Carrot Lab
Abstract: In this lab, carrots were placed in sugar solutions of varying sugar concentrations. The effects of osmosis and cellular diffusion are going to be observed as the carrots gain or lose weight in the solutions over the period of time. The weights of the carrots will be measured after 30 min, and again after 24 hrs. The purpose of this lab is to find out how the cells in carrots will react to various sugar concentrations. The idea is that the cells will absorb the water and become heavier and supple.
Introduction: One of the most common types of passive transport of materials is called diffusion (Ward’s Natural Science). Another common type of transport is osmosis. Osmosis is the movement of water through a cell membrane.
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Because of how much water the carrots should absorb, they will increase in mass because the cells will be full of the water.
Materials: 6 baby carrots, identical
6 sugar solutions
Timer
Beakers
Scale
Sugar and Distilled Water
Marker Dye
Variables: In this lab, the independent variable is the sugar concentration. The dependent variables are the weights of the carrots. The controlled variables would be the amount of water, the temperature in the room, carrot size, the time the carrots are in the solutions, etc. The experimental groups are the varying sugar solutions. The control group is the carrot is the distilled water.
Procedure:
Put 1 carrot in each solution.
Wait 30 min.
Record the weight of the carrot and see if anything changes.
Leave the carrots in the solution for 24 hrs.
Record observations. Did the carrot’s mass change at all?
Observations and Data:
Table 1. Carrot weights Before and After Soaking in Sugar Solutions.
Sugar Concentration (M)
Carrot Weight (g)
Before
After 30 min
After 24 hr
1.0 (A)
12.2
12.2
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The hypothesis tested was rejected. It stated that all the carrots would increase in weight. Not all of the carrots increased in mass. Some of them actually lost weight, in fact (cups A, B, and C). The carrots that lost weight were in a hypertonic solution (there were more molecules outside of the cells), or the carrots in the highest sugar concentration. The water moved out of the cell because of osmosis. Only water moves through the membrane, not sugar particles because they are too big (not permeable to the membrane) (Baker, et. al., 2012). The solution that had a low concentration of sugar was a hypotonic solution. The carrot gained mass because water moved in the cells to dilute the solutes (cup D). Cups E and F were isotonic solutions. There was no net movement of water because there was equal amounts on both sides of the
Investigation to Find the Water Potential of a Root Vegetable Introduction Water potential is the tendency of water molecules to move from one place to another. Osmosis is the movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane. I will be investigating the water potential of a carrot to find out at what concentration of salt solution (molar dm-3) equilibrium can be sustained between the net movement of water molecules in to the carrot cells, and the net movement of water molecules out of the cells, therefore finding out the water potential of the carrot, and at what concentration of salt solution the movement of water molecules ceases, and what concentration the water is at inside the carrots cells. I will need to include and explain the relevant AS knowledge demonstrated by this investigation. This includes ideas about osmosis, explaining also how this can affect the structure of plant cells, and showing extremes such as plasmolysis.
Investigating Osmosis In A Potato Introduction: "Osmosis is typically defines as the flow of one constituent of a solution through a membrane while the other constituents are blocked and unable to pass through the membrane. Experimentation is necessary to determine which membranes permit selective flow, or osmosis, because not all membranes act in this way. Many membranes allow all or none of the constituents of a solution to pass through; only a few allow a selective flow. In a classic demonstration of osmosis, a vertical tube containing a solution of sugar, with its lower end closed off by a semi-permeable membrane, is placed in a container of water. As the water passes through the membrane into the tube, the level of sugar solution in the tube visibly rises.
Osmosis in Potato Chips Preliminary Experiment to investigate Osmosis 1M Sugar 50:50 0M (water) Initial mass 2.40 2.05 2.34 Final mass 2.01 1.85 2.43 Change in mass -0.39 -0.21 0.09 % change in mass -12.5% -10.5% 3.84% Evaluation From doing our preliminary experiment it enables us to gain a better result for our real experiment. From this experiment we have learnt a few things through trial and error, for example. If we had used a wider variety of concentrations, our results would have been more accurate. By using a syringe to measure the solution we would have also got a more accurate result. We could have also weighed the potato chips more accurately so they were roughly the same size with no skin.
...ers doing this experiment. Furthermore, only one variable was changed (concentrations of glucose) while the other variables were controlled.
Osmosis in Potato Tubes Osmosis: Osmosis is the movement of water molecules through a semi-permeable membrane from a high concentration to a low concentration. Diagram: [IMAGE] [IMAGE] Aim: To see the effects of different concentration of sugar solution on Osmosis in potato tubes. Key factor: In the investigation we change the sugar solution from: 0%-10%-20%-30%-40%-50% this is the independent variable; the dependant variable is the change in mass. Prediction: I predict that all the potato tubes in pure water or low concentration sugar solution will swell because water enters their cells by osmosis.
