Energy is needed by our body whenever its cells indulge any type of “work”. This energy or fuel for the body is produced by the break down of food we eat, essentially the carbohydrates, proteins and fats present in it. A number of chemical processes are carried out within the body to break down food and produce energy. One such process is the removal of molecules and production of heat. Carbohydrates, proteins and fats, thus converted into energy, are taken to different paths within the body. If you are wondering how the fat is burnt by the body, go through the following lines.
Before knowing how fat is burnt by the body, you should know the following terms related to the chemical process:
- ATP: The body makes use of Adenosine Tri-Phosphate (ATP) energy as fuel for the cells. ATP can be produced by using oxygen (aerobic) as well as without the presence of oxygen (anaerobic).
- Glycolysis: The anaerobic process of the conversion of glucose to pyruvic acid is known as Glycolysis.
- Pyruvic Acid: Pyruvic acid is converted into Acetyl-CoA in the presence of oxygen. If the oxygen is not available, it is converted into lactic acid.
- Acetyl-CoA: This is an important molecule in the process of metabolism. The main function of this molecule is to convey the carbon atoms within the acetyl group to the citric acid cycle, to be oxidized for the production of energy.
- Krebs Cycle: This eight-step cycle removes hydrogen and carbon-dioxide, amongst other things. A small amount of ATP is also produced by Krebs Cycle.
- Electron Transport Chain: This is the final step in the breakdown of food. Most of the ATP is formed in the electron transport chain.
How Is Fat Burned By Human Body
Although there are a number of fats present in the body, it is the triglycerides, or “neutral fats”, that are generally converted to energy. The sources of the triglycerides are stored fat and the food we eat. As much as 441 ATP molecules are produced by the single triglyceride.
The Break-Down Of Triglycerides
The process of breaking down of triglycerides is known as Lipolysis. In this process, a single triglyceride is broken down to one molecule of glycerol and three molecules of fatty acids.
Conversion To Acetyl-CoA
The glycerol and fatty acids follow different path, even though their product is the same. Before entering the Krebs Cycle, both of them should be converted to the molecule - Acetyl-CoA.
Glycerol To Acetyl-CoA
Glycerol is a basic sugar that follows the pathway of glycolytic pathway (Glycolysis). During the process of Glycolysis, glycerol is converted into pyruvic acid. The pyruvic acid is converted to acetyl CoA before it enters the Krebs Cycle. This is done is three steps. In the first step, one carbon is removed from the pyruvic acid and released as carbon dioxide, which is released from the cell and exits via the lungs. Removal of hydrogen atoms is done in the second step. In the last step, acetic acid is combined with coenzyme A to form Acetyl-CoA.
Fatty Acids To Acetyl Coa
Beta-oxidation is a chemical process, in which, fatty acids are converted into Acetyl-CoA. The fatty acid chains are broken in this process, which results in the formation of two acetic acid molecules. Each of these is then combined to coenzyme A, in order to form Acetyl-CoA.
The Krebs Cycle
By this time, the glycerol and the fatty acids get converted to Acetyl-CoA, making it ready to enter the Krebs Cycle. When the Acetyl CoA is broken down, carbon-dioxide and hydrogen are removed. The carbon-dioxide exits the body via the lungs for the second time and in the final step, the hydrogen moves on.
The Electron Transport Chain
The final step in the break down of food is called the Electron Transport Chain. The hydrogen molecules that were removed in the previous steps are transported to this chain. These molecules combine with oxygen to produce water. The final product of this reaction is energy, which in turn causes the formation of ATP.