Glycolysis
Glycolysis literally means "-splitting." In glycolysis, the -carbon sugar glucose is split into molecules of pyruvate, also called acid. This process produces a net gain of ATP molecules. The resulting molecules of pyruvate each have carbon atoms. Glycolysis takes place in the cell's . The remainder of cellular respiration takes place in organelles called .
The Krebs Cycle
The Krebs Cycle takes place in the fluid-filled area inside the inner membrane of the mitochondria known as the . Some and other energy carrying molecules are produced here. The gas is a byproduct of this process.
The Electron Transport Chain
Most of the is produced in this last step of cellular respiration. Electron transport takes place in the infoldings of the inner-membrane of the mitochondria. These infoldings are called . At the end of electron transport, combines with hydrogen ions and (e^-) to form . Overall Process
Fermentation
In the absence of , the cell resorts to anaerobic metabolism. In animal cells, pyruvate is converted to acid. In yeast and bacteria, the pyruvate is often converted to . In both cases, no new ATP is produced, so the net production of the -carrying molecule is only the molecules of ATP produced in glycolysis.