Composition: mainly composed of three elements: carbon, hydrogen and oxygen.
Sugar compounds include monosaccharides, polymers and derivatives of monosaccharides.
Monosaccharide molecules are aldehydes or ketones with multiple hydroxyl groups.
Chemical concept of carbohydrate compounds: monosaccharide is polyhydroxyaldehyde or polyhydroxyketone and its cyclic hemiacetal or derivative. Polysaccharides are polymers of monosaccharide condensation.
General molecular formula: Cn(H2O)m
However, not all sugars conform to this general formula, and not all sugars conform to this general formula.
This is just a general formula for most sugars.
oil
lipin
A large class of organic compounds insoluble in water but soluble in organic solvents. Also known as lipids. Include neutral fats, phospholipids, glycolipids, sphingolipids, terpenoids, steroids, waxes, etc. Different lipids have different chemical compositions and structures. There are simple chain molecules composed of carbon, hydrogen and oxygen; There are also complex branched-chain structures and cyclic structures with diverse components.
According to its structural components, it can be divided into: ① simple lipids. Namely esters of fatty acids with various alcohols. Include acyl glycerides and waxes. ② Complex lipid. That is, fatty acid esters containing other chemical groups. Include phospholipids, glycolipids and their derivatives. ③ unsaponifiable lipids. That is, lipids without fatty acids. Include terpenoids, steroids, etc. In addition to the above lipids, there are hybrid molecules such as lipoproteins and lipopolysaccharides.
Lipids have many biological functions. Fatty acid is an important energy source of organisms, which stores energy in the form of triacylglycerol (fat) and is also the building block of many structural lipids. Subcutaneous fat has the protective effect of preventing mechanical damage and heat loss in the body. Phospholipids, a small amount of glycolipids and cholesterol are important structural components of biofilm. Glycolipids, as cell surface substances, are closely related to cell surface recognition, species specificity and tissue immunity. In addition, there are two important unsaponifiable lipids (which do not contain bound fatty acids and cannot be saponified by alkali, that is, hydrolyzed substances): terpenoids and steroids, which have various biological functions such as hormones, vitamins and coenzymes respectively.