Cell Compartmentalization Practice Test

In mitochondria, the inner membrane separates the intermembrane space from the matrix. During cellular respiration, protons accumulate in the intermembrane space, creating a higher proton concentration than in the matrix. When a chemical uncoupler makes the inner membrane permeable to protons, oxygen consumption continues but ATP production drops. Which feature best explains how this compartmentalization normally supports ATP synthesis?

In a eukaryotic cell, enzymes that break down fatty acids are located inside a peroxisome, while many cytosolic proteins are outside it. The peroxisome membrane restricts diffusion of these enzymes and concentrates fatty acid substrates inside the organelle. When the peroxisome membrane is experimentally made leaky, fatty acid breakdown rate decreases even though total enzyme amount is unchanged. Which feature best explains how compartmentalization increased the original reaction efficiency?