LEHNINGER PRINCIPLES OF BIOCHEMISTRY CHAPTER 11 QUESTIONS WITH CORRECT ANSWERS

Micelles CORRECT ANSWER Spherical structures that contain anywhere from a few dozen to a few thousand amphipathic molecules. The non polar portions in the interior and the polar portions at the exterior surface, exposed to water Fluid Mosaic Model CORRECT ANSWER The concept that cell membranes are lipid bilayer structures that contain an assortment of polar lipids and proteins in a dynamic fluid arrangement Bilayer CORRECT ANSWER A second type of lipid aggregate in water, in which 2 lipid monolayers (leaflets) form a 2-dimensional sheet. Vesicle CORRECT ANSWER Is the result of a 2-dimensional bilayer folding on itself to form a closed bilayer, a 3-dimensional hollow vesicle (liposome) enclosing an aqueous cavity. Integral membrane proteins CORRECT ANSWER Firmly associated with the lipid bilayer and are removable only by agents that interfere with hydrophobic interactions, such as detergents, organic solvents, or denaturants. Peripheral membrane proteins CORRECT ANSWER Associate with the membrane through electrostatic interactions and hydrogen bonding with the hydrophilic domains of integral proteins and with the polar head groups of lipids. They can be released by relatively mild treatments that interfere with electrostatic interactions or break hydrogen bonds; a commonly used agent is carbonate at high pH.