Acetyl group known as paracetamol), and acetylsalicylic acid (better known as aspirin). The introduction of an acetyl group into a molecule is called acetylation. In biological organisms, acetyl groups are commonly transferred from acetyl-CoA to other organic molecules. Acetyl-CoA is an intermediate both in the biological synthesis and in the breakdown of many organic molecules. Acetyl-CoA is also created during the second stage of cellular respiration, the Krebs Cycle, by the action of pyruvate dehydrogenase on pyruvic acid. Histones and other proteins are often modified by acetylation. For example, on the DNA level, histone acetylation by acetyltransferases (HATs) causes an expansion of
Picric acid Picric acid Picric acid is an organic compound with the formula (ON)CHOH. Its IUPAC name is 2,4,6-trinitrophenol (TNP). The name "picric" comes from the Greek πικρός ("pikros"), meaning "bitter", reflecting its bitter taste. It is one of the most acidic phenols. Like other highly nitrated organic compounds, picric acid is an explosive, hence its primary use. It has also been used in medicine (antiseptic, burn treatments) and dyes. Picric acid was probably first mentioned in the alchemical writings of Johann Rudolf Glauber. Initially, it was made by nitrating substances such as animal horn, silk, indigo, and natural resin, the synthesis