Physiology 3120 Lecture Notes - Lecture 2: Passive Transport, Tandem Pore Domain Potassium Channel, Electrochemical Gradient

• School: Western University
• Department: Physiology
• Course: Physiology 3120
• Professor: Tom Stavraky

Document Summary

The movement of molecules due to their random thermal motion. Lecture 2: unless molecules reach absolute zero (-273 c), they"re all moving b/c of random thermal motion, water (h2o) moves at 2,500 km/h. They just don"t move very far before they bump into another molecule. B gains kinetic energy and a slows down. Glucose molecules in water: glucose molecules move around back and forth and bounce off each other and walls random thermal motion, water molecules also move around random thermal motion. Molecules move from areas of high concentration to low concentration down their concentration gradient until chemical/dynamic equilibrium is reached: chemical/dynamic equilibrium concentration is uniform throughout the solution. = no concentration gradient = no diffusion = no net movement. The driving force of diffusion is always the concentration gradient. Oxygen and glucose can move through these pores and diffuse towards cells simple diffusion. Diffusion is not an efficient transport mechanism over long distances.