So in the cytoplasm of our cells, the glucose is transformed into Pyruvate via glycolysis. And under certain circumstances, the Pyruvate can even be transformed back into glucose. Now, if we have plenty of oxygen in our cell and our cell wants to produce ATP molecules, the Pyruvate will enter the matrix of the mitochondria. And in the matrix, the Pyruvate will be transformed via an irreversible step into acetyl coenzyme A. And what this step does is it commits the CETL coenzyme A, the derivative of Pyruvate, into one of two different pathways. We either commit the CETL coenzyme A to undergo the TCA cycle, the citric acid cycle, or also known as trichrobicylic acid cycle to generate those NADH molecules and fadh two molecules to basically form ATP via the electron transport chain.