What is a proton motive force?
Energy that is generated by the transfer of protons or electrons across an energy-transducing membrane and that can be used for chemical, osmotic, or mechanical work.
What is proton motive force in cellular respiration?
A proton-motive force, in the form of a large proton concentration difference across the membrane, provides the energy for the membrane-localized ATP synthase (a molecular machine) to make ATP from ADP and inorganic phosphate (Pi).
How does the proton motive force work in bacteria?
In bacteria, the extrusion of protons by the electron transport chain results in an electrochemical gradient of protons, known as the proton motive force (PMF), generated across the cell membrane.
What builds a proton motive force?
In most cases the proton-motive force is generated by an electron transport chain which acts as a proton pump, using the Gibbs free energy of redox reactions to pump protons (hydrogen ions) out across the membrane, separating the charge across the membrane.
What are the two components of the proton motive force?
The protonmotive force across the inner mitochondrial membrane (Δp) has two components: membrane potential (ΔΨ) and the gradient of proton concentration (ΔpH).
How is proton motive force implicated during ATP generation?
Electron transport is coupled to ATP production at the ATP synthase via the pmf. As protons flow down the electrochemical gradient into the matrix through a channel in the ATP synthase Fo domain, a rotation of the ATP synthase F1 domain drives the phosphorylation of ADP to ATP.
How is the proton motive force converted into ATP?
When protons flow through a channel in the enzyme, the movement spins the protein, much like wind drives a turbine. The mechanical movement of this rotor provides the energy to add an inorganic phosphate group to adenosine diphosphate (ADP) to form ATP.
What are the two components of proton motive force explain how these components arise?
The pmf across the mitochondrial inner membrane (IM) manifests as a charge gradient (Δψm) and a chemical gradient (ΔpH). The two components of the pmf are linked in that protons are positively charged, giving rise to the Δψm component, and chemical separation across the IM gives rise to the ΔpH component.
Does fermentation use proton motive force?
During fermentation FOF1 hydrolyzes ATP, coupling proton transport to proton-motive force (pmf) generation. Despite that, pmf generated by ATP hydrolysis does not satisfy the energy budget of a fermenting cell.
How is the proton motive force PMF generated?
The classical view of oxidative phosphorylation is that a proton motive force (PMF) generated by the respiratory chain complexes fuels ATP synthesis via ATP synthase.
How is the proton motive force coupled with electron transport?
In an electron transport system, energy from electron transfer during oxidation-reduction reactions enables certain carriers to transport protons (H+) across a membrane. As the H+ concentration increases on one side of the membrane, an electrochemical gradient called proton motive force develops.
How does proton motive force help in ATP generation?
The proton-motive force created by the pumping out of protons by the respiratory chain complexes is in the mitochondria of most tissues mainly used to translocate protons through the ATP synthase complex, leading to the formation of ATP from adenosine diphosphate (ADP) and phosphate.