BIOA01H3 Lecture Notes - Lecture 9: Endosperm, Meristem, Casparian Strip

• School: UTSC
• Department: Biological Sciences
• Course: BIOA01H3
• Professor: Steve Joordens

Document Summary

Sugar: runs from phloem of the year down the shoot. H2o: runs from the xylem of the year up the shoot. Slide two water and sugar transport through plants. Water transport through xylem: hypotheses on mechanisms of water transport, synthesis; total plant water transport, control of water transport. Three hypotheses: capillary action, root osmotic push, transpiration. H2o moves upward in a small tube through adhesion to tube walls and cohesion between h2o molecules. Capillary action at max can push water up a distance of one meter: however, capillary action is important to maintain a string of water up the xylem. Slide six high solute concentration in root hairs. Plant actively pumps ions into root cells through atp. Pushes water up a distance of 100+ meters. Intracellular leaf space: sun turns liquid h2o into gaseous h2o which facilitates movement up xylem. Gaseous h2o pressure in air < gaseous h2o leaf: gaseous h2o diffuses out of stomata.