molecules called amino acids |
| Nucleic acids | large, complex molecules that contain hereditary or genetic info |
| element | a substance that cannot be broken down by chemical processes into simpler substances |
| compound | a substance made of two or more elements chemically combined in definite proportions |
| organic compounds | all compounds taht contain carbon |
| ion | an atom that has lost or gained electrons |
| isotopes | atoms of the same element that have different numbers of neutrons |
| chemical bonds | the attractions that hold two or more atoms together to form a compound |
| ionic bond | the chem bond formed fromt he attractive force between ions |
| covalent bond | when a compound has bonds in which electrons are not gained or lost, but shared by atoms |
| polar molecules | in covalent bonds when atoms do not share electrons equally. as a result some atoms in the molecule have a slightly negative charge and other atoms have a slightly negative charge and some have a slightly positive charge |
| chemical reaction | when one or more substances is changed into a new substance by the breaking or forming of chemical bonds |
| enzyme | a protein catalyst that speeds up the chemical reactions within an organism |
