Lipid functions

The lipids play four types of functions:

• Reservation function. Lipids are the body's main energy reserve. When a gram of fat is oxidized, it produces 9.4 kilocalories, while protein and carbohydrates only produce 4.1 kilocalories / gram. As they are insoluble in water, they are stored in cells without affecting osmotic pressure.

• Structural function. Lipids (phospholipids, glycolipids, cholesterol) are the main constituents of the lipid bilayers of plasma membranes.

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• Biocatalyst function (vitamin and hormonal). Biocatalysts are substances that enable chemical reactions to occur in living beings. Lipid vitamins, steroid hormones and prostaglandins fulfill this function.

• Conveyor function. The transport of lipids from the intestine to its place of use is carried out by emulsifying the lipids thanks to bile acids and proteolipids, associations of specific proteins with triacylglycerides, cholesterol, phospholipids, etc., which allow their transport through the blood and lymph.

In addition, lipids have other functions:

• Protective function. Fat tissue protects vital organs and skeleton. Waxes protect from drying out.
• Thermal function. The adipose tissue insulates thermally helping to maintain body temperature.
• Water reserve function. In some desert animals, such as camels, dromedaries, etc., lipids act as a water reserve, since a lot of water is released during catabolic processes.