Chapter 5, Problem 8Q

Summary Introduction

To explain: The melting nature of the three given DNA strands.

Concept introduction: A DNA molecule is made up of a helical strand composed of nucleotide base pairs carrying the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms. When two strands of DNA come together, they form hydrogen bongs between the complementary bases present in each chain. Bond formation releases considerable amount of energy and thus contributes to an increase in entropy of the DNA molecule. Adenine and thymine residues are bonded by two hydrogen bonds between them, whereas cytosine and guanine bases are by three hydrogen bonds. Therefore, the energy required for the dissociation of two strands of a DNA primarily depends on the number of A-T and C-G base pairs.