Answer to Question #198340 in Organic Chemistry for Aria

Question

Each nucleotide consists of three parts. These three parts can be represented diagrammatically, as shown below. Name and briefly describe the key chemical features for each of the '3-parts' of a nucleotide represented by each shape (circle, pentagon, rectangle)? [4 marks]

Write maximum 10-15 line response. 1 mark for correct name of all three parts; and 1 mark x 3 for each of the three descriptions.

Answer 1

A nucleotide has three components - nitrogenous base, a pentose sugar ribose in case of RNA and deoxyribose for DNA) and a phosphate group. There are two types of nitrogenous bases - Purines (Adenine and Guanine) and Pyrimidines (Cytosine and Thymine).

A nitrogenous base is linked to the pentose sugar through a N-glycosidic linkage to form a nucleoside.

When a phosphate group is linked to 5 -OH of a nucleoside through phosphodiester linkage, a corresponding nucleotide is formed. The nucleotides are linked through 3-5 phosphodiester linkage to form a dinucleotide.