Match the type of bond with the role below:

Bond_type Role

(a) phosphodiester ___ links base to pentose in nucleotide
(b) N-glycosidic ___ joins adjacent nucleotides in one strand
(c) phosphate ester ___ joins complementary nucleotides in two

strands(d) hydrogen ___ difference between a nucleoside and a

nucleotide

(a) Phosphodiester -  joins adjacent nucleotides in one strand

(b) N-glycosidic - links base to pentose in nucleotide

(c) Phosphate ester - difference between a nucleoside and a  nucleotide

(d) Hydrogen - joins complementary nucleotides in two  strands

Explanation:

Phosphodiester linkage: One nucleotide in a strand of DNA/RNA is joined to another nucleotide with the help of a phosphodiester bond in which 3' carbon atom of one sugar molecule is linked to the 5' carbon atom of the adjacent nucleotide. It is a covalent bond which is formed between two sugars and a phosphate group so as to make sugar phosphate backbone of DNA and RNA.

N-glycosidic linkage: This bond exists between a sugar molecule and a nitrogenous base. For example: The first carbon of ribose sugar interacts with N1 of pyrimidine base so as to form N-glycosidic bond.

Phosphate ester: The difference between a nucleotide and a nucleoside is that a nucleoside lacks a phosphate group so it means a nucleoside will only have a sugar molecule attached to the nitrogenous base. In contrast to this, a nucleotide will have all three components i.e. a sugar molecule attached to the nitrogenous base along with that it will have a phosphate group attached to the sugar molecule through covalent phosphodiester bond. By all this we can easily infer that the only difference between a nucleotide and nucleoside is of phosphate ester.

Hydrogen bond: The complementary nucleotides in two anti parallel helices of DNA are joined with each other with the help of hydrogen bond, it is also known as Watson–Crick base pairing. A and T of two strands interact with the help of 2 hydrogen bonds while C and G interact with the help of 3 hydrogen bonds.

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