Energy for Life Metabolism the total of all chemical reactions in an organism. All activities an organism performs involve chemical reactions in some way. Enzymes (special proteins) are needed for chemical reactions to occur.

Photosynthesis Producers capture energy from the sunlight through pigments such as green pigment in chlorophyll. Consumers need to obtain their energy from producers or other consumers. Plants produce carbohydrates. Photosynthesis uses carbon dioxide and water in the presence of sunlight to produce sugar and oxygen.

Storing Carbohydrates Plants produce more sugar then they need. The extra sugar is converted and stored as starch or other carbohydrates.