Chapter 26, Problem 26.25UKC

Interpretation Introduction

Interpretation:

The groups found on the exterior of the DNA double helix; charge of the histones; amino acids abundant in histones has to be discussed.

Concept Introduction:

Composition of nucleic acid: Nucleic acid is a polymer of nucleotides. Each nucleotide has three parts: a sugar, a nitrogenous base, and a phosphate group. Two nucleotides are joined by phosphate diester linkage where a free phosphate on 5’ carbon of one nucleotide and a free –OH group on 3’ carbon of another nucleotide.

Nitrogenous bases: Five types of nitrogenous bases (has unique one-letter code A, G, T, U, and C) are derived from two parent compounds called purine and pyrimidine. The purine derivatives are Adenine and Guanine are two fused nitrogen containing rings. The pyrimidine derivatives are Thymine, Cytosine, and Uracil are only one nitrogen containing six-membered ring.  Adenine, Guanine, Thymine, and Cytosine are the nitrogenous bases present in DNA. Adenine, Guanine, Cytosine and Uracil are the nitrogenous bases present in RNA.