MBB 222 Study Guide - Final Guide: Relative Permittivity, Amphiphile, Protein Structure

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Water is a polar solvent and readily dissolves most biomolecules (which are generally charged or polar compounds) Hydrophilic = water loving" molecules that are polar and will dissolve easily in water. Chloroform and benzene are poor solvents for polar molecules) Hydrophobic = water hating" and will not dissolve easily in water. In contrast, nonpolar solvents will easily dissolve these molecules. Nonpolar molecules include things like lipids and waxes. Water is effective in screening (weakening) the electrostatic interactions between dissolved ions as it has a high dielectric constant. More screening (a higher dielectric constant) means more weakening of solute-solute ionic interactions. Ionic interactions form by the interaction of oppositely charged groups, forming an ion pair or salt bridge that can have either a stabilizing or destabilizing effect to the protein structure. Salt bridge strength increases as it moves to an environment with a lower dielectric constant. Salt bridges that are buried can provide significant stabilization to a protein structure.