Light-activated error-free DNA repair (4)

The results of the experiments suggested that only one hydrogen was actually involved in the rate-limiting step of H2 formation, and not two as the stoichiometry of the reaction indicates.

There is still work to be done to understand the mechanism of the other H2 evolution process that leads to N2 binding, activation, and reduction to NH3.

I do not believe that two different types of hydrogen evolved.SARCASM ALERT: But maybe that’s what I’m wrong about.But see: Promises and Challenges in Continuous Tracking Utilizing Amino Acids in Skin Secretions for Active Multi-Factor Biometric Authentication for Cybersecurity (with my emphasis)

Figure 1. Biocatalytic cascade for optical detection of three amino acids, using two detection pathways: A) measurement of NADH at 340 nm, and B) conversion of NADH to a visible color (formazan) via NBT/PMS which is observable at 580 nm.As shown in Figure 1, amino acids (glutamate, in this case) can be analyzed in two ways. Pathway A utilizes the UV properties of NADH alone, which can be observed[47] at 340 nm. Pathway B implements phenazine methosulfate (PMS) and Nitroblue tetrazolium (NBT). Here, PMS mediates the reaction of NADH reducing NBT to a colored product, formazan, which can be measured spectrophotometrically at 580 nm. Changing the starting enzyme and other chemicals as appropriate, the system can be adapted for the detection of alanine and phenylalanine using the same method. Alanine can be analyzed using an enzyme system containing alanine dehydrogenase (AlaDH; E. C. 1.4.1.1). AlaDH consumes alanine and NAD+ to produce pyruvate (Pyr), NH3nine and NAD+, and NADH. Phenylalanine dehydrogenase (PheDH; E. C. 1.4.1.20) produces phenylpyruvate (PhPyr), NH3, and NADH in the presence of phenylala. These two systems can be devised similarly to the glutamate cascade, with either pathway A, direct observation of NADH at 340 nm,[47] or pathway B, conversion of NADH to formazan via NBT/PMS which is observable at 580 nm.[48]