HE201 Study Guide - Final Guide: Passive Transport, Delta C, Active Transport
Document Summary
What do membranes do: separate material: icf / ecf, allow for exchange of material: icf / ecf. Why transport is important: obtain o2 and nutrients while getting rid of waste products. Membranes allow the transport of some substances, but not others. Non-polar molecules and small molecules: easily transported across the membrane, examples: o2, co2, fa, h2o. Large molecules, polar molecules and proteins: normally not transported, examples: glucose, proteins, na. Energy difference in the molecules on the two sides of the membrane determines the direction of spontaneous transport (passive transport) and the need for energy to move the molecule against the energy gradient (active transport) Passive transport (no energy: spontaneous, downhill movement (area of high conc area of low conc, simple diffusion is a form. Active transport (energy: not spontaneous, uphill movement (area of low conc area of high conc, mediated by transport proteins referred to as pumps. Concentration gradient = delta c = chemical driving force.
