It functions as a molecular motor driven by the flow of protons, converting their energy into the synthesis of ATP from ADP and phosphate.

The text you provided describes the function of ATP synthase, an enzyme that plays a crucial role in cellular respiration. Here's a step-by-step explanation:

1. ATP synthase is located in the mitochondria, the powerhouses of the cell. It is embedded in the inner mitochondrial membrane.

2. Protons (H+ ions) are pumped from the mitochondrial matrix to the intermembrane space by other components of the electron transport chain. This creates a concentration gradient.

3. The protons then flow back into the matrix through ATP synthase due to this gradient. This flow of protons is also known as chemiosmosis.

4. The energy from this flow of protons is used by ATP synthase to convert ADP (adenosine diphosphate) and inorganic phosphate into ATP (adenosine triphosphate).

5. ATP, the main energy currency of the cell, is then used to power various cellular processes.

In summary, ATP synthase acts as a molecular motor, using the energy from the flow of protons to synthesize ATP from ADP and phosphate.