BIO203H5 Lecture Notes - Lecture 4: Water Potential, Osmometer, Distilled Water
Document Summary
Human civilization owes everything to 6 inches of soil & the fact that it rains . Water relations: key concepts: water relations, plant cells, water potential, movement, whole plant, uptake, transport, loss. Plant shape & growth: less than full amount of water in the many cells of the leaf is responsible for wilting, water loss by transpiration also regulates temperature, cool grass on a hot day, cooked alpines. Cell elongation & growth: movement of water into cell and into vacuole driving cell expansion. Cell only needs a small amount of additional cytoplasm during expansion: microtubules & actin. Pressure potential ( p: pure water has a water potential of 0, water gains energy under pressure and becomes more positive, difference between potential of pure water & water under pressure is ( p) Osmometer 2: water on both sides of the selectively permeable membrane, salt/sugar dissolved in tube, water moves freely but solutes are confined to tube.
