In: Biology
Radiolabeled NADH was added to cell extracts containing actively respiring mitochondria. After a short
incubation period, mitochondria were isolated by subcellular fractionation using density gradient
centrifugation and analyzed for radioactivity. In one experiment, tritium labelled NADH (3H-NADH) was used.
14C-NADH was used in a second experiment. Radioactivity was associated with mitochondria in only one of
these experiments. Which one? Explain.