NAD+ vs. NADH

https://www.nad.com/nad-vs-nadh

NADH carries the electrons gained from the breakdown of glucose and donates them to the chain of enzymes in mitochondria that are involved in producing ATP (electron transport chain). This oxidizes NADH back to NAD+. Ultimately, the energy from the electrons donated by NADH is exploited by mitochondria to produce ATP (oxidative phosphorylation).

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figured it out, the + on the Nitrogen just means it already Methylated and capable of transporting Hydrogen & manufacturing NAD+ NADH Hydrogen transport into ATP.

the + is a little hand that grabs Hydrogen & drops it off.

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Nicotinamide N-methyltransferase: At the crossroads between cellular metabolism and epigenetic regulation

https://pmc.ncbi.nlm.nih.gov/articles/PMC7868988/

Source of nicotinamide governs its metabolic fate in cultured cells, mice, and humans

https://www.cell.com/cell-reports/fulltext/S2211-1247(23)00229-2