The Following Figure Illustrates a Proton Gradient

Multiple Choice

The following figure illustrates a proton gradient. In this figure, protons are indicated by small circles. Which part of the figure has the lowest pH?

A) part I because it has a lower concentration of protons
B) part II because it has a lower concentration of protons
C) part I because it has a higher concentration of protons
D) part II because it has a higher concentration of protons
E) They both have the same pH because pH has nothing to do with protons.