BI110 Lecture Notes - Lecture 15: Symporter, Active Transport, Aquaporin
Document Summary
Two compartments separated by a semipermeable membrane. Membrane is permeable to water but not to the solute (sugar) Equilibrium is reached when concentration is equal on both sides. Water molecules move across membrane to equalize concentration of both sides. At equilibrium, concentrations on both sides are the same even though liquid level is different. Opposite of diffusion as the water is moving. Water moves into or out of cells depending on the tonicity of the solutions. Has the same solute concentration as the intracellular fluid. Has a lower concentration of solute molecules compared to intracellular fluid. Has a higher concentration of solute molecules compared to intracellular fluid. Facilitated diffusion: passive transport of substances at rates higher than predicted from their lipid solubility. Depends on membrane proteins (unlike simple diffusion, which doesn"t need anything) Becomes saturated at high concentrations of transported substance. The rate of facilitated is faster at small concentrations than simple diffusion.
