NAD+ redox cofactor, laboratory definition

NAD+ is nicotinamide adenine dinucleotide, a redox cofactor in dehydrogenase reactions and a substrate in some DNA-repair and signaling reactions. It is not a peptide: it is not a chain of amino acids. It sits on the mitochondrial category route because energy-metabolism orders often place it beside mitochondrial peptides. That shelf is taxonomy.

The catalog fills are on NAD+. The note that separates the cofactor literature from consumer IV marketing is NAD+ in energy-metabolism research. A peptide Certificate of Analysis does not document this cofactor.