1. Osmosis and Water Potential Ch 7 - Principles of Transport/Osmosis and Effects on Cells Ch 36 Osmosis-Water Potential in plants

2. Problem: “Cell”: 0.03 M sucrose 0.02 M glucose Environment: 0.01 M sucrose 0.01 M glucose 0.01 M fructose Permeable to simple sugars but not dissacharides. Can we answer Q 6 a-e on page 141?

3. “Tonicity” predicts direction of water movement Hypertonic Hypotonic Isotonic

4. Effects on Cells Plant cells--What adaptations do plant cell have to deal with water balance? –Vocab: turgid, flaccid, plasmolysis Animal cells –Vocab: lysis

5. Freshwater organisms--Unity and Diversity--Dealing with Water Balance Freshwater Fish…must osmoregulate and do not drink (more later…) Protista…contractile vacuole (eg. Paramecium)

6. Ch 36 - Adaptations for Resource Acquisition Private Life of Plants excerpt: Water Transport in PlantsPrivate Life of Plants excerpt: private life of plants photosynthesis

7. Ch 36 - Transport in Vascular Plants Long distance transport by xylem (see pg 745) Tracheids Vessel elements Cell-to-cell transfer Individual cell uptake

8. Three routes of transport Apoplastic - external to cell membrane, through walls and spaces Symplastic - through cytoplasm and plasmodesmata Transmembrane - passage across cell membranes and walls Cell wall Cytosol Plasmodesma Plasma membrane Apoplastic route Symplastic route Transmembrane route Key Apoplast Symplast

9. What drives the movement of water? What is this a picture of? (hint: a major plant organ) What adaptations do plants have to control the route water takes?

10. Investigating Solute Movement Water follows ions…but how do ions become concentrated. Active Transport

11. Water Potential Water moves from higher water potential to lower water potential. Water potential= pressure potential plus solute potential

12. Model of Water Potential

13. Water potential in a Hypertonic Solution Why is the cell losing water? What is the end result- -what happens to the water potential inside/outside the cell?

14. Water potential in a hypotonic solution? What happens to the cell over time? Where is the water potential greater to begin? Which direction does the water move?

15. Now let’s go back and see why water moves up the tree?

16. Loss of water drives movement Loss of water from stomata Cohesion-tension hypothesis Movement by Bulk Flow Online - Transpiration Case Study

17. Regulation of Transpiration Where would we find guard cells ? Can you explain picture B using the concept of water potential?

18. Review the Concept of Water Potential As a Class--Case Study 36: How are Water and Solute Potentials Calculated? On your own: Osmosis Lab Bench