Comparing chemiosmosis in cell respiration & photosynthesis
The generation of a proton gradient across a membrane and chemiosmosis are universal to life on earth, and are fundamental ways for cells to make a living. Lane and colleagues speculate that “proton power” may have been the earliest form of energy metabolism, essential to, and pre-dating, the last universal common ancestor, LUCA (Lane, 2009; Lane et al. 2010).
Similarities and differences between chemiosmosis …
In addition to ATP synthesis, prokaryotic cells can use the proton motive force to supply energy for active transport of molecules across the plasma membrane, and to power the motor complex that rotates the bacterial .
The membrane electron transport chain and chemiosmosis is a strategy for cells to maximize the amount of ATP they can make from the large amounts of free energy available in NADH. The electron transport chain subdivides the oxidation of NADH by O2 to a series of lower energy redox reactions, which are used to pump protons across the membrane. The resulting H+ concentration (pH) gradient across the membrane is a form of stored energy, analogous to an electric battery.
chemiosmosis - Innovative-Teaching
According to the chemiosmosis theory, as the electrons are transported down the electron transport chain, some of the energy released is used to pump protons across the thylakoid membrane from the stroma of the chloroplast to the thylakoid interior space producing a proton gradient or proton motive force.
Respiration, chemiosmosis and oxidative phosphorylation
As the accumulating protons in the thylakoid interior space pass back across the thylakoid membrane to the stroma through ATP synthetase complexes, this proton motive force is used to generate ATP from ADP and P.