BIOL 1201 Chapter : Biol 1201 Outline7
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>>>>>membrane structural models have evolved as new data is acquired. Biochemical detective work: membranes are made of lipid, phospholipids are amphipathic molecules that can form membranes. --amphipathic a condition where a single molecule has both hydrophilic and hydrophobic regions: cell membranes are phospholipid bilayers (see fig 7. 2) Evidence: the phospholipid content of red blood cells is just enough to cover the cell with two layers. The red blood cell has no internal membranes: biological membranes contain proteins. Evidence: membranes isolated from red blood cells contain proteins in addition to lipids: biological membranes are coated with proteins that generally absorb water. Evidence: biological membranes absorb more water on their surface than artificial phospholipid membranes. Hydrophilic zones = polar head groups + globular proteins. Hydrophilic zones = polar head groups + hydrophilic portion of proteins. Hydrophobic zone = 2 x hydrophobic tails + hydrophobic portion of. Singer and nicolson: fluid-mosaic model (see fig 7. 3)
