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Paraffin waxes are mixtures of saturated n- and iso- alkanes, naphthenes, and alkyl- and naphthene-substituted aromatic compounds. A typical alkane paraffin wax chemical composition comprises hydrocarbons with the general formula C n H 2n+2, such as hentriacontane, C 31 H 64. The degree of branching has an important influence on the properties.
Sterols are steroids in which one of the hydrogen atoms is substituted with a hydroxyl group, at position 3 in the carbon chain. They have in common with steroids the same fused four-ring core structure. Steroids have different biological roles as hormones and signaling molecules.
For substances with an A- or α- prefix such as α-amylase, please see the parent page (in this case Amylase). A23187 (Calcimycin, Calcium Ionophore); Abamectine; Abietic acid
Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. [1] A sub-discipline of both chemistry and biology , biochemistry may be divided into three fields: structural biology , enzymology , and metabolism .
The atoms in molecules, crystals, metals and other forms of matter are held together by chemical bonds, which determine the structure and properties of matter. All bonds can be described by quantum theory, but, in practice, simplified rules and other theories allow chemists to predict the strength, directionality, and polarity of bonds. [4]
The simplest of molecules is the hydrogen molecule-ion, H 2 +, and the simplest of all the chemical bonds is the one-electron bond. H 2 + is composed of two positively charged protons and one negatively charged electron , which means that the Schrödinger equation for the system can be solved more easily due to the lack of electron–electron ...
Many species of the genus Primula and ferns, such as Cheilanthes, Pityrogramma and Notholaena, as well as many genera of Crassulaceae succulent plants, produce a mealy, whitish to pale-yellow glandular secretion known as farina that is not an epicuticular wax, but consists largely of crystals of a different class of polyphenolic compounds known as flavonoids. [5]
Consequently, hydrogen bonds between or within solute molecules dissolved in water are almost always unfavorable relative to hydrogen bonds between water and the donors and acceptors for hydrogen bonds on those solutes. [44] Hydrogen bonds between water molecules have an average lifetime of 10 −11 seconds, or 10 picoseconds. [45]