Cellular respiration is a process that occurs in animal cells. This process is used to manufacture energy for the cell, usually stored within the cell in the form of ATP. The reactants that produce this energy are glucose (C6H12O6) that is extracted from the food the animal eats by the digestive system, and oxygen, which is breathed in by the animal's respiratory system. The overall reaction produces the aforementioned energy, stored in the form of ATP (adenosine triphosphate), plus water and carbon dioxide as waste products. The general equation looks like this:
C6H12O6 + O2 ---> energy (ATP) + CO2 + H2O
There are some "in between steps. The electron transport chain is the mechanism that causes this reaction to happen. This is when oxygen in the equation is converted to water and NADH, which is converted to an ionic NAD+, causing the electrons to be transferred across the walls of the mitochondrion. That part of the reaction looks like this:
C6H12O6 + O2 ---> NADH + O2-2 ---> NAD+ H2O + CO2 ---> energy (ATP) + H2O + CO2
Cellular respiration occurs in both plants and animals it is the release of energy from glucose. Aerobic respiration requires oxygen and glucose and produces energy, water and carbon dioxide. Anaerobic respiration requires glucose and produces a little energy, carbon dioxide and lactic acid.