1, fat
Function: good energy storage substance in cells; Reduce heat loss and keep body temperature constant; Reduce the friction between internal organs and have the function of buffering external pressure.
2. Phospholipids
Function: It is an important part of cell membrane, mitochondrial membrane, chloroplast membrane and other structures-all cells contain phospholipids.
3. Sterol
(1) cholesterol. Function: It is an important component of cell membrane and also participates in lipid transport in human blood.
(2) sex hormones. Function: Promote the development of reproductive organs and the formation of hermaphroditic germ cells, and stimulate and maintain the secondary sexual characteristics of hermaphroditic animals.
(3) D. Function: Promote the absorption and utilization of calcium and phosphorus by people and animals.
Lipid function
store energy
It is the best way to store energy, such as triglycerides of animals and oilseeds. By comparing the following data, we can draw a conclusion:
Comparison of two energy substances (sugar and lipid) in the body
Energy supply per unit weight: sugar 4. 1 kcal/g, fat 9.3 kcal/g.
Storage capacity: 1 glycogen or starch: 2 water, while fat is relatively pure and much smaller.
In the order of utilization: sugar is consumed first, and then lipid is consumed. So many weight loss/slimming principles, such as breaking the valley, all come from this.
Biofilm skeleton
Liquid mosaic model of cell membrane: phospholipid diester layer, cholesterol, protein, glycolipid, glycerophosphate and sphingomyelin.
Electrical and thermal insulators
Animal adipose tissue has protective functions such as heat preservation and mechanical stress prevention, and vegetable wax can prevent water evaporation.
Electrical insulation: sheath cells of nerve cells, sheath of electric wires, and short circuit of nerves.
Insulation: keep warm in winter, penguins, polar bears, etc.