Nucleic acids are organic molecules that are essential for life. They are composed of nucleotides, which are made up of a sugar, a phosphate group, and a nitrogenous base. Exon is a 4-letter term that refers to a sequence of DNA or RNA that codes for a protein. DNA is a 3-letter acronym for deoxyribonucleic acid, which is a type of nucleic acid found in the nucleus of cells. RNA is a 3-letter acronym for ribonucleic acid, which is another type of nucleic acid found in the cytoplasm of cells. Both DNA and RNA are involved in the production of proteins.