BIOL 111 Lecture Notes - Lecture 8: Stoma, Osmosis, Transpiration

• School: McGill University
• Department: Biology (Sci)
• Course: BIOL 111
• Professor: Rudiger Krahe

Document Summary

Biol 111- lecture 8 uptake and transport of materials in plants. Inorganic materials such as chemical nutrients are obtained from soil and water: the processes of acquisition and distribution of materials involve their transportation. Transport processes: transport by bulk or mass flow (driven by pressure difference between 2 ends of path, diffusion (due to inherent thermal energy of molecules. Involves no applied force, concentration gradient provides direction: osmosis (special case of diffusion. Concentration gradient provides the direction: facilitate transport by carrier proteins, membrane channels and by energy requiring pumps. This type of flow is measured in total volume of flow per unit time (l/min) It is driven by the pressure difference between the 2 ends of the tube and is directly related to 4th power of tube"s radius. Diffusion is movement of molecules due to their internal thermal/kinetic energy. Osmosis is a special case of diffusion: a semi permeable allows solvent but not solute molecules to pass through.