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Unformatted text preview: Movement of Substances There are a few concepts that need to be understood relating to the movement of substances. • The movement of substances may occur across a semi-permeable membrane (such as the plasma membrane). A semi-permeable membrane allows some substances to pass through, but not others. • The substances, whose movements are being described, may be water (the solvent) or the substance dissolved in the water (the solute). • Movement of substances may occur from higher to lower concentrations (down the concentration gradient) or from the opposite direction (up or against the gradient). • Solute concentrations vary. A solution may be hypertonic (a higher concentration of solutes), hypotonic (a lower concentration of solutes), or isotonic (an equal concentration of solutes) compared to another region. • The movement of substances may be passive or active. If movement is with the concentration or • The movement of substances may be passive or active....
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- Spring '10
- concentration gradient, energy consumption, substances, SemiPermeable Membrane