| Term | Definition |
|---|---|
| photosynthesis | a series of chemical reactions that convert light energy , water and carbon dioxide into the food-energy molecule glucose and give off oxygen |
| cellular respiration | a series of chemical reactions that convert the energy in food molecules into a usable form of energy called ATP. |
| Adenosine Triphosphate (ATP) | molecule found in all living organisms that is the main immediate source of usable energy for the activities of the cells. |
| evaporation | process during which liquid water changes into a has called water vapor. |
| condensation | process during which water vapor changes into liquid water. |
| precipitation | water that falls from clouds to Earth's surface. |
| nitrogen fixation | process that changes atmospheric nitrogen into nitrogen compounds that are usable by living things . |
| chemosynthesis | process during which producers use chemical energy in matter rather than light energy and make food |
| food chain | model that shows how energy flows in an ecosystem through feeding relationships |
| food web | shows how food chains in a community are interconnected. |
| energy pyramid | shows the amount of energy available in each step of a food chain. |
