In a eukaryotic cell, glycolysis and the citric acid cycle are linked by the transport of which molecule to which location?

• A. Cytosol
• B. Mitochondrial Matrix
• C. Nucleus
• D. Golgi apparatus

Answer: (B)

Glycolysis happens in the cytosol and yields pyruvate, which must move into the mitochondrion to feed the citric acid cycle. The citric acid cycle runs in the mitochondrial matrix, so pyruvate is transported into that space where it is converted to acetyl-CoA by the pyruvate dehydrogenase complex, producing NADH and CO2 in the process. This transfer to the mitochondrial matrix is what links glycolysis to the citric acid cycle, making the mitochondrial matrix the correct destination. The other cellular locations listed aren’t where the citric acid cycle operates or where glycolysis products are used to feed it.