Nevner hvordan CO2 inngår direkte i Krebs syklus og NADH. Hele studien finnes som pdf i denne linken.

http://onlinelibrary.wiley.com/doi/10.1111/j.1432-1033.1976.tb11021.x/full

Proof for this reaction is supplied by the detection of a CO2-dependent NADH oxidation, and by the identification of [¹⁴C]carbonate.

That CO2 and not HCO3 is the active species in the reduction was shown by comparing the pH dependency of the velocities of the forward and back reactions and by observing the kinetics of CO2 reduction during the simultaneous attainment of the CO2-HCO−3 equilibrium.