Essential concepts and techniques in molecular biology

Abstract

Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are macromolecules that convey genetic information. Both DNA and RNA are made up of nucleotides, molecules that in turn are composed of a nitrogenous base, a sugar, and one or more phosphate groups. There are five nitrogenous bases found in nucleic acids: adenine, guanine, cytosine, thymine, and uracil. Adenine, guanine, and cytosine are found in both DNA and RNA; thymine is found only in DNA and uracil is found only in RNA. A second difference between DNA and RNA is the sugars that are incorporated into the nucleotides. The sugar in the nucleotides of DNA is deoxyribose, RNA nucleotides contain ribose. Finally, DNA molecules are double-stranded, while RNA molecules are usually single-stranded.