2) In “Chardakov method for water potential measurement” experiment, you find that M solution has not been changed by water loss or absorption by the. Chardakov Technique. Plant Physiology. UNI. Incubating tissue in solution. Pre- incubation. Incubation. Post-incubation. Save for later measurement. Did solution change concentration? Solutes stay the same If water left or entered tissue –Water also entered or left solution –Solution becomes more dilute or.
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Investigating osmosis: measuring the water potential of a potato cell
In this method, tissue samples are weighed before and after mefhod in a series of solutions of known osmotic water potential. What is the water potential calculated by this method? Which method do you think will be more accurate?
Dispense 10 mL of water or sucrose 0. Work quickly to minimize evaporation and keep the tissue wrapped in a moist towel. Published by Sabrina Grant Modified over 2 years ago. Osmosis diffusion of water through a selectively permeable membrane Membrane X is permeable to water but not to protein Which side has the highest concentration.
The solution gains or looses water depending on the water potential of the tissue. Record your data in Table 2. Be sure not to include any fragments of the skin.
This occurs when the apoplast becomes infiltrated with water and solutes. Which methox more accurate? Immerse the pipette in the water that previously had tissue sections in it until the tip is approximately at the center of the tube. Registration Forgot your password?
Work quickly to minimize evaporation and keep the tissue wrapped in a moist towel.
About project SlidePlayer Terms of Service. Share buttons are a little bit lower. Be sure to use a different pipet for each dye stock. Incubating tissue in solution Pre-incubationIncubation Post-incubation Save for later measurement. No change in density, concentration No net water movement Tissue and solution were at the same WP If we can find this solution concentration —We can find the tissue WP.
An alternate method to determine his point requires performing methoe regression analysis of the best fit line of your data. Draw the best fit line meethod your data.
Use a cork borer to prepare at least 27 charxakov tissue samples from the potato. Record the temperature of the solutions Table 1 Using a Pasteur pipet, remove a small amount of water dyed with methylene blue to dye the sucrose solution, dip a dry probe into methylene blue powder and then mix. It is assumed that solute movement between tissue and solution is negligible. Boy, Oh Buoyancy Does it Float?
Change in weight of potato cores incubated in sucrose solutions. Then remove the tissues, gently blot on paper towels and reweigh. Divide by 10 6 to convert to MPa. Slowly release a drop of the methylene blue solution from the pipette and note whether the drop of the dye sinks, disperses, or floats to the surface in this solution and subjectively estimate whether it does so rapidly or slowly.
Incubate the cores for at least 1. Cell Transport The movement of molecules can be either passive no energy or active needs energy depending upon the membrane structure and concentration. We chaedakov you have liked this presentation. Metbod Any substance that can change shape or flow easily. Hypertonic Concentration with higher solute concentration and less water concentration Hypotonic lower solute concentration and more water concentration.
Cut them to the same length with a razor blade ca.
Water potential values determined by this method may be slightly more negative than those obtained cgardakov the Chardokov method. Cut them to the same length ca.
If necessary, add more of the appropriate solution to completely submerge the cores but the final volume in each tube must be the same. Two ways to move water Bulk flow Osmosis Both move water from high energy to low Differences —Source of energy difference. Incubate the cores for 1.
Weigh two or preferably three cores, record your data in Table 2 and then place the cores in one of the test solutions.
Record your results Table 2 and repeat this procedure for each of the sucrose solutions. What is the water potential of potato tissue?
Then, the percent change in weight of the tissue is plotted versus solution concentration or osmotic potential. Pour off the solutions into a set of empty, correspondingly labeled tubes.
In contrast to the Chardakov method which analyzes changes in solution density after incubation, this technique monitors tissue weight changes.
What would happen to The size of the tissue? Use a cork borer to prepare at least 27 uniform tissue samples from the potato. In both techniques, tissue samples are incubated in a series of solutions of known osmotic water potential. The water potential measured by this technique should be the same as that obtained the Chardakov method.
Repeat for all solutions. At this point, the water potential of the solution equals the water potential of the potato cores.