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Phosphatidylethanolamine (PE) is a class of phospholipids found in biological membranes. [1] They are synthesized by the addition of cytidine diphosphate-ethanolamine to diglycerides, releasing cytidine monophosphate. S-Adenosyl methionine can subsequently methylate the amine of phosphatidylethanolamines to yield phosphatidylcholines.
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
Theoretical chemistry requires quantities from core physics, such as time, volume, temperature, and pressure.But the highly quantitative nature of physical chemistry, in a more specialized way than core physics, uses molar amounts of substance rather than simply counting numbers; this leads to the specialized definitions in this article.
Physical chemistry, in contrast to chemical physics, is predominantly (but not always) a supra-molecular science, as the majority of the principles on which it was founded relate to the bulk rather than the molecular or atomic structure alone (for example, chemical equilibrium and colloids).
A uniform polymer (often referred to as a monodisperse polymer) is composed of molecules of the same mass. [5] Nearly all natural polymers are uniform. [6] Synthetic near-uniform polymer chains can be made by processes such as anionic polymerization, a method using an anionic catalyst to produce chains that are similar in length.
Phosphatidylethanolamine N-methyltransferase (abbreviated PEMT) is a transferase enzyme (EC 2.1.1.17) which converts phosphatidylethanolamine (PE) to phosphatidylcholine (PC) in the liver. [ 5 ] [ 6 ] [ 7 ] In humans it is encoded by the PEMT gene within the Smith–Magenis syndrome region on chromosome 17 .
Examples of intensive properties include temperature, T; refractive index, n; density, ρ; and hardness, η. By contrast, an extensive property or extensive quantity is one whose magnitude is additive for subsystems. [4] Examples include mass, volume and Gibbs energy. [5] Not all properties of matter fall into these two categories.
Chemical classification systems attempt to classify elements or compounds according to certain chemical functional or structural properties. Whereas the structural properties are largely intrinsic, functional properties and the derived classifications depend to a certain degree on the type of chemical interaction partners on which the function is exerted.