DNA DNA Deoxyribonucleic acid (; DNA) is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses. DNA and ribonucleic acid (RNA) are nucleic acids; alongside proteins, lipids and complex carbohydrates (polysaccharides), nucleic acids are one of the four major types of macromolecules that are essential for all known forms of life. The two DNA strands are also known as polynucleotides as they are composed of simpler monomeric units called nucleotides. Each nucleotide is composed
Carboxylic acid the electron-withdrawing effect of the carbonyl bond, which makes the terminal oxygen-hydrogen bond weaker and thus makes acid dissociation more favorable (lowers pKa). Carboxylic acids can be seen as reduced or alkylated forms of the Lewis acid carbon dioxide; under some circumstances they can be decarboxylated to yield carbon dioxide. Carboxylic acids are commonly identified using their trivial names, and usually have the suffix "-ic acid". IUPAC-recommended names also exist; in this system, carboxylic acids have an "-oic acid" suffix. For example, butyric acid (CHCOH) is butanoic acid by IUPAC guidelines. The "-oic acid" nomenclature detail is based on the