Osmosis in Potato Cells
Aim
===
The aim of my experiment is to investigate the effect of glucose
solution on osmosis in potato chips. I shall be observing how the mass
of the potato chip changes in different concentrations of glucose
solutions. Simply, will the effect of the action of osmosis be
affected by the concentration of the solution?
Introduction
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Knowing that osmosis (a diffusion of water) will occur across a
semi-permeable membrane whenever there is a difference between the
water concentrations on the two sides of the membrane, and knowing
that when this happens to cells they will either become turgid if
water flows into them, or plasmolysed if water flows out of them, and
thus change their volume, we want to test the hypothesis that:
If the concentration of a solution into which a cylinder of potato is
placed is greater than a certain level the cylinder will contract, and
if the concentration is less than that level it will expand.
Apparatus
For the experiment I will require:
Potato - to use to show osmosis
Borer - to cut circular potato pieces
Scalpel. (To allow us to make our own).
Solutions of varying strengths, a solution of a known strength and
distilled water. (To allow us to make our own). - To put potatoes in,
5 different concentrations
Test-tubes (5) - to put the solution in
Ceramic tile
Pen, Paper and ruler - to record results
Measuring cylinders
Electronic balance - to weigh potato pieces, gives a more accurate
result than normal balance
Kitchen towel - to dry potato pieces, so water does not make them
weigh more, as this ...
... middle of paper ...
...occurred, the range of
results appeared too low. However, although this is apparently an
anomalous result, it could have been caused by either experimental
error - more significant when a small number of results are used, or a
difference in the potato for those cylinders. Either of these would
easily be recognized if a larger number of results were collected and
used.
For future experimentation we could repeat this experiment using a
range of solution strengths very close to the value discovered here of
sap osmolarity, to define more exactly its true value. We could also
extend the experiment to use tissue samples from other plants, to
discover whether the hypothesis is also correct for other tubers, and
even for other plant tissues. We would then also be able to compare
osmotic pressures inside different plants.
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.
Conclusion In my conclusion, the potatoes with the lowest concentration gained the most mass, and would become hard relating back to the Turgor theory I stated earlier. In contrast to this, the potatoes in the most concentrated solution lost the most weight thus becoming plasmolysed and limp also relating back to the background I have mentioned earlier. Evaluation In general the experiment was succesful the results were consistent and also were in accordance with the theories made at the start.. The experiment could have been improved by: · More subjects used instead of potatoes · More potatoes · Wider time ranger · Different molarities Using this variety of methods could have improved the experiemnt, however I was generally satisfied with the results of this osmosis experiement.
* Note the mass down in the table at the end of the first page.
Factors Affecting Osmosis in Potato Tissue Introduction: I am going to design and modify an experiment used to show osmosis in potato chips in different concentrations of sucrose solution. I am also going to investigate on how potato chips change in volume and weight when placed in different concentrations of sucrose solution. I will also conduct a preliminary experiment before my final experiment. Aim: To investigate the effect of different concentration of sucrose solution on potato chips. Hypothesis: I would expect the potato chips to turn flaccid when they are placed in a strong sucrose solution because the water from within the cells will diffuse out leaving the potato flaccid.
Investigate the Osmosis of Potato Cells in Various Salt Solutions. Introduction I have been asked to investigate the effect of changing the concentration of a solution on the movement of water into and out of potato cells. I will be able to change the input of my experiment. The input variable is the concentration of the solution.
If the concentration of sucrose increases, then the mass of the potato will decrease. However, if the concentration of the solution in the beaker is less than that of the potato (such as distilled water), then the mass of the potato will increase. So, as the concentration of sucrose increases the rate of osmosis increases.
Water Potential of Potato Cells Aim: To demonstrate the Water Potential of Potato Cells. Objectives: · To show the water potential of potato cells using various measured concentrations of a sucrose solution and pieces of potato. · To record and analyse data to verify observed results. · The method and procedure was carried out as per instruction sheet. Observations: The experiment shows that the lower the concentration of the sugar solution, in the Petri dish, the mass of the potato increased.
the same way as it does potato. I would also widen the range of sugar
So what is happening is water is moving from a high concentration, i.e. a dilute solution to a more concentrated solution. Preliminary Work on Osmosis I am going to test carrots in a small osmosis experiment to see how the experiment works with carrots and salt solution and water. Variables 1) Temperature - Keep the same 2) Number of days left soaking - Keep the same 3) Size of beaker - Keep the same 4) Size of carrots - Keep the same 5) Concentration of salt solution -
Knife to cut the potato to the correct shape and size for reasons. stated in the method. Tile to not score any school surfaces. Test tubes to hold the potato and solution in. Beaker to alter solution concentration.
Potato 2. Standard sugar solution (1molar) 3. Wash bottle 4. Test tubes and test - tube rack 5. Cork borer-size (4mm diameter) 6.
Investigating The Effect Of Concentration Of Salt Solution On The Mass Of Potato Chips Aim: The aim of this investigation is to see whether the amount of salt solution affects the mass of the potato chip Hypothesis: In the solution below, water will diffuse from the dilute solution into the concentrated solution through the process of osmosis. Therefore the dilute solution level will fall and the concentrated level will rise Line Callout 2: Disapproved (is unable to go through the semi permeable membrane O Line Callout 2: Approved (is able to go through the semi permeable membrane P Salt solution Water [IMAGE] When a substance such as salt dissolves in water, the substance's molecules stick with some of the water molecules, so the concentration of the water molecules decreases. When the water molecules are the same concentration on both sides of a semi permeable membrane and salt is dissolved into one of them, osmosis will occur as shown in the diagram below.
Determining the Concentration of the Cell Sap in Potato Storage Tissue Aim: To determine the concentration of the cell sap in potato storage tissue. By using Osmosis, determine what the sugar concentration of cell sap is. Prediction I predict that the potato segment in the distilled water will definitely gain in weight because the solution outside it has a much higher concentration of water then in the cell sap meaning Osmosis will occur and the potato segment take in water. I predict that 0.2M sugar solution will also gain weight because it still has quite a high concentration of water outside the potato. The potato in the 0.4M solution will gain weight but the potato in the 0.6M and 0.8M solutions will lose weight.
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.
The Effect of Water Concentration on the Mass of Potato Tissue Aim: The aim of this investigation is to discover the effect of water concentration on the mass of potato tissue, and also to investigate the movement of osmosis through potato tissue. Scientific Knowledge: When a substance such as a sugar dissolves in water, the sugar molecules attract some of the water molecules and stop them moving freely. This, in effect, reduces the concentration of water molecules.