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
Hippocrates the year 460 BC on the Greek island of Kos; other biographical information, however, is likely to be untrue. Soranus of Ephesus, a 2nd-century Greek physician, was Hippocrates' first biographer and is the source of most personal information about him. Later biographies are in the "Suda" of the 10th century AD, and in the works of John Tzetzes, Aristotle's "Politics", which date from the 4th century BC. Soranus wrote that Hippocrates' father was Heraclides, a physician, and his mother was Praxitela, daughter of Tizane. The two sons of Hippocrates, Thessalus and Draco, and his son-in-law, Polybus, were his students. According