FREE BOOKS

Author's List




PREV.   NEXT  
|<   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   >>  
nclude the alcohol, to which the fatty acids and choline phosphate are attached, for example, glycerol can be replaced by the so-called meat-sugar, inositol, which has six hydroxyl groups in its hexagon-shaped molecule C_{6}H_{6}(OH)_{6}. [Illustration: Figure 14.--EDUARD BUCHNER (1860-1917) received the Nobel Prize in Chemistry for his discovery of cell-free fermentation, the first step in finding the role of phosphate in fermentations (1907).] The generally similar behavior of these phosphate-and fat-containing substances was emphasized by Ludwig Thudichum (1829-1901). He coined the name phosphatides for this group of substances from seeds and nerves.[29] His work on the phosphates in brain substance aroused particular interest. When William Crookes drew his highly imaginative picture of an "evolution" of the chemical elements, he put into it "phosphorus for the brain, salt for the sea, clay for the solid earth...."[30] But phosphatides occur in many places of organisms, in bacteria, in leaves and roots of plants, in fat and tissues of animals. And where phosphatides are found, there are also enzymes that specifically act on them. They are called phosphatases to imply that they split the phosphatides. In addition, enzymes are present, which transfer phosphate groups from one compound to another. They are more abundant in seeds of high fat content than in the more starch-containing seeds, but even potatoes and orange juice have phosphatases.[31] Thus, from phosphatides, phosphoric acid is generated, and they could also be called phosphagens. Since 1926, however, the name phosphagens has been reserved for a group of organic substances that release their phosphoric acid very readily. The link between phosphorus and carbon is provided by oxygen in the phosphatides, by nitrogen in the phosphagens. In vertebrates, the basis for the phosphoric acid is creatine, whereas invertebrates have arginine instead. H OH OH | / / N--P=O NH--P=O / \ / \ C=NH OH C=NH OH \ \ N--CH_{2}COOH NH | | CH_{3} CH_{2} | Creatine phosphate CH_{2} | CH_{2} | CHNH_{2} |
PREV.   NEXT  
|<   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   >>  



Top keywords:

phosphatides

 

phosphate

 
substances
 

phosphoric

 

phosphagens

 

called

 

phosphatases

 

enzymes

 

phosphorus

 
groups

bacteria
 

transfer

 

leaves

 
present
 
organisms
 

compound

 

places

 
Creatine
 

addition

 
specifically

tissues

 
animals
 
plants
 

readily

 

release

 

reserved

 
organic
 

carbon

 

invertebrates

 
creatine

vertebrates
 

nitrogen

 

arginine

 

provided

 

oxygen

 

potatoes

 

starch

 

content

 

orange

 
generated

abundant
 
picture
 

received

 

BUCHNER

 

Figure

 
EDUARD
 

Chemistry

 

discovery

 

finding

 

fermentations