In this lab we tested osmosis through a semi permeable membrane using dialysis bags (SCC Science Division, 2014). We also looked at osmosis in living cells of potatoes. When water is moved through a semi permeable membrane that is called osmosis. Passive transport is when molecules move with the concentration gradient across the membrane with no cellular energy used. Osmosis and diffusion are examples of passive transport. There is also active transport which is when molecules move against the concentration gradient and uses energy in the form of ATP (Urry, Cain, Wasserman, Minorsky, Jackson, & Reece, 2014). There are three types of conditions that deal with osmosis that will be found in this experiment: isotonic, hypertonic, and hypotonic solutions. Isotonic is when the concentration of a solute is identical outside of the cell and inside of the cell. Hypertonic is when the concentration of solute is higher outside of the cell than inside of the cell. Hypotonic is when the concentration of a solute is less than the solutions outside the c...
Potato and Osmosis Investigation PLANNING: (P) Some background Information: Water Potential and Living Plant Cells Plant Cells in Pure Water: If plant cells are placed in pure water (a hypotonic solution) water will initially move into the cells. After a period of time the cells will become turgid. Turgor pressure is the pressure exerted against the cell wall by contents of the cell. At first most water movement is into the cell. As the turgor pressure increases water will begin to diffuse out of the cell at a greater rate, eventually equilibrium will be reached and water will enter and leave the cell at the same rate.
Variables Description: Constant Variables: ------------------------------------------ These stay the same all the way through the experiment and are the fair test rules. In this experiment they are that the amount of sucrose solution used must always me 40.0ml.
However, the solution could be more water than salt so the water from the solution could be more concentrated than the water inside the potato cells. If so then In theory the water in the solution should diffuse into the potato. cells and increase in mass. Apparatus: Potato to perform the experiment on. Thin metal tube to cut potato chops with.
Most cell membranes are like that, being permeable to water and some solutes only. Osmosis is therefore the diffusion of water through a partially permeable membrane. The basic principles of diffusion apply here.
It was stated in the hypothesis that, “If cucumber slices are placed in water, ten percent sugar solution, and twenty percent water solution, then the cucumber in water will be isotonic (have the same measurement), the cucumber in the ten percent sugar water will become hypertonic (have smaller measurement), and the cucumber in the twenty percent sugar solution will be very hypertonic (even smaller). This is because of the process of osmosis and how things travel on the concentration gradient.” To test the hypothesis, three cucumbers were placed in three different solutions after being tested for their volume and mass. One solution held only water, another had 10% sugar, and the last had 20% sugar. After letting the cucumbers soak in each solution, their volume and mass was tested again. As shown in the table, the solution with only water had made the cucumber hypotonic. The volume was increased .16 and the mass increased .36g. In the 10% and 20% sugar solutions, the cucumber became hypertonic. The volume and mass of each cucumber had decreased. In the 10% solution, the volume went down by .16 and the mass went down .47g. In the 20% sugar solution, the volume decreased by .10 and the mass by .9g. The data collected from the lab proved our hypothesis was correct. One way to improve this lab would be to make sure the cucumbers were all the exact same size. This would make the data more accurate and easier to
The Effect of Solute Concentration on the Rate of Osmosis Aim: To test and observe how the concentration gradient between a potato and water & sugar solution will affect the rate of osmosis. Introduction: Osmosis is defined as, diffusion, or net movement, of free water molecules from high to low concentration through a semi-permeable membrane. When a substance, such as sugar (which we will be using in the experiment we are about to analyse), dissolves in water, it attracts free water molecules to itself, and in doing so, stops them from moving freely. The effect of this, is that the concentration of (free) water molecules in that environment goes down. There are less free water molecules, and therefore less water molecules to pass across a semi-permeable membrane, through which sugar molecules and other molecules attached to them are too big to diffuse across with ease.
The data in both Table 2 and Graph 1 show that as the concentration of sodium chloride (%) is increased from 0% to 10% when there is a significant increase in the % change in mass, thus also the rate of osmosis. Between concentrations 0% and 2% there was a rapid % change in mass. At 0% NaCl the % change in mass was +1.63% indicating that the potato piece had gained water because the concentration of solute must have been higher in the potato than in the solution. The % change in mass at 2% NaCl concentration was -8.82%, the negative indicates that the potato piece had lost water as the concentration of solute was higher in the solution than the potato piece. From 2% to 4% NaCl solution the %change in mass was slightly less rapid but still had an increase from -8.82 to -14.7, respectively. The graph had a slower decreasing trend from 4% NaCl solution onwards, this can be seen from the gradual plateau of the graph. The slowest increase in %change in mass of -0.04% was between 6% to 8% valued at -16.5% and -16.9%, respectively. The % change in mass increased slightly from -16.9% to -17.5% between 8% to 10% NaCl concentration. This suggests that the rate of osmosis had begun to stabilize and may be the result of the concentrations of both the
The important mechanisms are diffusion, osmosis, and active and passive transport. Through simple diffusion, small noncharged molecules or lipid soluble molecules pass between the phospholipids to enter or leave the cell, moving from areas of high concentration to areas of low concentration. For polar compounds energy is needed in the form of ATP to enter the cell, this is called active transport.
== = This experiment is based on the concept of Osmosis. Osmosis is the diffusion of water molecules from a region of high water concentration to a low water concentration through a semi permeable membrane (in this case, the cell potato cell membrane). The cell walls of the potato cells are semi permeable meaning that water molecules (which are small) can fit through but other bigger molecules such as glucose cannot pass through. The water molecules can flow both ways through the membrane, letting molecules both in and out.