1. Matter and Energy – The Foundations of Life 1.3-1.5

2. All Biological Activity Requires Energy Food chains and food webs are based on the cycling of matter from one organism to another organism. All of an organisms activities require energy. Chemical energy is found in the structures that make up the foods that we eat.

3. The Sun and Photosynthesis Supply Food Energy So, where does the chemical energy in your food come from? Photosynthesis is the basis for almost all of the food energy in the world. Animals do not make their own food and must get their energy from plants or other animals.

4. The conversion of chemical energy to the energy used by living organisms is not efficient. Most of the energy escapes as heat. All the energy that enters a food web is eventually lost as heat. Energy must continually enter as photosynthesis into a community or the community will die.

5. Matter Is Used to Build Living Things Matter is never destroyed. It simply changes from one form to another within the food web. Matter is made up of minute particles called atoms. Matter that is made up of a single type of atom forms an element. Most elements occur as molecules, two or more atoms.

6. A compound is matter that is made up of more than one type of atom linked together. Only about 30 of the over 100 elements know make up organisms. Food is matter that can be used to build the structure of the body.