Jens Kiilgaard Journal of Fluorescence, Vol.
Abstract In this experiment we are trying to find at what osmolarity of sucrose solution is isotonic with a potato cylinder. 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.
We used calipers to measure the diameter and length of each potato cylinder pre and post incubation in their given sucrose solution. The cylinders were made by using a cork borer and were undamaged and at least five cm in length. Cylinders were incubated for an hour stirring each beaker every 15 minutes.
We found that the inside of a potato was isotonic with a 0. Introduction Scientist always need to determine proper water content for normal processes to happen in plants.
Tonicity is defined as the ability of a solution to cause a cell to lose or gain water Freeman et al, There are three classes of tonicity: Isotonic, hypertonic, and hypotonic Sperelakis, A hypertonic solution, the solution has a higher amount of solutes and water tends to come out of the cell or object by diffusion Sperelakis, A hypotonic solution is the exact opposite with a higher solute concentration on the inside of a cell or object than the outside solution so the object tends to swell Sperelakis, In this experiment we will find the osmolarity of a potato cylinder by measuring its change in volume.
Materials and Methods We started by obtaining mL of distilled water and mL of each sucrose solutions and labeled each beaker appropriately.
Using a cork borer we obtained seven cylinders of potato making sure they were at least 5cm in length and undamaged.
We then cut the potato cylinders to a uniform length of 5cm and then placed them into a covered Petri dish. Using the caliper we measured the length and diameter of a cylinder to the nearest 0. We then repeated these steps for the other six potato cylinders placing each one in the appropriate incubating solution 0.
Allow the potato cylinders to incubate for 1 hr, making sure to swirl each beaker every 15 minutes. At the end of the hour record the time each cylinder is removed from its solution and do so in chronological order.
Blot each cylinder dry and use the caliper to measure the length and diameter to the nearest 0. When finished be sure to record the data. Results The potato cylinders were 5cm and length and all of them were undamaged and similar in size.
Final volume from least osmolarity to highest osmolarity in sucrose solution was Graph 2 shows the relationship between final and initial volumes at varying osmolarities of sucrose solutions graph 2.
It appears that the least change in volume in a potato was seen at a sucrose osmolarity of 0. Initial and final lengths and diameters of the seven potato cylinders can be found in table and can be compared in graph 1 table 1 graph1.
Sucrose Osmolarity and its Effect on Potato Volume.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.
exposure of cells to small and gradual changes in osmolarity. Under these conditions, cell volume remains constant even after some time of exposure to theosm otic gradient, when the external osmolarity has been considerably reduced.
This response was named “ isovol-umetric regulation” (IVR). 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.
In order for normal activities to take place, the amount of water relative to osmotically active substance (OAS) in cells must be maintained within a reasonable range. Estimating osmolarity by change in volume Introduction: Osmolarity is “The concentration of dissolved substance in a solution”.
(Freeman ) This is basically molarity except it is in different units%(1).
Be able to calculate surface area to volume ratios for cubes and spheres. How does surface area change as volume changes? Why is surface area to volume important for thermal regulation? What is the relationship between conduction and convection in relation to heat loss?
How do jackrabbits regulate and control heat loss (Fig. )? Estimaing Osmolarity by Change in Volume Essay Charles’s Law Prepared by H. A. Neidig, Lebanon Valley College, and N. Spencer, Franklin and Marshall College PURPOSE OF THE EXPERIMENT Establish the relationship between the volume of a gas and the temperature of a gas at constant pressure.