The covalent bonds that unite the phosphate units in ATP are high

The covalent bonds that unite the phosphate units in ATP are high

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The covalent bonds that unite the phosphate units in ATP are high-energy bonds. When an ATP  molecule is broken down by an enzyme, the third (terminal) phosphate unit is released as a  phosphate group, which is a phosphate ion (Figure  1  ). With the release, approximately 7.3  kilocalories of energy (a kilocalorie is 1000 calories) are made available to do the work of the  microorganism.  The breakdown of an ATP molecule is accomplished by an enzyme called adenosine  triphosphatase. The products of ATP breakdown are adenosine diphosphate (ADP) and, as noted, a  phosphate ion. Adenosine diphosphate and the phosphate ion can be reconstituted to form ATP,  much as a battery can be recharged. To accomplish this ATP formation, energy necessary for the  synthesis can be made available in the microorganism through two extremely important processes:  photosynthesis and cellular respiration. A process called fermentation may also be involved. 
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Unformatted text preview: ATP production. ATP is generated from ADP and phosphate ions by a complex set of processes occurring in the cell, processes that depend upon the activities of a special group of cofactors called coenzymes. Three important coenzymes are nicotinamide adenine di-nucleotide (NAD), nicotinamide adenine dinucleotide phosphate (NADP), and flavin adenine dinucleotide (FAD). All are structurally similar to ATP. All coenzymes perform essentially the same work. During the chemical reactions of metabolism, coenzymes accept electrons and pass them on to other coenzymes or other molecules. The removal of electrons or protons from a coenzyme is called oxidation. The addition of electrons or protons to a coenzyme is called reduction. Therefore, the chemical reactions performed by coenzymes are called oxidation-reduction reactions....
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This note was uploaded on 11/11/2011 for the course BIO 101 taught by Professor Pesthy during the Fall '07 term at Texas State.

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