CELL ENERGY

Cells need energy to stay alive!



Energy for cells comes in the form of food--carbohydrates (sugars), fats / lipids, and proteins. Cells use this energy to drive their daily activities. In many multicellular organisms, these large food particles are broken down into small molecules in a process called digestion. These smaller molecules are able to enter the cell through the cell membrane. Once inside the cell , these small molecules (sugars, amino acids) are taken apart, rearranging their bonds to form energy-storing molecules like ATP. This ATP is used to power the activities of the cell.





Green plants and a few other kinds of organisms are able to make their own food using sunlight, water, carbon dioxide and chlorophyll in a process called photosynthesis. These cells are adapted to complete the photosynthetic process because they contain specialized organelles called chloroplasts. Inside each chloroplast is the chemical called chorophyll (green) that literally uses the sun's light to power photosynthesis. The sole purpose of the process of photosynthesis is to make food for the organism. All forms of life--from bacteria to plants to the cells in your body--depend on plant cells for the food they create in the process of photosynthesis.