Final answer:
Chemiosmosis in cellular respiration involves the movement of protons from the mitochondrial matrix to the intermembrane space by the electron transport chain and results in ATP production via ATP synthase.
Correct option is a) Protons; mitochondrial matrix to intermembrane space
Step-by-step explanation:
During the chemiosmosis phase of cellular respiration, protons (hydrogen ions, H+) are moved from the mitochondrial matrix to the intermembrane space. This occurs in the mitochondria, which is an organelle with an inner and outer membrane. The space between the inner and outer membranes is known as the intermembrane space, while the space enclosed by the inner membrane is the matrix.
The electron transport chain, which is part of the last stage of cellular respiration, facilitates this movement by pumping protons into the intermembrane space, creating an electrochemical gradient. Then, these protons flow back into the matrix through the ATP synthase enzyme, driving the production of ATP from ADP and inorganic phosphate.