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Unformatted text preview: + plays a vital role in opening and closing of stomata (see later) . Plant cells also rely on active transport. The H + proton pump is a common use of active transport. The cell creates a proton gradient by pumping H + out of the cell, which is a source of potential energy (for the passive diffusion of the H+ back into the cell through the membrane), and creates the membrane potential (the differential charge between the interior, more negative charge, and external more positive charge), a second source of potential energy. Proton Gradient and Membrane Potential Membrane Potential favors diffusion of + ions The membrane potential facilitates the movement of positively charged ions into cells. The ion movement is “passive” but is a consequence of the active movement of H + through the proton pump that maintains the membrane potential. The proton pump moves many minerals into cells in quantities greater than what is found in the environment....
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This note was uploaded on 01/08/2012 for the course BIO 213 taught by Professor Makina during the Fall '09 term at SUNY Stony Brook.
- Fall '09