Cell Membrane Transport and Osmosis - Prof. Douglas N. Ishii, Study notes of Biology

Download Cell Membrane Transport and Osmosis - Prof. Douglas N. Ishii and more Study notes Biology in PDF only on Docsity! 20 January Na+ concentration higher outside the cell Ca2+ Cl- HCO3 - Glucose K+ concentration higher inside the cell Mg2+ Pi Amino acids ATP Protein Four Primary Transporters Na+/K+ ATPase 3 Na+ out 2 K+ in H+/K+ ATPase 1 H+ out 1 K+ in Ca2+ ATPase Ca2+ out H+ ATPase H+ out They use 1/3 cellular ATP Uphill transport Secondary Active Transport Cotransport Primary transporter (e.g. Na+/K+ ATPase) Second transporter is coupled to primary (e.g. pump Na+ in (downhill) while moving another molecule uphill) Energy of Na+ leaking back into the cell used to move other molecule In countertransport, a molecule is pulled out of the cell while another is moved downhill into the cell (or vice versa) Two molecules involved in countertransport move in opposite directions Pure water – 55.5 M Solute – 1 M glucose, 1 Osm → 54.5 M H2O 1 M NaCl, 2 Osm → 53.5 M H2O 1 M MgCl2, 3 Osm → 52.5 M H2O Osmolar shows moles of solute – 1 M NaCl → 1 M Na+, 1 M Cl- = 2 M High osmolarity, lower water concentration V1C1 = V2C2 Isotonic – same concentration of nonpenetrating solutes on either side of membrane Greater solute concentration outside – hypertonic – cell shrinks Lower solute concentration outside – hypotonic – cell swells