Chapter 12, Problem 1RTC

Summary Introduction

To write:

About the relationship of the Proton motive force with ATP and what produces this force. Also, explain the danger due to consumption of 2,4-dinitrophenol (DNP).

Introduction:

The proton motive force is a type of force that takes place when the cell membrane becomes energized. The reason for the cell membrane excitement is due to the electron transport reactions. The electron transport reactions are done by the electron carriers embedded in the membrane. Principally, this makes the cell to behave like a tiny battery. This energy of the cell could either be used in some work (locomotion of flagella) or be stored for later use in the form of ATP.

Explanation of Solution

Production of pmf and its relationship with ATP:

The Proton-motive force (pmf) is produced across the thylakoid membrane of chloroplasts and the mitochondrial inner membrane. This force is produced generally by a chemical (proton) and voltage gradient. Like the ATP molecules, the pmf is a type of stored energy. This stored energy in the pmf can be changed to ATP by the ATP synthase enzyme action.

The effect due to DNP:

Due to the intake of high doses of DNP, the protons get diffuse through the mitochondrial membrane. Proton diffusion will reduce the proton gradient through the inner mitochondrial membrane. Thus, it results in the pmf reduction. Therefore, the ATP formation from the ADP molecule, get a departure from the cell. The energy becomes very less for energy-dependent processes. Thus, DNP can be fatal at high doses.

Conclusion

Thus, the proton motive force is produced generally by a chemical (proton) and voltage gradient. Like the ATP molecules, the pmf is a type of stored energy. This stored energy in the pmf can be changed to ATP by the ATP synthase enzyme action. Due to the intake of high doses of DNP, the protons get diffuse through the mitochondrial membrane. Proton diffusion will reduce the proton gradient through the inner mitochondrial membrane. Thus, DNP can be fatal at high doses.