What are the basic characteristics of dna double helix structure?
The main features of dna regular double helix structure are as follows:
Dna molecule is a double helix structure composed of two anti-parallel deoxynucleotide chains.
Deoxyribose and phosphoric acid in dna molecules are alternately connected and arranged on the outside to form the basic skeleton, and bases are arranged on the inside.
The bases on the two strands of dna molecules are connected by hydrogen bonds to form base pairs, which follow the principle of base complementary pairing.
What are the basic characteristics of DNA double helix structure?
The double helix structure of DNA includes three points:
The 1. double helix structure consists of two long deoxynucleotide chains which are antiparallel.
2. Phosphoric acid and deoxyribose are alternately arranged on the outside to form a skeleton, and bases are arranged on the inside.
3. The bases of two chains can form base pairs through hydrogen bonds, and the base pairs follow the law of complementary base pairing.
Deoxyribonucleic acid, also known as deoxyribonucleic acid, is a biomacromolecule, which can form genetic instructions to guide biological development and life function operation. Its main function is information storage, which can be compared to "blueprint" or "menu". The instructions contained therein are needed to construct other compounds in the cell, such as protein and RNA. DNA fragments with protein codes are called genes.
Characteristics of DNA double helix structure
Characteristics of dna double helix structure;
The two complementary strands of dna are antiparallel.
② The hydrophilic skeleton composed of deoxyribose and phosphoric acid is on the outside of the helical molecule, while the hydrophobic base pair is on the inside of the helical molecule. The basal plane is perpendicular to the helix axis, the helix rotates well 10 base pairs, and the pitch is 3.4nm, so the interval between adjacent basal planes is 0.34nm, and there is a 36? Angle.
③ There is a big groove and a small groove on the surface of ③dna double helix, through which protein molecules can recognize bases.
(4) The two dna strands are bound together by hydrogen bonds formed between bases. According to the characteristics of base structure, only purine and pyrimidine can be paired, that is, A and T can be paired to form two hydrogen bonds; G and c pair to form three hydrogen bonds. So the connection between g and c is relatively stable.
⑤dna double helix structure is relatively stable. Maintaining this stability mainly depends on the hydrogen bond between base pairs and the accumulation force of bases.
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What are the characteristics and biological functions of DNA double helix structure?
The following is my own summary based on what I wrote in our book, hoping to help you:
The double helix structure of DNA has the following characteristics: 1, DNA is an antiparallel complementary double-stranded structure, and its two polynucleotide chains are antiparallel in spatial arrangement, with bases on the inside and hydrophilic deoxyribose and phosphate groups on the outside, and the bases are complementary and paired in A-T and G-C ways; 2.DNA double-stranded is a right-handed spiral structure, and the two polynucleotide chains of DNA are anti-parallel and wound around the same central axis, showing a right-handed spiral; Hydrophobic force and hydrogen bond maintain the stability of DNA double helix, horizontal stability is maintained by hydrogen bond between bases, and vertical stability is maintained by hydrophobic stacking force between base planes.
Biological function of DNA: DNA is the genetic material and the carrier of genetic information.
The evidence is as follows: 1, DNA
Distribution in chromosomes is the main component of chromosomes, and chromosomes are directly related to heredity. 2. The DNA content of somatic cells is twice that of germ cells, and the content is very stable. 3.DNA metabolism is stable, and it is not affected by nutritional status, age and other factors. 4. The physical and chemical factors acting on DNA will cause the change of genetic characteristics, which has been proved by Avery's transformation experiment with pneumococcus in 1953.