Course Guide Chapter 6: Biological Membranes Flashcards
What are the components of the biological membrane?
phospholipids, integral/intrinsic proteins, peripheral/extrinsic proteins, cholesterol, carotenoids, glycolipids, and glycoproteins
How is the fluidity of the membrane affected by composition and temperature?
unsaturation increases membrane fluidity and lowers melting temperature
saturation reduces membrane fluidity and increases melting temperature
Define passive transport
does not need cellular energy and the transport happens from high to low concentrations (down the concentration gradient)
Define active transport
requires energy in the form of ATP, light or electrons. It transports against concentration gradient, from low to high concentrations
Define diffusion
the tendency of molecules and ions to spread out in the available space until they reach equilibrium due to their thermal motion
Define osmosis
the diffusion of water from high concentration to low concentration through a selectively permeable membrane
How does the solute concentration affect the water movement in an animal or plant cell?
Water moves from solutions with low solute concentration (high water concentration) to high solute concentration (low water concentration)
What is exocytosis?
vesicles from the ER or Golgi bodies carrying macromolecules and other materials to be secreted fuse with the plasma membrane and open outside to secrete the materials
What is phagocytosis?
macrophage engulfing bacteria identified for desctruction
What is pinocytosis?
refers to cells gulping droplets of extracellular fluid
What is receptor-mediated endocytosis?
specific receptor proteins recognize large molecules, change conformation and engulf low density lipoproteins containing several cholesterol molecules and related proteins into the cell for processing
