nad molecule

nad molecule molecular chemical structural formula model nicotinamide adenine dinucleotide coenzyme metabolism nad plus redox reactions cellular respiration energy atp synthesis glycolysis krebs cycle oxidative phosphorylation nadh conversion sirtuins aging dna repair mitochondrial function precursors supplement riboside mononucleotide metabolic health immune cell signaling stress neuroprotection biosynthesis scientific diagram healthy health medical science biology exam knowledge lesson explainer education biochemistry quiz learning training teaching vector diagram