As three nutrients in human body, sugar plays an inestimable and indispensable role in human body. 2. Sugar is one of the nutrients of human body, the source of energy and the important component of nerve, bone, eyeball cornea and vitreous body; It is an indispensable raw material for human tissues and cells, and it is also the only source of heat energy for the cranial nerve system.

Extended data:

Sugar (compound)

1. Sugar (compound).

Sugar is a polyhydroxy (two or more) aldehyde or ketone, which can become one of the organic compounds after hydrolysis. Chemically, because it is composed of carbon, hydrogen and oxygen, similar to the polymerization of carbon and water in the chemical formula, it is also called carbohydrate.

Second, biological function.

(1) provides energy. Plant starch and animal glycogen are both forms of energy storage. ?

(2) The carbon skeleton of substance metabolism provides the carbon skeleton for the synthesis of protein, nucleic acid and lipid.

(3) the skeleton of the cell. Cellulose, hemicellulose and lignin are the main components of plant cell walls, and peptidoglycan is the main component of prokaryotic cell walls.

(4) Recognition between cells and biomolecules. Oligosaccharide chains of glycoprotein on cell membrane surface participate in cell-to-cell recognition. Some cells contain sugar molecules or oligosaccharide chains on the surface of cell membrane, which form the antenna of cells and participate in cell communication. ABO blood group determinant on the surface of red blood cells contains fucose.