1, fatty [zh and fá ng] organic compounds, which exist in subcutaneous tissues and plants of humans and animals. Fat can supply a lot of heat energy needed by human body.

2. Oil [yóu zhρ] refers to the ester formed by higher fatty acids and glycerol in organisms. The liquid at room temperature is called oil, and the solid is called fat. The former is vegetable oil and peanut oil, while the latter is lard and butter. After hydrogenation, cottonseed oil can be converted into solid artificial fat, which can be used in food and soap making. Oil, protein and sugar are the three main components of human nutrition.

3. Agar [Qió ng zhΡ] is a gelatinous product extracted from some red algae plants, which is mainly used as a gel and stabilizer for culture medium and food.