BIOL 1201 Chapter : Chapter 7
Document Summary
>>>>>membrane structural models have evolved as new data is acquired. Indirect because we couldn"t see membranes, didn"t have good enough microscopic images. Biochemical detective work: membranes are made of lipid. Evidence: lipids and lipid soluble material enter quicker than substances which are insoluble in 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. Evidence: biological membranes absorb more water on their surface than artificial: biological membranes are coated with proteins that generally absorb water. phospholipid membranes. Davson-danieli model : two scientists put forth to explain all the above date.
