Why does an electrochemical potential build up in mitochondria, but not in chloroplasts?
A)Proton movement into the thylakoid lumen is neutralized by the movement of other ions.
B)Proton movement into the intercristal space is neutralized by the movement of other ions.
C)Proton movement into the cristae lumen is neutralized by the movement of other ions.
D)The protons in chloroplasts are immediately joined to electrons.
E)The protons in mitochondria are immediately joined to electrons.

Question

Quizplus · Accepted Answer

In chloroplasts, protons are pumped into the thylakoid lumen during photosynthesis, but this movement is neutralized by the movement of other ions, such as Cl- or HCO3-. Therefore, no electrochemical potential is generated. In mitochondria, protons are pumped into the intermembrane space during respiration, and this creates an electrochemical potential that is used to power ATP synthesis.

Why Does an Electrochemical Potential Build Up in Mitochondria, but Not