BI110 Chapter Notes - Chapter Module 18: Hydrostatics, Systematic Chaos, Water Potential
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A: it is a barrier separating the cell from the outside, and a gatekeeper of incoming and outgoing materials (balance its inputs and outputs of energy and waste). If the molecule binds to a receptor the cell can respond and using the membrane will either repel, or transport it across the membrane. A: movement of materials from areas of generally higher concentrations to areas of generally lower concentrations (down the concentration gradient); requires no input of energy (because molecules and ions are in constant motion anyways). The bigger the gradient the faster diffusion rate. A: a difference in the concentration of a substance between two different areas, such as the two sides of a selectively permeable membrane. A: temperature: as temperature rises, molecules diffuse more rapidly. Size: smaller molecules diffuse faster than larger molecules. A: a mode of membrane transport in which substances diffuse across the membrane without the need for an energy input into the system.
