Water (85%~90%), inorganic salt (1%~1.5%)

Protein (7%~10%), lipids (1%~2%), carbohydrates and nucleic acids (1%~1.5%)

Water is a good solvent within cells. Many substances can dissolve in water, providing a liquid environment for cells, transporting nutrients and metabolic waste, and participating in biochemical reactions.

Water, which is bound by other substances in the cell (such as proteins) and cannot flow freely, is the main component of the cell.

The content of inorganic salts in cells is very small, accounting for about 1% of the weight of the cells. Most of them exist in the form of ions in the cells.

The main component of some complex compounds within cells

Participate in maintaining normal metabolic activities of cells

Maintain the stability of physical and chemical properties of living organisms

five carbon sugar

six carbon sugar

Sucrose: Glucose Fructose

Maltose: Glucose Glucose

Lactose: Glucose Galactose

Starch (hydrolysis product is glucose)

Cellulose

glycogen

Chitin (chitin) (C8H13O5N)n

Contains only three elements: C, H, and O. It is formed by the reaction of three molecules of fatty acids and one molecule of glycerol. An important energy storage substance in cells, it has the functions of heat preservation, buffering, decompression, etc. It can protect internal organs and can be hydrolyzed into glycerol and fatty acids.

In addition to C, H, O, it also contains P and even N elements Forms an important part of the cytoplasmic membrane, organelle membrane and nuclear membrane

sex hormones

Vitamin D

cholesterol

Essential amino acids: phenylalanine, methionine, lysine, threonine, tryptophan, leucine, isoleucine, valine

The basic unit of protein is amino acid. Each amino acid molecule contains at least one amino group (NH2) and one carboxyl group (COOH), and both have an amino group and a carboxyl group connected based on the same carbon atom. This carbon atom is also separately Attached to a side chain group (R) and a hydrogen atom

①Catalysis: Almost all biochemical reactions require enzyme catalysis, and the vast majority of enzymes are proteins. ②Transportation: Hemoglobin transports oxygen; lipoproteins transport fat from the liver to other parts of the body along with the blood flow ③Exercise: Some proteins in muscles are related to muscle contraction and relaxation. ④Defense: Antibodies are a type of protein with immune function; coagulation factors are a type of protein that can protect injured blood vessels. ⑤Regulation: Growth hormone is a protein that can regulate the growth and development of the human body. ⑥Structure: Protein is the main substance that makes up DNA.

Basic unit: deoxynucleotide

Nucleotide

base

Five-carbon sugar: deoxyribose

Basic unit: ribonucleotide

Nucleotide

base

Five-carbon sugar: ribose

DNA: Mainly distributed in the nucleus, with a small amount present in mitochondria and chloroplasts

RNA: mainly distributed in the cytoplasm

Both DNA and RNA are distributed in the cytoplasm of cells and nuclei, but their contents are different.

DNA: mainly distributed in the nucleoid, with a small amount present in the cytoplasm

RNA: mainly distributed in the cytoplasm

A virus contains only one nucleic acid

DNA, RNA, 8 kinds of nucleotides, 5 kinds of bases (A, T, G, C, U), the genetic material is DNA

DNA viruses (phages, etc.)

RNA viruses (tobacco mosaic virus, SARS virus, etc.)