BIOL 260 Lecture Notes - Lecture 10: Plant Cell, Semipermeable Membrane, Bidirectional Traffic
Document Summary
Discuss how plants regulate transpiration and water loss. Describe how solute concentrations and turgor pressure control water potential and flow in plants. Make predictions about relative plant transpiration rates under different environmental conditions. Describe the pathways of water and nutrient transport through xylem, including the tissues and structures involved and the chemical/physical driving forces. Outline the experimental evidence in support of the cohesion-tension mechanism of plant transpiration. Discuss the pressure-flow model of sugar transport in phloem, including the tissues and structures involved and the chemical/physical driving forces. Bulk flow: the way to transport large quantity efficiently to remote areas. Through the phloem (important for sugar transport), and xylem (important for mineral and water transport) Circulatory systems are driven by positive pressure and negative pressure systems. Harder to generate positive pressures because plants do not have muscles - plants use osmosis. Plants cannot use muscles - use transpiration/evaporation (generates tension that causes negative pressures in plants)
