Image talk:Secundary active transport.svg
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I think this picture (which looks very nice, bravo) is misleading. In secondary active transport, a membrane receptor binds an ion and a solute. The ion is moved down its concentration gradient, and the energy provided by this downhill electrochemical gradient, allows the solute to move uphill against its electrochemical gradient.
This picture, however, does not show this. It shows the correct mechanics of the membrane protein, however the solute which is to be actively transported (the amino acid) looks as if it is moving down its electrochemical gradient (from high concentration to low concentration) rather than uphill with respect to its electrochemical gradient (from low concentration to high concentration). In fact, active transport is defined as the uphill movement of a solute by some means (either by using metabolic energy from ATP Hydrolysis, or by using the energy from the downhill motion of a secondary solute).
This information is found in any physiology or biochemistry textbook. I will cite Vander:
Vander, Sherman, Luciano (2001), "Human Physiology: The Mechanisms of Body Function, 8th Edition" McGraw Hill, New York, pp.126-127, and figure 6-14
Vihsadas 07:39, 17 March 2007 (UTC)
