PLN 103 Lecture Notes - Lecture 3: Semipermeable Membrane, Hydrostatics, Osmotic Pressure
17 Nov 2015
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Document Summary
Proteoglycans, glycoproteins, and glycolipids: extend outside cell membrane, and form sticky sugar coat (glycocalyx) Functions of the glycocalyx: lubrication and protection, anchoring and locomotion, specificity in binding (receptors), recognition (immune response) Vesicular: where the cell will engulf a solute or bacteria it can happen through kinocytosis which creates a pit which engulfs the solute and pull it into the cytoplasm. Diffusion across a semipermeable membrane is going to move down a concentration gradient, it goes from a high concentration to a low concentration, it"s the movement of solutes. Simple diffusion: lipid soluble compounds including alcohol, fatty acids and steroids can cross the plasma membrane relatively easy. Channel-mediated diffusion: channels for components that are water soluble, allows for movement across the semi-permeable membrane; factors that influence it include size, charge and leak channels. Osmosis is the diffusion of water across the cell membrane. Moves from a high concentration of water to a low concentration of water across the membrane.
