FMN, FAD, NAD, NADP - What are they? скачать в хорошем качестве

FMN, FAD, NAD, NADP - What are they?

In NADH, the oxidoreduction involves the nicotinamide ring. In FADH2, the oxidoreduction involves the isoalloxazine ring. Some More lines from Harper: NAD/NADP: Nicotinamide coenzymes consist of a nicotinamide ring linked to an adenosine via a ribose and a phosphate group, forming a dinucleotide. NAD+/ NADH are shown, but NADP+/NADPH are identical except that they have a phosphate group esterified to the 2′OH of the adenosine. An oxidation reaction involves the transfer of two electrons and one H+ from the substrate to the nicotinamide ring of NAD+ forming NADH and the oxidized product. The remaining hydrogen of the hydrogen pair removed from the substrate remains free as a hydrogen ion. NADH is oxidized to NAD+ by the reverse reaction. FAD: In oxidation reactions, the flavin (eg, FAD) accepts 2 electrons and 2 H+ in 2 steps, forming the semiquinone intermediate followed by the reduced flavin (eg, FADH2) and the substrate is oxidized. In the reverse (reduction) reaction, the reduced flavin gives up 2 electrons and 2 H+ so that it becomes oxidized (eg, to FAD) and the substrate is reduced.