Question

The proton motive force is key to ________ because the H+ electrochemical gradient is _________ in the intermembrane space than inside the matrix?

Answer 1

The proton motive force is essential for chemiosmosis, playing a critical role in oxidative phosphorylation by creating a higher H+ gradient in the intermembrane space which drives ATP synthesis.

Step-by-step explanation:

The proton motive force (PMF) is key to chemiosmosis because the H+ electrochemical gradient is higher in the intermembrane space than inside the matrix. This gradient is a crucial component in the process of oxidative phosphorylation, where it drives the synthesis of ATP, the energy currency of the cell. As electrons move through the electron transport chain (ETC), protons are pumped across the mitochondrial membrane, creating a higher concentration of hydrogen ions in the intermembrane space compared to the matrix. This establishes both concentration and electrical gradients, which are utilized by ATP synthase to generate ATP when H+ ions flow back into the matrix.