Mindblown: a blog about philosophy.

Vitamin C, water-soluble, carbohydrate-like substance that is involved in certain metabolic processes of animals. Although most animals can synthesize vitamin C, it is necessary in the diet of some, including humans and other primates, in order to prevent scurvy, a disease characterized by soreness and stiffness of the joints and lower extremities, rigidity, swollen and bloody gums, and hemorrhages…

Maltase, enzyme that catalyzes the hydrolysis of the disaccharide maltose to the simple sugar glucose. The enzyme is found in plants, bacteria, and yeast; in humans and other vertebrates it is thought to be synthesized by cells of the mucous membrane lining the intestinal wall. During digestion, starch is partially transformed into maltose by the pancreatic or salivary enzymes called amylases; maltase secreted by the intestine then…

Theobromine, diuretic drug and major alkaloidal constituent of cocoa. Theobromine is a xanthine alkaloid, a methylxanthine, as are caffeine and theophylline, but it differs from them in having little stimulatory action upon the central nervous system. The stimulant effect of cocoa results from the caffeine that it contains rather than from the theobromine.

Nucleoside, a structural subunit of nucleic acids, the heredity-controlling components of all living cells, consisting of a molecule of sugar linked to a nitrogen-containing organic ring compound. In the most important nucleosides, the sugar is either ribose or deoxyribose, and the nitrogen-containing compound is either a pyrimidine (cytosine, thymine, or uracil) or a purine (adenine or guanine). Nucleosides are usually obtained by chemical or enzymatic decomposition…

Adenine, organic compound belonging to the purine family, occurring free in tea or combined in many substances of biological importance, including the nucleic acids, which govern hereditary characteristics of all cells. Partial decomposition of ribonucleic and deoxyribonucleic acids yields mixtures from which the compounds adenylic acid and deoxyadenylic acid, respectively, may be separated. These acids, called nucleotides, are phosphate esters of adenosine and deoxyadenosine, which…

A carbon atom (and therefore the molecule in which it occurs) becomes oxidized if it loses electron density during a reaction or becomes reduced if it gains electron density. A carbon atom loses electron density when it bonds to a more electronegative atom and gains electron density when it bonds to a less electronegative atom. The most…

For much of organic chemistry, an acid may be defined as a compound that can transfer a proton (H+) to a base, and a base may be defined as any entity with an unshared pair of electrons (and therefore capable of accepting a proton). In acid-base reactions a proton is transferred from an acid to a…

The formation of a single bond between two molecules, or two parts of the same molecule, accompanied by the elimination of water (or another small molecule such as an alcohol) is a condensation reaction. Many polymerization reactions are condensation reactions. For example, the polymer nylon-6,6 is produced by the repeated condensation of hexanedioic acid with hexamethylenediamine.

The scission (or cleavage) of a molecule by reaction with water, with insertion of the elements of water into the final products, is called hydrolysis. An example is the acid-catalyzed hydrolysis of ethyl acetate. This reaction is typical of reversible reactions that do not go to completion. When one mole (the quantity with a weight…

The addition of one molecule to another to give a single new molecule constitutes an important class of reactions. Illustrative is the addition of chlorine to ethylene to give the dichloroethane used for the industrial production of vinyl chloride. Alcohols are commonly made by the addition of water to alkenes, as in the preparation of 2-propanol.