DNA and RNA are nucleic acids and they form the building blocks of heredity and genetic information. DNA stands for deoxyribonucleic acid. It is composed of a series of nucleotides which consist of a phosphate group, a cyclic ribose sugar, and a nitrogenous base. It is found in the nucleus of cells. RNA stands for ribonucleic acid and has largely the same structure as DNA. It is utilized in protein synthesis. There are two key structural differences between DNA and RNA. RNA has an extra hydroxyl group (OH) on the #2 carbon of the ribose sugar ring. DNA has no hydroxyl group there (hence the term deoxy). The other major structural difference is in the nitrogenous bases. Both molecules use adenine, guanine, and cytosine. DNA uses thymine while RNA uses uracil.