The combined chemical and electrical gradient of protons that powers ATP synthase and transport.
PMF = Δψ (membrane potential) + ΔpH term. In mitochondria, it is dominated by membrane potential (about -180 mV). It also drives transport (phosphate, ADP/ATP exchange) and bacterial flagella.
PMF has two parts; in chloroplasts the ΔpH dominates. It also drives ADP/ATP exchange.
Key idea: PMF is a store of energy used for several cell processes.
The combined chemical and electrical gradient of protons that powers ATP synthase and transport.
Proton Motive Force is one of the 53 topics in Metabolism & Bioenergetics. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Chemiosmosis, ATP Synthase Rotary Mechanism, Mitochondrial Uncoupling.
Bacteria use PMF to spin flagellar motors.
Work through the Beginner topics in Metabolism & Bioenergetics first, such as Metabolism, Anabolism and Catabolism, ATP, then return to Proton Motive Force. Advanced topics assume the Intermediate vocabulary.
The closest topics to Proton Motive Force are Chemiosmosis, ATP Synthase Rotary Mechanism, Mitochondrial Uncoupling, Oxidative Phosphorylation. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Proton Motive Force. To practise the whole of Metabolism & Bioenergetics, use the Metabolism & Bioenergetics quiz.
Proton Motive Force: The combined chemical and electrical gradient of protons that powers ATP synthase and transport. Chemiosmosis: Protons flowing back through ATP synthase down their gradient drive the formation of ATP. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Chemiosmosis and explain the difference aloud. Finally, take the Metabolism & Bioenergetics quiz and come back to this page for any question you miss.
Protons flowing back through ATP synthase down their gradient drive the formation of ATP.
⚡ Metabolism & BioenergeticsProton flow turns the F0 rotor, driving conformational changes in F1 that make ATP, like a molecular turbine.
⚡ Metabolism & BioenergeticsUncoupling proteins dissipate the proton gradient as heat, as in brown adipose tissue.
⚡ Metabolism & BioenergeticsATP synthesis driven by electron transport and the proton gradient across the inner membrane.
⚡ Metabolism & Bioenergetics