We then cut the potato cylinders to a uniform length of 5cm and then placed them into a covered Petri dish. In this experiment we will find the osmolarity of a potato cylinder by measuring its change in volume.
Fill a pneumatic trough with ice and water. Be sure that the pinch clamp is not attached so tightly to the rubber tubing that the rubber tubing is closed. Any water present in the flask will cause a large error in the calculated volume-to-temperature ratio.
Further research should be done on other vegetables or plants to find their ideal water content and isotonicity. Measure the temperature of the ice water during this time. There are three classes of tonicity: If the pressure is in torr record this pressure on your Data Sheet 6.
Be sure the Erlenmeyer flask is thoroughly dry. You will find the volume of air in an Erlenmeyer flask at two different temperatures.
Convert the barometric pressure to an equivalent pressure in torr, if your pressure reading was made in units other than torr, using Equation 4 or 5. At the end of the 6 min of heating, the boiling water in the bath was only in contact with the lower portion of the flask.
Graph 2 shows the relationship between final and initial volumes at varying osmolarities of sucrose solutions graph 2. Measure the volume of water in the flask to the nearest 1 mL by pouring the water into a dry, mL graduated cylinder.
Tonicity is defined as the ability of a solution to cause a cell to lose or gain water Freeman et al, If the pressure is in inches or mm of Hg, record this pressure on your Data Sheet 5.
Materials and Methods We started by obtaining mL of distilled water and mL of each sucrose solutions and labeled each beaker appropriately. The potato is hypertonic when compared to the sucrose solution at 0. This observation was first made by Jacques A. Use a mL graduated cylinder to pour about — mL of water into a mL beaker.
Allow the potato cylinders to incubate for 1 hr, making sure to swirl each beaker every 15 minutes. Divide the volume of hot, dry air 4 by the Kelvin temperature of the boiling water Keep the flask in the boiling-water bath for at least 6 min.
Insert a thermometer into the boiling-water bath for 3—4 min and measure the temperature of the water. The cylinders were made by using a cork borer and were undamaged and at least five cm in length.
The number appearing in parentheses indicates the line on your Data Sheet on which that data should be entered. Dry a mL Erlenmeyer flask by wiping the inner and outer surfaces with a dean, dry towel. At the end of the hour record the time each cylinder is removed from its solution and do so in chronological order.
Get Full Essay Get access to this section to get all help you need with your essay and educational issues. Be careful while removing the hot flask from the boiling water. Do not burn yourself with the steam rising from the boiling water.
Use the utility clamp to remove the flask from the boiling water. Record this temperature on your Data Sheet 1. Isotonic, hypertonic, and hypotonic Sperelakis, Post-Laboratory Questions Name, Sect.
If diffusion will not occur between the potato and sucrose solution at the same osmolarity then there will be a low percentage change in weight and volume between initial and final volume of the potato cylinder. Next, the flask will be immersed in cold water without any loss of air, and water will rush into the flask as the gas contracts and occupies a smaller volume.
We used calipers to measure the diameter and length of each potato cylinder pre and post incubation in their given sucrose solution. In the ice-water bath, the air is collected over water. Describe the safety precautions you must take when removing the flask from the boiling—water bath.
Do not allow the flask to touch the bottom or the sides of the beaker. Pre-Lab oratory Assignment 1.Estimating Osmolarity by change in weight Abstract Water flows in and out of cells in an attempt to attain a state of equilibrium.
The concentration of solutes to solvent in. "Estimating Osmolarity By Change In Volume Of Potato Tuber Tissue" Essays and Research Papers Estimating Osmolarity By Change In Volume Of Potato Tuber Tissue Estimating Osmolarity by Change in Weight Abstract Optimum water content for normal physiological processes in plants is crucial.
solutions with various molarities for 45min and their volume and weight change percentages were taken. Results showed that potato cores in MM solutions have gained more weight and volume after incubation period while cores in MM solutions have decreased their weight and volume. Graph 3: Change in Initial and Final Volume of Potato Cylinders at Different Sucrose Osmolarities [pic 3] 5.
Discussion. If diffusion will not occur between the potato and sucrose solution at the same /5(1). Estimaing Osmolarity by Change in Volume Essay Sample The volume of a gas at constant pressure increases when the temperature of the gas is raised. This observation was first made by. Estimating Osmolarity by Change in weight volume By Nadine Boyd 09 23 13 BIO H50 Cara Denise Sean All plants have living cells.
Osmosis is a process.Download