The mineral cofactors described above may be thought of as representing a special subset of the biominerals. Rather than contributing to skeletal mass and fluid homeostasis, however, mineral cofactors are subtler and are devoted specifically to enzymes. The words 'mineral' and 'cofactor' combine to designate an inorganic component required by an enzyme in order to achieve optimum catalytic efficiency. In seeking a reason for mineral confactors, one must consider that to meet its functional obligations, an enzyme faces many challenges. The protein surface can easily be modified chemically through interaction with substrates and the enzyme protein can readily lose its biological form through denaturation. Electrons and groups that are transferred to and from substrates have the potential to permanently modify the enzyme. This happens frequently and instead of undergoing repair, old enzymes are replaced by new ones. The mineral cofactors fit into the daily wear and tear by making the enzyme better able to stand up to the harsh environment of their existence. They also have been shown to be effective binders of substrate and to interact with oxi-dants and reductants in a facile manner. Some trace metals such as zinc can accept electron pairs in forming a covalent attachment that polarizes and facilitates rupture of the chemical bonds in the substrate. Other metals such as copper and iron can accept electrons from the substrate and pass them to oxygen. Catalysis and structure stability are the two primary functions of metals in enzymes. Many organic factors serve as electron-capturing and group-transferring agents (see 00059). This suggests that metalloen-zymes may back up enzymes with organic cofac-tors. This view is rather narrow and oversimplified since there are many enzyme-catalyzed reactions where only a metal will suffice, such as in the metalloenzymes that catalyze the destruction of oxygen radicals. In biology seldom does one factor become indispensable. What nutritionists refer to as essential metals are on the same level as vitamins in that they are needed in very small quantities to maintain the status quo in a system and, like vitamins, are available strictly through the diet. Therefore, one must conclude that essential minerals and vitamins have common ground in the enzymes, which they literally permit to function.

Dieting Dilemma and Skinny Solutions

Dieting Dilemma and Skinny Solutions

The captivating thing about diets is that you don't get what is researched or predicted or calculated but rather, you get precisely what you expect. If the diet resonates with you then it will likely work, if it doesn't resonate, it won't.

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