How is food used by the body?

Answer 1

Food is broken down to the molecular level, so its nutrients can be distributed through the blood stream, and so glucose in the food can be converted to glycogen for storage purposes. To get energy from the food, glucose undergoes a process called cellular respiration, where glucose is broken down in glycolysis to release ATP, NADH, and FADH2. ATP is energy that is ready to be used. NADH and FADH2 go through the Krebs cycle, where some of the energy the carry is converted into ATP. The remaining NADH and FADH2 are transported to the Electron Transport Chain (ETC). In the ETC, oxygen that is inhaled accepts the electrons that they carry and they are converted into ATP. There is still a large amount of energy that is unused, and this energy is released as heat and light to keep your body temperature stable.