Chapter 23, Problem 80A

Interpretation Introduction

Interpretation:

The type of bonding and attraction that link the monomers together in DNA molecule should be described.

Concept introduction:

Nucleic acids are large biomolecules or biopolymers which are essential to different forms of file. Two major types of nucleic acid which are found in living organisms are: DNA and RNA.

DNA stands for deoxyribonucleic acid which contains five carbon sugar, a nitrogen base and a phosphate group. It stores the biological information or gene information in a sequence of four bases of nucleic acid: Adenine, cytosine, thymine and guanine. DNA has a structure of double helix. It also stores the replicate genetic information.

Answer to Problem 80A

The type of bonding and attraction that link the monomers together in DNA molecule is hydrogen bonding.

Explanation of Solution

In the structure of DNA, two nucleotides chain are present in the form of spiral structure that is helix. The double helix is held together by two types of bond that are hydrogen bonds and covalent bonds. Covalent bonds are present within both linear strand and form strong bond between bases, phosphate groups and sugars. The intermolecular forces that are hydrogen bonds are present between the two strands which hold the bases (pairing) present in DNA molecule with each other in the centre of helix. Hydrogen bonding is formed due to the interaction between negative charge of oxygen atom (one base) and positive charge of hydrogen atom of another base. This hydrogen bonding is weak in comparison to covalent bon individually but strong collectively.

Thus, the type of bonding and attraction that link the monomers together in DNA molecule is hydrogen bonding.