Cell Membrane and Membrane Transport (U3) PDF

Cell Membrane and Membrane Transport (Ch 7) Characteristics of the plasma boundary of all cells membrane Determines the movement of substances in and out of the cell Model for membrane Fluid mosaic...

Cell Membrane and Membrane Transport (Ch 7) Characteristics of the plasma boundary of all cells membrane Determines the movement of substances in and out of the cell Model for membrane Fluid mosaic structure - membrane is fluid (more like olive oil than butter) - mosaic bc there are many different types of molecules mixed with phospholipids Cholesterol in membrane helps to maintain fluidity Mosaic characteristics of Glycolipids – plasma membrane phospholipids with sugar molecules attached Membrane proteins Transmembrane/integral Pass through membrane membrane proteins sticks out on both sides of membrane Peripheral Attached to the membrane on intracellular side Proteins with sugar attached Glycoproteins  Membrane Permeability Substances that pass Small nonpolar molecules freely across the plasma Ex. CO2 and O2 membrane Substances that cannot pass Polar and charged molecules freely - Cannot move through hydrophobic interior of membrane Large molecules PLASMA MEMBRANE IS SEMIPERMEABLE (OR SELECTIVELY PERMEABLE) Membrane allows some molecules to pass through