ATP Synthase

The energy stored in the hydrogen ion gradient can be used to drive the synthesis of ATP from ADP and inorganic phosphate. The conversion is accomplished by a marvelous nanoma-chine called ATP synthase. At its most basic, the operation is a simple one and is summarized in Figure 12.9. Once again, the circle symbolizes the linkage between the enzyme and carrier functions. ATP synthase is a protein complex that is also known as mitochondrial ATPase because it can carry out the reverse reaction,...

Adpatp Exchanger

ATP synthase makes ATP inside the mitochondrion. For the ATP to be available to the rest of the cell, there needs to be a mechanism to enable it to leave the mitochondrion for use in the cytosol. This job is performed by another carrier, the ADP ATP exchanger. This protein has no enzymatic action it simply moves ADP in one direction across the mitochondrial inner membrane and ATP in the opposite direction. In most eukaryotic cells the carrier operates in the direction shown in Figure 12.3....