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Cellular respiration is the process by which organisms use oxygen to break down food molecules to get chemic free energy for cell functions. Cellular respiration takes place in the cells of animals, plants, and fungi, and too in algae and other protists. It is often called aerobic respiration considering the process requires oxygen (the root aer comes from the Greek discussion for "air"). In the absence of oxygen, cells tin can get energy by breaking downwards food through the process of fermentation, or anaerobic respiration. Of the two processes, cellular respiration is more efficient, yielding considerably more energy than that released through fermentation.

Cellular respiration is a chemical reaction in which glucose is cleaved down in the presence of oxygen, releasing chemical free energy and producing carbon dioxide and water as waste material products:

glucose + oxygen → chemic energy + carbon dioxide + water

The energy released is captured in molecules of adenosine triphosphate, or ATP, which and so supply it to fuel other cellular processes (run across biochemistry).

Encyclopædia Britannica, Inc.

All cells demand energy to function. But every bit a car must burn fuel to get the energy it needs to run, the cell must burn fuel—for example, food—to get free energy to deport out the tasks of life. Glucose, a simple saccharide, provides the fuel the cell needs. Although energy is as well stored in larger molecules, such as complex carbohydrates and fats, they must be broken down into molecules of glucose earlier the cell can utilize their energy.

Almost of cellular respiration takes place in sausage-shaped organelles called mitochondria. Although mitochondria play a primal role in other cellular processes, their principal function is to produce big amounts of energy through cellular respiration. The number of mitochondria per cell varies; liver and muscle cells, which require large amounts of energy to function, may accept thousands. (Come across likewise cell.)

Cellular respiration begins in the jail cell's cytoplasm. There, glucose is broken down through a serial of chemical reactions to produce small molecules of a substance called pyruvate. This part of the procedure is called glycolysis; information technology does not require oxygen and releases a small corporeality of energy, which is captured past a few ATPs. The pyruvate molecules then enter the mitochondria, where they undergo a series of chemic reactions with oxygen. So much free energy is released in these reactions that it takes many molecules of ATP to capture it all. The reactions also release hydrogen, which combines with oxygen to produce water; and carbon, which combines with oxygen to produce carbon dioxide. The h2o and carbon dioxide are released every bit waste products; the ATPs leave the mitochondria and deliver their captured energy to places in the cell where it is needed to power cellular activities.