02-20-2007, 09:41 AM
If a ketoglutarate/oxaloacetate shuttle was present, could a new shuttle be formed that would replace the malate-aspartate shuttle by eliminating the transamination reactions and the amino acid translocase?
A. Yes. Ketoglutarate/oxaloacetate could substitute for glutamate/aspartate.
B. No. This shuttle would not work, because there would be a net flow of protons into the mitochondria during the entry/exit of both ketoglutarate and oxaloacetate.
C. No. This shuttle would not work, because there would be a net charge change during the antiport of ketoglutarate/oxaloacetate.
D. No. This shuttle would not work, because oxaloacetate in the mitochondria would be immediately consumed in the citric-acid cycle.
A. Yes. Ketoglutarate/oxaloacetate could substitute for glutamate/aspartate.
B. No. This shuttle would not work, because there would be a net flow of protons into the mitochondria during the entry/exit of both ketoglutarate and oxaloacetate.
C. No. This shuttle would not work, because there would be a net charge change during the antiport of ketoglutarate/oxaloacetate.
D. No. This shuttle would not work, because oxaloacetate in the mitochondria would be immediately consumed in the citric-acid cycle.