Nicotinamide adenine dinucleotide. See

Dehydrogenases, which represent a majority of redox enzymes, are mostly NAD (Nicotinamide Adenine Dinucleotide, see Fig. 12.9) dependent. This cofactor is not directly bound to the enzyme but its presence in the medium is necessary because it acts as a carrier of two electrons and one proton, and it activates the biocatalytic function of the enzyme. 

See also NAD+, NADH NADP+, NADPH daily requirements 756, 769 Nicotinamide adenine dinucleotide. See NAD+, NADH... 

NAD acronym of Nicotinamide adenine dinucleotide (see). NAD represents the oxidized form, NADH the reduced form. 

Together with nuclear magnetic resonance spectroscopy studies indicating that the 3 -OH of ATP is esterified during the synthesis of arylazido- 8-alanine ATP, the above data indicate that the esterification of NAD by arylazido-yS-alanine occurs on the 3 -OH of the ribose associated with the adenine portion of the nicotinamide adenine dinucleotide (see Fig. 3). 

The sensors for lactate and penicilline in Table 8.5 make use of fluorescence itself rather than fluorescence quenching. The lactate sensors stand for a group of optodes where the inherent fluorescence of NAD (nicotinamide-adenine-dinucleotide, see Chap. 7, Sect. 7.4.2) is evaluated. Reaction (8.8) can be influenced by establishing a specific pH so that it runs either from left to right or right to left. In this way, lactate as well pyruvate sensors can be manufactured. 

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