How does the process of cellular respiration work?
A cell extracts energy from glucose and puts it in a more usable form, as ATP.
Cells take in glucose from nutrients. Glucose is formed in plants from photosynthesis and travels through the food chain and environment.
Glucose goes through four separate processes inside respiration: glycolysis, link reaction, Krebs cycle and the Electron Transport Chain. In these processes the energy from glucose travels through various molecules until it gets to ATP.
ATP stands for adenosine triphosphate, because it is made from an adenose sugar head and three phosphates as a tail. When energy is needed, ATP cuts off a phosphate and energy from the bonds travels into the immediate environment.
Respiration takes place mostly in the mitochondria, though some reactions take place in the cytoplasm of the cell.
The overall equation for respiration is
Oxygen is inhaled. In humans it travels through the bloodstream until it gets to cells where it is needed. Carbon dioxide is then produced and exhaled or diffuses out of the cell. Water stays mostly in the body because it can be used again.
The energy from glucose can be put, ideally, into 34 ATP molecules, though this doesn't account for mistakes in the process - no cell is perfect.