Unit 12
DNA and RNA

Overview

Of all areas of biochemistry, deoxyribonucleic acids (DNA) and ribonucleic acids (RNA) are generating the most research excitement. The study of DNA and RNA, commonly called “molecular genetics,” forms the basis of genetics and explains the production of enzymes. Enzymes control all biological processes, so the study of DNA and RNA brings us as close to understanding life as chemistry allows.

In Unit 5, we introduced the structure of nucleic acids. In this unit we describe how DNA and RNA work, emphasizing the three-dimensional structure of these molecules, and discussing the importance of the three-dimensional structures in DNA and RNA function. We also describe how DNA and RNA synthesis is controlled, and how DNA, in particular, is protected from chemical reaction. Finally, we explain the differences between DNA and RNA, and the biochemical consequences of these differences. In Unit 13 (the final unit), we discuss protein synthesis, which is under the direction of RNA.

Unit 12 is divided into three lessons:

1. DNA and RNA—Chemistry and Structure
2. DNA Replication and Repair—Information Storage
3. RNA Replication—Information Transmission

Objectives

After completing this unit, you should be able to

1. explain the chemical differences between DNA and RNA.
2. describe DNA replication.
3. explain the major differences and similarities between the synthesis of DNA and that of RNA.

Glossary

Please review the glossary for Unit 5.