| A | B |
| cells | membrane covered structures that contain all the necessities for life |
| stimulus | anything that causes a reaction or change in an organism or in a part of an organism |
| homeostasis | the maintennance of a constant internal state |
| sexual reproduction | two parents combine genetically to produce offspring |
| asexual reproduction | one parent produces offspring that are identical to the parent |
| DNA | controls the structure and function of cells |
| metabolism | the total of all of the chemical activities that an organism performs |
| producers | make their own food |
| consumers | must get energy from another source |
| proteins | large molecules that are made up of amino acids |
| enzymes | proteins that start or speed up chemical reactions in a cell |
| carbohydrates | molecules that are made up of sugars |
| lipids | compounds that cannot mix with water |
| phospholipids | molecules that make up most of the cell membrane |
| ATP | major energy carrying molecule in the cell |
| nucleic acids | made of nucleotides, give the cell information to make proteins |