Classified according to chemical molecular structure: monosaccharides, oligosaccharides (oligosaccharides), polysaccharides, and complex sugars.
1. Monosaccharide: The simplest type of sugar structure. Monosaccharide molecules contain many hydrophilic groups, are easily soluble in water, and are insoluble in organic solvents such as ether and acetone. Simple monosaccharides It is generally a polyhydroxy aldehyde or polyhydroxy ketone containing 3-7 carbon atoms, and its constituent elements are C, H, O glucose, fructose, galactose, etc.
Glucose is the main energy substance for life activities, ribose is the component of RNA, and deoxyribose is the component of DNA. The molecular formulas of glucose and fructose are: C6H12O6. They are isomers.
2. Oligosaccharides (oligosaccharides): They are polymerized from 2-10 monosaccharide molecules. After hydrolysis, they can generate monosaccharides, including disaccharides, trisaccharides, tetrasaccharides, etc.
1. Disaccharide: Disaccharide is a glycoside formed by the dehydration of two molecules of monosaccharide, and the aglycone is another molecule of monosaccharide. The disaccharide is hydrolyzed to form two molecules of monosaccharide. Such as lactose, sucrose, maltose. Sucrose and maltose can be hydrolyzed into simple sugars for energy. Their molecular formulas are: C12H22O11. Also belong to isomers.
2. Trisaccharide - three molecules of monosaccharide are generated after hydrolysis. Like raffinose. Starch is a storage substance, cellulose is a component of the cell wall, and glycogen is an energy storage substance.
3. Polysaccharide - composed of more than 10 monosaccharide molecules. After hydrolysis, multiple monosaccharides or oligosaccharides can be generated. According to whether the composition of the monosaccharides generated after hydrolysis is the same, it can be divided into:
1. Homopolysaccharides - Homopolysaccharides are composed of one type of monosaccharide, and the same type of monosaccharides are generated after hydrolysis. Such as gum arabic, glycogen, starch, cellulose, etc. The expressions of starch and cellulose are (C6H10O5)n. But they are not isomers because their n numbers are different. Among them, starch nlt; cellulose n.
2. Heteropolysaccharides - Heteropolysaccharides are composed of a variety of monosaccharides, and different types of monosaccharides are generated after hydrolysis. Such as mucopolysaccharides, hemicellulose, etc.
4. Complex carbohydrate (glycoconjugate). The product of combining the reducing end of carbohydrates with proteins or lipids.
Extended information:
1. The main biological functions of carbohydrate compounds are:
1. As bioenergy;
2 , as a carbon source for the biosynthesis of other substances;
3. As structural substances of organisms;
4. Glycoproteins, glycolipids, etc. have cell recognition, immune activity, etc. Physiologically active functions.
2. The role of sugar
1. Eating sugar can be a good source of energy. Many of our athletes often cannot eat food that is too filling before participating in strenuous exercise, but they have to replenish energy, so they choose sugar to replenish energy, because only a little bit of sugar can release a lot of energy. It is a high-energy food.
2. It can increase blood pressure. Many people suffer from hypotension and don’t know what to do when they feel dizzy. I can tell you that sugar is one of the best substances for raising blood pressure. So when you feel that your blood pressure is too low, you can eat some sugar in moderation. food type.
3. Sugar can reduce a person’s stress. Many times people will choose to hold sugar in their mouths when they feel stressed, so many athletes will choose to chew gum in their mouths when participating in some important competitions.
Reference: Baidu Encyclopedia-Saccharides