BIOL 205 Chapter Notes - Chapter 5: Metabolic Pathway, Thermal Energy, Phagocytosis
7 Dec 2017
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Document Summary
Fluid mosaic: a description of membrane structure, depicting a cellular membrane as a mosaic of diverse protein molecules embedded in a fluid bilayer made of phospholipid molecules. Selective permeability: a property of biological membranes that allows some substances to cross more easily than others and blocks the passage of other substances altogether. Concentration gradient: an increase or decrease in the density of a chemical substance in an area. Cells often maintain concentration gradients of ions across their membranes. When a gradient exists, substances tend to move from where they are more concentrated to where they are less concentrated. Passive transport: the diffusion of a substance across a biological membrane, without any input of energy. Osmosis: the diffusion of water across a selectively permeable membrane. Tonicity: the ability of a solution surrounding a cell to cause that cell to gain or lose water.
