Ben Zaré 9MK Biology Investigation - Osmosis in Potato Cells 9/7/04 Section 1 Planning Aim What is the aim of your experiment? What do you want to find out? The aim of this experiment is to investigate how potato tissue changes when placed in sucrose solution of different concentrations. Therefore, I want to find out if and how osmosis differs, when the concentration is changed. Variables What is the variable you are going to change in the experiment? The input variable of this experiment (i.e. the variable to change) will be the concentration of sucrose solution present in the test tubes, which the potato samples will be placed into. What is the variable you are going to measure in your …show more content…
As was mentioned, only one input variable will be used (this being the concentration of the sucrose solution in the test tubes). This means that, in order to make sure this is a fair test, every other variable in the experiment must be kept constant and uniform. Therefore the same equipment will be used throughout. This will include test tubes with the same volume of solution; weighing machines tested and made set to begin on zero (electronic). The experiment will be conducted in, as close as possible, the same temperatures (allowing for very slight variation). Also any volumes of sucrose solution measured in the experiment will be measured accurately using measuring cylinders. Observations will not be taken into consideration in planning because none of the results require observations, only what the weighing machine reads. Therefore, there can be almost no fault when it comes to recording the results. Trial Experiment Results Once you designed your experiment check to see it all works by taking a couple of results and recording them. Solution Volume sucrose sol Volume water Molarity (concentration) 1 0cm³ 20cm³ 0m (0%) 2 4cm³ 16cm³ 0.2m (20%) 3 8cm³ 12cm³ 0.4m (40%) 4 12cm³ 8cm³ 0.6m (60%) 5 16cm³ 4cm³ 0.8m (80%) 6 20cm³ 0cm³ 1.0m (100%) (Diameter of cork borer: 2mm) Solution Length start (mm) Length after (mm) Length Change (mm) 1 40 42.0 +2.0 2 40 40.0 0.0 3 40 38.5 -1.5 4 40
Procedure: Measure the volume, mass, length and temperature of a variety of items. Create dilution of sugar water.
Aim: To find the concentration of a potato cell cytoplasm compared to sucrose and salt. I mainly was looking to see how concentration of salt/sucrose affects the mass of the potato cores.
Purpose: To determine the concentration of solute in the potato’s cytoplasm by measuring the change
Osmosis is the diffusion of water across a membrane to create an equilibrium between the levels of concentration of a solute both inside and outside the cell. In this case the solute will be sugar as the potato core will be immersed in sucrose solution.
The next step in this lab is to rinse the Erlenmeyer flask with distilled water down the drain and then repeat the experiment, this time adding 10 ml of 0.10M KI and 10 ml of distilled water to the flask instead. The flask should again be swirling to allow the solution to succumb to the same temperature as the water bath and once it has reached the same temperature, 10 ml of 3% H2O2 must then be added and a stopper must be immediately placed on the flask and recording should then begin for experiment two. After recording the times, the Erlenmeyer flask must then be rinsed again with distilled water down the drain. After rinsing the flask, the last part of the lab can now be performed. Experiment three is performed the same way, but instead, 20 ml of 0.10 ml M KI and 5 ml of distilled water will be added and after the swirling of the flask, 5 ml of 3% H2O2 will be added. After the times have been recorded, data collection should now be complete.
