How does temperature affect the cell membrane?
Denaturation and Phase Changes
The cell-membrane is often depicted as a fluid mosaic model made up of a phospholipid bilayer with embedded protiens.
Phospholipids belong to a class of organic compounds called lipids (which also contains waxes, oils, and fats). As what you can observe from animal fats like butter, when heated they turn to liquid form. The same is true for phospholipids. Upon heating, they become more "runny" and fluid than normal, destroying their semi-permeability and even allowing the entrance of normally restricted substances. When chilled, the phospholipids become more rigid, restricting cell movement and even stopping the transfer of materials through the cell membrane.
Proteins are a bit more complex, but in simpler terms, they get "destroyed" or denatured from temperature fluctuations. Denaturation happens when a protein loses its original secondary, tertiary, or quaternary structure. In simpler terms, by destroying a protein's structure, you also destroy its efficiency and function. This is detrimental to the cell membrane, as its embedded proteins not only function as support but also as carriers of cell materials. Denaturation of proteins often happens due to pH and temperature changes.
For more information, you can visit http://www.ehow.com/about_5516866_effect-temperature-cell-membranes.html
Hope this helps.