What is the relationship between the proton motive force and ATP?
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.
How is the proton motive force established?
The proton motive force occurs when the cell membrane becomes energized due to electron transport reactions by the electron carriers embedded in it. Trapping the ions on either side of the membrane creates two things, which together make the proton motive force: a pH and a charge difference.
What happens if there is no proton gradient?
In metabolic control, the inner mitochondrial membrane must remain impermeable to protons. When this occurs, the electron transport won’t run unless oxidative phosphorylation is occurring and oxidative phosphorylation won’t occur unless there is a proton gradient.
What is the importance of proton motive force?
How is proton gradient created?
The proton gradient generated by proton pumping during the electron transport chain is a stored form of energy. When protons flow through ATP synthase, they cause it to turn (much as water turns a water wheel), and its motion catalyzes the conversion of ADP and Pi to ATP.
Where does the proton gradient form?
A proton gradient is formed by two quinol (4H+4eā) oxidations at the Qo site to form one quinol (2H+2eā) at the Qi site (in total six protons are translocated: two protons reduce quinone to quinol and four protons are released from two ubiquinol molecules).
How is the proton gradient maintained?
At various stages in this process, protons are released into the thylakoid lumen or taken up from the stroma, generating a proton gradient. Such a gradient can be maintained because the thylakoid membrane is essentially impermeable to protons. The thylakoid space becomes markedly acidic, with the pH approaching 4.
What is the meaning of electrochemical proton gradient?
The electrochemical proton gradient is a difference hydrogen ion concentration across a membrane producing a concentration gradient and an electrical potential gradient. The gradient created by this allows hydrogen back across the membrane, through an enzyme called ATP synthase.
What is a proton gradient explain why this is important for the production of ATP?
When enough protons have accumulated, the proton motive force powers the formation of ATP. So a gradient allows cells to save up protons as “loose change”, and that makes all the difference in the world ā the difference between growth and no growth, life and no life.
What is the concentration gradient?
A concentration gradient occurs when the concentration of particles is higher in one area than another. In passive transport, particles will diffuse down a concentration gradient, from areas of higher concentration to areas of lower concentration, until they are evenly spaced.
What is the purpose of the proton gradient in the mitochondria?
The electrochemical proton gradient across the inner mitochondrial membrane is used to drive ATP synthesis in the critical process of oxidative phosphorylation (Figure 14-14). This is made possible by the membrane-bound enzyme ATP synthase, mentioned previously.
What is the function of the proton gradient in the mitochondrion quizlet?
What is the function of the proton gradient in the mitochondrion? It is potential energy that can power ATP synthesis.
What maintains the proton gradient in the mitochondria in the absence of o2?
Oxygen also binds with free protons in the matrix to form water ā removing matrix protons maintains the hydrogen gradient. In the absence of oxygen, hydrogen carriers cannot transfer energised electrons to the chain and ATP production is halted.
What is active transport give example?
Active transport is usually associated with accumulating high concentrations of molecules that the cell needs, such as ions, glucose and amino acids. Examples of active transport include the uptake of glucose in the intestines in humans and the uptake of mineral ions into root hair cells of plants.