The Cell Can Change the PH of Its Internal Compartments

The cell can change the pH of its internal compartments using membrane transport proteins that pump protons into or out of a compartment. How many protons should be pumped into an endocytic vesicle that is 10-¹⁵ liters in volume and has a neutral pH in order to change the pH to 5? Avogadro's number is 6 × 10²³. Omit complications such as the membrane potential, buffers, and other cellular components.

A) 6000
B) 60,000
C) 120,000
D) 600,000
E) 6,000,000