Osmosis is defined as the tendency of water to flow through a semipermeable membrane to the side with a lower solute concentration. Water potential can be explained by solutes in a solution. The more positive a number is more likely it will lose water. Therefore should water potential be negative the cell the less likely it will lose water. In using potatoes the effects of the molarity of sucrose on the turgidity of plant cells. According to Clemson University, the average molarity of a White potato is between .24 M and .31 M when submerged in a sorbitol solution. This experiment was conducted with the purpose of explaining the relationship found between the mass in plants when put into varying concentrations of sucrose solutions. Should the potatoes be placed in a solution that contains 0.2M or .4M of sucrose solution it will be hypotonic and gain mass or if placed in .6M< it will be hypertonic and lose mass instead. Controlled Variables in this lab were: Composition of plastic cups, Brand of Russet Potatoes, Brand of Sweet Potatoes and the Temperature of the room. For independent variable that caused the results recorded it was the different Sucrose concentrations (0.0M, 0.2M, 0.4M, 0.6M, 0.8M, 1M). The dependent variable was the percentage change from the initial weighs to the final. The cup with .4 molarity was the closest to an isotonic solution and was used as the control group for the lab. Water potential is the free energy per mole of water. It is
The aim of the sixteenth of November experiments was to observe how three different solutions with various sucrose concentration influenced osmosis in relation to three onion cells and the impact on the cells structure.
Effect of Sucrose Solution on Osmosis Aim: The aim of the experiment is to show how varying the concentration of sucrose solution affects osmosis by changing different molar solutions of sucrose and water and how it affects the potato. Introduction: In this investigation I will be exploring the effect of varying concentration of sucrose sugar solution on the amount of activity between the solution and the potatoes. Osmosis is the movement of water molecules across a partially permeable membrane from a high water concentration to a low water concentration.
However one beaker received 100 mL of Deionized water with a molarity of 0.0. Afterwards a cork borer was pushed through the potato and was twisted back and forth. Once the borer was filled it was removed from the potato. Pushing the potato cylinder out of the borer, this this step was repeated six more times in order to get seven undamaged potato cylinders. Using a sharp razor blade, the potato cylinders were both cut to a uniform length of about 5cm, and were removed of their potato skins. The potato pieces were also cut in half to give the cells a greater surface area in which it was easier to absorb the solution. After the cylinders were weighed on a balance and the data was recorded in Table 4. Using the razor blade each potato was cut lengthwise into two long halves. Then the potato pieces were transferred to the water beaker and the time they were submerged was recorded. This step was repeated for all potato cylinders in which the pieces were placed in solutions 0.1 to 0.6 M. The potatoes were incubated for ninety minutes. At the end of the incubation period the time was recorded. Then the potato piece was removed form the first sample. Next potato pieces were weighed the and the final weight was recorded in Table 4. This procedure was repeated until all samples had been weighed and recorded in the chronological order they were initially placed in the test solution. Afterwards the table was completed by recording the
The purpose of this experiment was to investigate the effect of the change in concentration of sucrose on the rate of osmosis in cylinders of potatoes.
Data: Effect of Solute Concentration on Osmosis in Potato Cells (for the 6 groups of our class)
This experiment was used to examine the hypothesis that: Osmosis is dependent on the concentrations of the substances involved.
In this lab we are going to discovery how osmosis works using a semi-impermeable membrane a potato slice. Osmosis is known as the movement of water in and out of a cell. To understand how this works we must understand two terms. Hypotonic means the environment has less solutes compared to the inside of the cell. Hypertonic means that the environment has more solutes compared to the inside of the cell. With osmosis water will always move from hypotonic too hypertonic. So the question is will water move into the potato or out of the potato? Will these results change when placed in different morality of salt water? To calculate these results, we will measure the mass of potatoes cut into equal sizes then soak these potato slices in different morality of NaCl for thirty minutes and measure the mass change in each potato slice.
The purpose of this lab is to test the effect of osmosis on cucumber slices. If a cucumber slice is placed in a hypertonic solution, then the mass of the cucumber slice will decrease. Whereas, if
As we can see in Figure’s 1.2 and 1.3, when there was no sucrose solution, the potato increased in weight. This is due to the fact that the sucrose solution was hypertonic in comparison to the potato slice. Through osmosis, the solution moved along the concentration gradient and into the potato slice making it hypotonic. When there were higher concentrations of sucrose solution, the potato decreased in weight. This is due to the fact that the potato was hypertonic in comparison to the potato. Through osmosis, sucrose from the potato moved along the concentration gradient out and into