BIOL 1001 Chapter : Biology Chapter 5 Lecture Notes
Document Summary
5. 1 how is the structure of a membrane related to its function: cell membranes isolate cell contents while allowing communication with the environment. It isolates the cell"s contents from the external environment. Phospholipids are responsible for the isolating function of membranes. Proteins are responsible for selectively exchanging substances and communicating with the environment, controlling biochemical reactions, and forming attachments: membranes are fluid mosaics in which proteins move within layers of lipids. The fluid mosaic model of a membrane was proposed in 1972 by s. j. Phospholipids are the basis of membrane structure and consist of two very different parts: a polar, hydrophilic head, two nonpolar, hydrophobic tails. Plasma membranes face both exterior and interior watery environments. The phospholipid bilayer"s flexible, fluid membrane allows for cellular shape. Individual phospholipid molecules are not bonded to one another. Some of the phospholipids have unsaturated fatty acids, whose double bonds introduce kinks into their tails . The above features make the membrane fluid.
