Campbell biology chapter 7 12th Edition Exam Q’S AND A’S

Campbell biology chapter 7 12th Edition Exam Q’S AND A’S plasma membrane - answer- - in every cell - separate cell from surroundings - selectively permeable - all cell membranes vary in chemical composition - adapt membrane through enviornment transport proteins - answer- responsible for controlling passage across cellular membranes Amphipathic molecules - answer- has both hydrophobic and hydrophilic reigons phosphate group - answer- hydrophilic fatty acids - answer- hydrophobic Fluid mosaic model - answer- individual units that make up a membrane; has some movement cholesterol - answer- used to keep fatty acids in line peripheral proteins - answer- on surface of membrane, don't go through membrane (external or internal) integral proteins - answer- go through membrane; will go into hydrophobic region (lipids) must be chemically different - hydrophobic reigon has stretches of nonpolar amino acids in a alpha helix transmembrane proteins - answer- type of integral protein that goes through the entire membrane functions of cell-surface membrane proteins - answer- -transport -location of Enzyme activity -signal transduction -cell-cell recognition -intercellular joining -attach to cytoskeleton and ECM cell-cell recognition - answer- cells contain glycoproteins or sugars for other cells to identify it on plasma membrane signal transduction - answer- The process by which a cell responds to substances outside the cell through signaling molecules found on the surface of and inside the cell glycolipids - answer- membrane carbohydrates covalently bonded to lipids What passes through membranes easily - answer- Hydrophobic lipids/ nonpolar molecules What needs a protein to pass through membranes - answer- Hydrophilic molecules including ions and polar molecules types of transport proteins - answer- carrier proteins and channel proteins Carrier proteins - answer- the substance will bind to carrier protein, then change shape as modified form channel proteins - answer- they have an opening straight through to the cell aquaporins - answer- channel proteins that will transport water passive transport - answer- does not require ATP/ energy to transport substance across membrane (from high concentration to low concentration) active transport - answer- requires ATP/ energy to transport substance across membrane (from low concentration to high concentration) types of passive transport - answer- - Diffusion (simple) - Facilitated Diffusion - Equilibrium - Osmosis Concentration Gradient - answer- occurs when the concentration of particles is higher in one area than another Diffusion (simple) - answer- - Goes right across the membrane - passive transport - moves along concentration gradient Take a sugar cube and put into coffee Facilitated Diffusion - answer- requires use of transport proteins; needs help - passive transport Osmosis - answer- looking at concentration and movement of water Tonicity - answer- the concentration of the solutes Types of Osmosis - answer- - refers to concentration of solute outside the