IMED1001 Study Guide - Final Guide: Jens Christian Skou, Osmotic Concentration, Phospholipid
Document Summary
Bind specific molecules and use atp energy to transport them across phospholipid bilayers. Uses atp to move na+ and k+ against their concentration gradients. Na+-k+ pump maintains intra- & extracellular na+ & k+ concentrations. All cells have this pump uses approximately 33% of cellular energy! Pumps 3x na+ out and 2x k+ in per cycle. Net movement of +ve charge out of cell. If the cell does nothing to control osmolarity. The concentration of solutes will be higher inside than outside. The concentration of water will be higher outside the cell resulting in a constant influx of water that could lead to cell lysis. Control intracellular osmolarity by actively pumping out inorganic ions, such as na+ Prevent swelling by possession of a rigid cell wall. At equilibrium, the internal turgor pressure forces out as much water as is entering due to osmolarity differences. Secondary active transport uses a pump (atpase)
