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
Petroselinic acid in Garryaceae. In Picramniaceae, petroselinic acid is accompanied by tariric acid. In addition, petroselinic acid has been found in minor amounts in several fats of plant and animal origin, including in human sources. The occurrence of petroselinic acid as the major fatty acid is used in chemosystematics as a proof of a close relationship of several families within the Apiales as well as within the Garryales. Besides petroselinic acid, oleic acid has been shown to be present in all cases examined. Fatty acids mostly occur as their esters, commonly the triglycerides, which are the greasy materials in many natural oils.