Osmosis Investigation
The Problem
When a piece of fresh beetroot is left to stand in a beaker of cold
distilled water, very little pigment is released from the beetroot.
When, however, a similar piece is placed into a beaker of hot water,
pigment release happens more quickly and the surrounding water soon
becomes coloured red.
A possible explanation for these observations could be that the
structure of the plasma membrane is affected by temperature. As
temperature rises, the damage to the plasma membrane will result in an
increase in the amount of pigment released from the beetroot cells.
The Task
Design an investigation based on these observations and the
explanation suggested.
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Equipment Needed
The following equipment will be required to perform this experiment:
1 beetroot
1 cork borer (size 4)
30 test tubes
1 timer
1 scalpel
1 ruler
1 measuring cylinder
1 colorimeter
16 cuvettes
1 white tile
2 thermometers
5 water baths – set at temperatures 30ºC, 40ºC, 50ºC, 60ºC, 70ºC
Distilled Water
Paper towels
Independent Variables
In this experiment there are several possible independent variables
that could be changed, these consist of:
* The surface area of the beetroot cylinder
* The volume of the beetroot cylinder
* The temperate the experiment is done at
* The time the beetroot cylinders are left in the water
* Amount of water used
* Age and condition of beetroot used
The independent variable that I will be changing is ‘the temperature
the experiment is done at’. Therefore all other variables must be kept
constant. I will do this thusly:
The surface area of the beetroot cylinder : I will keep this constant
by using the same cork borer for all the cylinders and measuring their
lengths with a ruler to ensure they too are the same length (4.
3. The time taken for the yeast to heat up to the temperature of the
Considering the fact that Marc has both been sweating and drinking minimal amounts of water, Marc is now dehydrated. This means he has less than the required amount of water for his body to complete the processes necessary to maintain its health. As stated in the question, the process of sweating causes the loss of more water than solutes. This means that as the level of water decreases, the level of solute concentration will increase, creating a change in the water to solute ratio.
The data we gathered was tested to be as accurate as possible. Our prediction on the solvents did not support our data that we collected. The cause of this could be due to human error when washing the beets or the cutting of the beets. The beets were not perfectly cut the same size, so some beet pieces were bigger than others which can affect the final the final result. We followed each step and followed the time limits cautiously. I can say if we were to redo the experiment our results would be similar because we would attempt to do the experiment as close as we did the first
Method: [IMAGE] Equipment needed: Ruler Measuring Cylinder Scalpel Tongs Pipette Thermometer Tri-pod Stop-clock Gauze Delivery Tube Bunsen Burner Beaker Matches/Lighter Potato Hydrogen Peroxide Solution (20%) Water Lead Nitrate The skin of the potato was removed using a scalpel and then cut into 1cm², using a ruler to measure the size of each cube, four cubes are required for each experiment, and therefore at least 36 cubes are required for the full experiment to take place. Fill a beaker half way with water, and place a thermometer in the water. Allow the thermometer to warm to room temperature to gather an accurate reading, and measure the temperature, using the thermometer. A measuring cylinder was used to put 10ml of Hydrogen Peroxide Solution into a
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.
Osmosis Experiment Planning Aim: The main subject that I will be planning to investigate is the effects of a concentrated sucrose solution on potato cells on the basis of the Osmosis theory. Background knowledge: The plant cell and its structure To understand osmosis in detail I will need to explain the plant cell (which is the cell included in the osmosis experiment) and its cell membrane. Below I have a diagram of a plant cell: [IMAGE] Osmosis is about the movement of particles from a higher concentrated solution to a lower concentrated solution to create an ethical balance via a partially or semi permeable cell membrane. Osmosis in simple terms is the exchange of particles between the cytoplasm inside the cell and the solution outside the cell. What makes this exhange is the partially permable cell membrane.
* We would have to leave one end open to fill it up with the different
The purpose of this experiment is to investigate the effect of changing the concentration of sodium chloride solution on the rate of osmosis in tubes of potatoes. This was maintained using equal measurements of the potato tubes and applying them into the different concentrations of sodium chloride, 0%, 2%, 5%, 10%, 20% and 26%, in beakers then measuring the change in mass of the potato tubes afterwards. The time taken for all potato tubes to be placed in solution was 15 minutes. Can the concentration gradient of the sodium chloride solution influence on the rate of osmotic diffusion undergone by the potato tubes?
The experiment is aimed at giving a better understatement of osmosis process and the different conditions in which osmosis occurs.
As soon as the sample of beetroot is placed into the distilled water diffusion occurs naturally, which is the net movement of molecules. from a region of high concentration (beetroot sample) to a region of low concentration (beetroot sample low concentration (distilled water). From 40°C upwards there is a sudden increase in absorbency, this is. because the optimum temperature at which enzymes and cells can work at is 37°C and as soon as you go above this temperature it will cause the enzymes and cells to denature and cease from working effectively. Even if you then lower the temperature again the cell will not regain.
The effect of temperature on the beetroot membranes Aim of the research: The aim of this investigation is to determine what kind of effect will the increasing temperature have on the plasma membrane of a beetroot cell. Introduction The beetroot contains a red pigment that is kept in the cells by the membranes. If the membranes are damaged, the pigment “betalain” will leek out. The amount of pigment that leeks out can be assessed, as “betalain” will colour any water that surrounds the cell.
- The nurse’s mistake will increase the saltiness due to the double amount of saline in the bag.
We then put the stopwatch on and left them for half an hour. After we weighed each potato tube and recorded our results. We did the experiment twice. We did this to make sure our results were correct. Preliminary method: We did everything the same as in our other experiment except we
· The beetroot piece is then placed into a tube of 5 cm of distilled
Equipment Potato, Borer, Beakers, Measuring Cylinder, Stopclocks, Distilled Water, Electronic Balance, Salt solutions of various concentrations. Diagram [IMAGE] [IMAGE] [IMAGE] When we leave the potato in the solution for the allocated time, water