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
Cupboard love by physiologist, Ivan Pavlov. It supports assumptions that form the foundation of behaviorism. These basic ideas suggest that all learning occurs through interactions within the environment, and that environment shapes behavior. Various similarities exist between cupboard love and classical conditioning. Pavlov, known for Pavlov's dog experiment, discovered that his dog would salivate at the sound of a bell, associating the ringing with food. Eventually, the dog would salivate each time he heard the bell ring. When there was no food, the dog would still show affection to Pavlov in an attempt to be fed. Similarly, the cupboard love theory suggests