Aaron Esbenshade, Masters Thesis in fermentation and 3 years fermentation engineer at DuPont · Author has 660 answers and 470.6k answer views NAD+ and NADH are the cofactors that mediate catabolic processes, so NAD and NADH concentrations regulate catabolic pathways. read more
For glycolysis to continue, the cell needs a supply of oxidized NADH (ie NAD(+)) for the GAPdh reaction. So how do we regenerate the NAD(+). Well, take pyruvate and reduce it to lactate and regenerate NAD(+) from NADH (the LDH reaction). Glycolysis can now proceed and lactate is the 'waste' product. read more