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.

Question

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.

Quizplus · Accepted Answer

Part II has a higher concentration of protons, which means it has a lower pH. pH is a measure of the concentration of hydrogen ions (protons) in a solution, so areas with higher proton concentrations will have lower pH values.

The Following Figure Illustrates a Proton Gradient