The nucleotide present in DNA is cytosine, together with a phosphate group and deoxyribose sugar.
Further Explanation:
DNA is composed of a long chain of polymer consisting of repeating units known as nucleotides. The structure of DNA includes two chains coiled around one another, forming a helical structure. The interaction between the nucleotides from both the strands holds the helix tightly. A sugar molecule linked to a base is called a nucleoside, whereas a nucleoside attached to a phosphate group is termed as a nucleotide. The multiple nucleotides joined together, forming a polymer is known as a polynucleotide. The DNA strand has a backbone containing alternation residues of sugar and phosphate. The sugar present in the DNA is a pentose sugar or 2-deoxyribose. The phosphate group bound to the sugar molecule forms phosphodiester bonds with the adjacent sugar rings. In the DNA structure, both the strands are antiparallel to each other, which mean the sequence of nucleotides present in strand one is opposite to the nucleotide sequence in strand 2. The ends of each strand of DNA are termed as 5’ (five prime) end and 3’ (three prime) end. The 5’ end has a phosphate group at the terminal while the 3’ end comprises the hydroxyl group.
The DNA is stabilized by base- stacking interaction, which occurs among the aromatic bases and the hydrogen bonds that forms between the nucleotides. The bases present in DNA are categorized as purines and pyrimidines. Guanine (G) and adenine (A) are the two purines, while thymine (T) and cytosine (C) come under pyrimidines. When a base such as a cytosine combines with a sugar and phosphate to form a complete nucleotide, it is called as cytidine monophosphate. The base pairing occurs between the purine and the pyrimidine of the opposite strands to stabilize the helical structure.
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Answer Details:
Grade: High School
Chapter: DNA and its Structure
Subject: Biology
Keywords:
DNA, double-helical structure, nucleosides, nucleotides, sugar, deoxyribose, phosphate group, hydrogen bonds, phosphodiester bond, base-stacking interactions, purines, pyrimidines, adenine, guanine, thymine, cytosine.
