The Main Role Of Fatty Acids

Fatty acids often combine with other substances to form esters, and fatty acids in free form are rare in nature.
When people encounter hunger or stress, hormones activate lipase in fat cells, converting stored triglycerides back into fatty acids and glycerol, which are then released into the blood for use. Except for brain cells, all cells in the body adapt themselves to using fatty acids when they are hungry and lack energy. Fatty acids can be converted into the energy form of ATP just like glucose. In fact, hormones that stimulate triglyceride cleavage are ineffective in the brain. Since the human brain does not have the ability to use fatty acids like other parts of the body, it can only use glucose. Glycerol, another product of triglyceride cleavage, circulates to the liver, which converts it into glucose through another biochemical pathway to nourish the brain. In this way, when nutrients are scarce, other parts of the body can rely on fatty acids, while the brain can only rely on the glucose it needs.
Animals can synthesize the saturated fatty acids and unsaturated fatty acids such as linoleic acid that only contain one double bond. Multi-double-bond fatty acids containing two or more double bonds must be obtained from plants and are called essential fatty acids. Among them, linolenic acid and linoleic acid are the most important. In most oil-rich foods, about half of the calories are provided by fats and oils. Natural fats and oils are usually a mixture of various esters formed by more than one fatty acid and glycerol. The functions of these fatty acids are as follows.