Membranes160-page11 - one to release ATP to provide the...

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Membrane Structure and Function - 11 Energy-Requiring Transport Across Membranes All cells need to move some substances through membrane in a direction counter to the gradient, or move substances that are too large or bulky be moved without the use of cell energy. Cells have a number of ways to move things with the use of energy. Active Transport Some transport proteins (carrier proteins) can move substances through the membrane against the concentration gradient. Active transport typically requires two carrier protein active sites: one to recognize the substance to be carried, and
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Unformatted text preview: one to release ATP to provide the energy for the protein carriers or "pumps". Much energy is expended by the cell to do this! In other cases, concentration gradients of ions, typically H + or Na + ions, can be used to provide the energy needed to move something through a membrane. For example, the substance to be moved is "coupled" to the concentration of H + , and while to H + is moving "down" through the carrier channel, the substance is transported "up". Active Transport...
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This note was uploaded on 12/29/2011 for the course BIO 151 taught by Professor Edwards during the Spring '10 term at SUNY Stony Brook.

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