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Unformatted text preview: Facilitated diffusion---substance to be transported combines with a plasma membrane carrier protein called a transporter. Transporters are specific to one substance. As the substance molecule moves into the open end of the transporter molecule, its presence causes the carrier molecule to change shape. The open end of the carrier in now on the inside of the cell, so the substance moves on in. The carrier releases the substance and returns to the original shape, ready to repeat the process. Movement can continue as long as the substance is moving from higher concentration to lower concentration. d) Passive processes are less important in bacterial cells than in eukaryotic cells. One reason is that bacterial cells frequently find themselves in surroundings where nutrients are in low concentration, so passive processes are unable to meet their needs. Another point is that only concentration, so passive processes are unable to meet their needs....
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This note was uploaded on 01/23/2012 for the course MCB MCB2010 taught by Professor Smith during the Fall '09 term at Broward College.
- Fall '09