Distribution in plants and animals

Carbonic anhydrase was the first Zn metallo-enzyme to be discovered (1940) and in its several forms is widely distributed in plants and animals. It catalyses the equilibrium reaction ... 

Lipoxygenases, which catalyse the oxidation of unsaturated fatty acids containing the cis,cis-l,4-pentadiene moiety to the corresponding 1 -hydroperoxy-f rans,ds-2,4-diene (Table 2.3), are widely distributed in plants and animals. The mammalian... 

Hydroxytryptamine is widely distributed in plant and animal tissues, mast cells, platelets, the enterochromaffin cells located throughout the gastrointestinal tract, and in certain regions of the brain. It is also present in the venoms and stings. Some fruits such as bananas, pineapples, tomatoes and plums contain considerable amount of 5-HT. 

In 1886, MacMunn 12) discovered the respiratory pigment, myohema-tin, which was widely distributed in plant and animal tissues. This important observation attracted little attention at the time of its publication and became effectively lost in the literature 13). In 1925, Keilin 14)... 

Derivation Widely distributed in plants and animals both free and combined with proteins. 

Sterol. A steroid alcohol. Such alcohols contain the common steroid nucleus, plus an 8- to 10-car-bon-atom sidechain and a hydroxyl group. Sterols are widely distributed in plants and animals, both in the free form and esterified to fatty acids. Cholester-... 

The average K+ content of the human body is 40 mEq/kg. K+ occurs mainly in intracellular space. It is required for carbohydrate metabolism, and increased cellular uptake of K+ occurs during glucose catabolism. K" " is widely distributed in plant and animal foods, the human requirement being about 4 g/day. Insulin and catecholamines promote a shift of K+ into the cells. Excess K+ is excreted in the urine, a process regulated by aldosterone. 

Iron distribution in plants and animals is tightly regulated to counteract deficiency symptoms in situations of scarce supply (see Chapter 13.1.5). An iron-replete adult male organism contains about 4 g of iron, approximately 60% of which is used in... 

Sources. Pantothenic acid is widely distributed in plant and animal food sources, where it occurs in both bound and free forms. Rich sources of the vitamin include organ meats (liver, kidney), egg... 

Polysaccharides are widely distributed in plants and animals. They are present both as structural materials, for example, cellulose, and as food storage compounds such as starch and glycogen. 

Linoleic add A - Loctadecadienoic acid, CH3-(CH2)4-CH = CH-CH2-CH=CH-(CH2)r-COOH, an essential fatty acid, M, 280.44, m.p. S C, b.p., 202°C.L.a. is widely distributed in plants and animals It occurs as an esterified component in many fats and oils, and it is found in phosphatides It is an essential dietary constituent for mammals... 

Waxes are widely distributed in plants and animals, where they often have a protective function. The hydrophobic nature of the wax coating reduces water losses caused by transpiration in plants, and provides wool and feathers with waterproofing in... 

Enzymes which hydrolyze maltose and a-glucosides are widely distributed in plant and animal products and microorganisms 67). The products which have been studied are crude and often only slightly active mixtures of various enzymes. Such preparations have been utilized for testing the action of a-glucosidase on sucrose. Since they may contain... 

Monoterpenoids are widely distributed in plant and animal kingdoms, both terrestrial and marine (379). Lists of their occurrence in higher plants have been compiled (19, 155, 175, 275, 395, 396). Thble 8.1.2 lists plant families that are, by far, the most prolific in accumulating monoterpenoids. a-Pinene, cineol and limonene are the most widely distributed monoterpenoids. 

Strictly (3,(3-carotene, is the most important of the provitamins A and is widely distributed in plants and animals (Merck Index, 1996). As a dyestuff it may be derived from various Cuscuta species (C. tinctoria Mart., C. americana Lin. and C. odontolepis Engehnann), where it occurs almost always together with chlorophyll (q.v.). 

Niacin is categorized as a vitamin because its precursor, tryptophan, is an essential amino acid, so the human synthesis of niacin is dependent upon diets. Preformed niacin is widely distributed in plant and animal foods. The typical preformed niacin sources in diets are meat and meat products, cereals, dairy products, beverages, and eggs. However, cereals with esterified niacin in complexes have this vitamin imavail-able for absorption, but its bioavailability can be increased by treatment with alkali to hydrolyze the esters. Coffee can be a source of niacin, as nicotinic acid is liberated in coffee by roasting. 

PIXE with a proton microprobe has also been developed and has been applied to elemental distribution in plant and animal tissues, and human blood cells and tumors. Further, 3D micro-PIXE also has been developed to perform depth analysis recently and has a spatial resolution of 4 pm by using characteristic titanium K X rays (4.558 keV) produced by 3 MeV protons with beam spot size of 1 pm. ... 

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