Cellular respiration is the process of breaking down glucose molecules into energy in the form of ATP. The process requires oxygen and gives off carbon dioxide as a waste product. ATP powers all cellular activities.
In respiration glucose molecules react with oxygen atoms to form carbon dioxide and water. In this chemical reaction energy is released in stored in the form of ATP. In the reaction glucose is oxidized and energy is released.
There are three stages in cellular respiration. Glycolysis is the first step in which glucose is broken down into pyruvate. The process results in energy carrying molecules called NADH. A small amount of ATP is also made and CO2 is given off as a byproduct. Glycolysis occurs in the cytoplasm of the cell. The pyruvate is then brought into the mitochondria and used in the citric acid cycle (Kreb’s Cycle). This cycle brakes down pyruvate further and produces small amounts of ATP and CO2. The most important function of the citric acid cycle and glycolysis is to provide the electron transport chain with electron carriers. The electron transport chain also takes place within the mitochondria. This final stage of respiration yields the highest amounts of ATP.
Experiences, Patterns, and Explanations
1. Explain the process of food storage and food use in organisms. (using)
2. Explain how multicellular organisms grow. (using)
3. Explain the process of respiration as it relates to breathing in organisms. (using)
4. Explain how the process of respiration creates energy for the cell. (using)
5. Explain differences between aerobic and anaerobic respiration. (using)