What Is Cellular Respiration

Your body needs energy for functioning and this energy is available from the food you eat. The process by which the cells of your body derive energy from the food stored in them is called ‘cellular respiration'. Now to answer ‘what is cellular respiration?' the definition given below must be sufficient:

“The set of metabolism and all the processes that take place in the cells of body for breaking down food nutrients into ATP (adenosine triphosphate) releasing energy is called cellular respiration”.

For performing reformations inside the cell, the cell gains energy mainly from respiration. To perform the process of respiration, plant and animal cells use fatty acid, sugar, amino acid and oxygen molecule from food. The energy extracted is then stored in ATP molecules and from where it is involved in various processes of body that require energy.

Now that you have seen ‘what is cellular respiration', here are some important points related to the process. You must know the outline of the three stages involved in the process, if you don't have this much of idea, your knowledge about what is cellular respiration, will not be considered sufficient. The three stages in the process of cellular respiration are:

1. Glycolysis – the very first stage of cellular respiration, glycolysis involves break down of glucose or sugar molecule into two three-carbon sugar molecules. During the process of glycolysis, two ATP molecules, two pyruvic acid molecules and two electrons with high energy are formed. These high energy molecules carry the molecules of NADH. The process of glycolysis can take olace in presence as well as absence of oxygen. Process of fermentation occurs in absence of oxygen. ATP is produced in fermentation.
2. Citric acid cycle – this is also known as Kreb's cycle. This begins when the three-carbon sugar molecules that are produced in above process, are converted to acetyl CoA. The Kreb's cycle or citric acid cycle takes place only in the presence of oxygen but oxygen is not directly used in this process.
3. Electron transport – this process involves direct use of oxygen. It is basically an electron career series in the mitochondrial membrane of eukaryotic cells. The electrons with high energy are carried to oxygen through a chain of reaction. The ultimate product formed in this process is ATP after the formation of a gradient.