Structure of Nucleotides and DNA

The double helix is ​​not twisted and the corresponding bracket is zipper type. Hydrogen bond cleavage between bases forms hydrogen bonds with floating nucleotides with nitrogen-containing bases. This is due in part to complementary base pairing. When new nucleotides are bound together by enzyme DNA polymerase, they form a complete chain opposite the original strand. Finally, all nucleotides are joined using DNA polymerase to form a complete polynucleotide chain.

Watson and Crick proposed a DNA double helix model. A DNA molecule is a polymer of nucleotides. Each nucleotide consists of a nitrogen-containing base, a pentose sugar (deoxyribose) and a phosphate group. DNA has four nitrogen-containing bases, two purines (adenine and guanine) and two pyrimidines (cytosine and thymine). The DNA molecule consists of two chains. Each chain consists of nucleotides covalently linked to each other between one phosphate group and the next deoxyribose sugar. We extend the base from this backbone. The base of one chain is hydrogen bonded to the base of the other chain. Adenine is always bound to thymine, and thymine is always bound to guanine. By this combination, the two strands are spirally wound together in a shape called a double helix. Ribonucleic acid (RNA) is a second nucleic acid found in cells. RNA is a single-stranded polymer of nucleotides

Nucleic acids include deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). They are very similar in structure because they are all polymers with monomeric units as nucleotides. Nucleotides consist of pentose groups, phosphate groups and nitrogen-containing bases. In DNA and RNA, these bases can be one of four types; otherwise, like RNA, all nucleotides of DNA are identical. DNA and RNA differ mainly in three respects. One is DNA, pentose is deoxyribose, and RNA is ribose. These sugars will differ by oxygen atom by chance. The second difference is that DNA is usually double-stranded and forms a double helix discovered by the team of Watson and Click in the 1950's, but RNA is single-stranded. Third, DNA contains nitrogen-containing bases adenine (A), cytosine (C), guanine (G), and thymine (T), but uracil (U) instead of thymine It is included.

DNA exists in a double-stranded structure and the two chains are coiled together to form a characteristic double helix. Each DNA strand is a chain of four nucleotides. Nucleotides in DNA include deoxyribose, phosphate and nucleobases. The four nucleotides correspond to four nucleobases, adenine, cytosine, guanine and thymine, usually abbreviated as A, C, G and T. Adenine and guanine are purine bases, while cytosine is purine base. And thymine is pyrimidine. These nucleotides form phosphodiester bonds, which produce the phosphate-deoxyribose backbone of the DNA duplex, with the nucleobases facing inward (ie toward the opposite strand). Nucleobases match between chains by hydrogen bonding to form base pairs. Adenine pairs with thymine (two hydrogen bonds) and guanine pairs with cytosine (three hydrogen bonds)