Nucleic acids

Nucleic acids are the third and final class of biomolecule studied in this chapter, and are distinguished from carbohydrates and proteins by their unique biological role: they are the molecules responsible for storing and transmitting an organism's GENETIC information. One of the most remarkable properties any living cell has is its ability to produce faithful replicas of itself across thousands of successive generations -- and this is possible only because a certain kind of information, the genetic information specifying how to build and run the organism, is copied and passed on essentially unchanged from each generation of cells to the next; nucleic acids are precisely the molecules that accomplish this transfer. There are two distinct types of nucleic acid: ribonucleic acid (RNA), found predominantly in the fluid interior (cytoplasm) of living cells, and deoxyribonucleic acid (DNA), found predominantly within the nucleus of living cells. Understanding the detailed chemical STRUCTURE of these two nucleic acids -- the goal of the rest of this section -- is the essential …