BIOA02H3 Lecture Notes - Lecture 9: Semipermeable Membrane, Root Hair, Capillary Action

• School: UTSC
• Department: Biological Sciences
• Course: BIOA02H3
• Professor: Ivana Stehlik

Document Summary

Basic plant needs: movement of water: through phloem from the roots through the xylem from the. In order to produce sugar, plants need: carbon dioxide, light, water. Need water and oxygen for other metabolic activities. 3 hypothesis: capillary action : 1 meter, root osmotic push : 3 meter, transpiration : 100+ meters. Osmosis (osmotic pressure: water diffusion through semi-permeable membrane (ex. Cell wall) from a low concentration solution to a high concentration solution (salt, minerals) until concentration on both membrane sides are the same. Semi-permeable: water can move through (large enough opening to let water), but not minerals (not big enough pores) Removal of water from a: continuous water column can draw water to huge heights: 130 m (tallest redwood: it cannot rise since gravity becomes too strong and pulls it back down (thus trees cannot grow forever) Limited ability of water: to evaporate, and physical force of gravity pulling downward on water column.