• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5
6. 6
6
7. 7
7
8. 8
8

# Investigation into the effects of osmosis on Potato cells

Extracts from this document...

Introduction

Investigation into the effects of osmosis on Potato cells PLANNING AIM The aim of this investigation is to find out the concentration of cell sap in potato tissue. Variables * Controlled-Starting length will be as close to 3.00cm possible, starting volume, which is 20ml also the same time the potato cells are kept in solution and same conditions for each cylinder. * Dependant-Length of potato cylinder (before and after osmosis has occurred). * Independent-Concentrations of solutions which are: (m) 0,0.1,0.2,0.3,0.4,0.5 Solutions Vol. Of glucose * 0.5 = M (0.5 = starting glucose concentration) Total volume 1) 0 * 0.5 = 0 M 20 2) 4 *0.5 =0.1M 20 3) 8 *0.5 =0.2M 20 4) 12 *0.5 =0.3M 20 5) 16 *0.5 =0.4M 6) 20 *0.5 =0.5M 20 20 Prediction I predict that this experiment will have different results throughout all the concentrations. Osmosis depends on two concentrations; outside (glucose solution) and inside (cell sap). I feel that my experiment will prove that osmosis has occurred meaning the water has moved form a high concentration to a low concentration. But. If the cell was already turgid when we measured it, the movement of water from a higher concentration to a lower concentration means we will find the potato cell will shrink as the solution has moved out. ...read more.

Middle

Other instruments which were the measuring cylinders - 10 ml & 25ml that are accurate to *-0.1ml & *-0.5ml respectively. This helped when I had to measure out glucose solution and distilled water. This all helped to get accurate results & a successful experiment. Strategy for results For my results for the experiment, I will make a table with concentrations down the left side and lengths of potato cells along the top. Then the percentage change in length down the right side. The title will be - -Investigation into the effects of osmosis on potato cells: Results. The graph that I will plot my results will have Concentration of glucose (M) on the X-axis and % change in length on the Y-axis. On this I will draw a best-fit line. Above the X-axis, the results are Hypotonic and below the X-axis the results are Hypertonic. But if the results are on the X-axis line, the result is isotonic meaning the concentration inside equals' concentration outside. Table and graph overleaf To find the percentage change in length, I had to use the following formula: final length - original length original length * 100 (1) 0M; 3.12 - 2.96 2.96 * 100 = 5.405% (2) 0.1M; 3.14 - 2.98 2.98 * 100 = 5.369% (3) ...read more.

Conclusion

This might be anomalous because maybe the volumes measured inaccurately or the vernier callipers were read slightly wrong. This means if there was a mistake it was because of human error. How suitable was my procedure? I feel my procedure was well suited to this investigation, because 0.25M (isotonic) fell in between 0.2M and 0.3M, meaning a perfect experiment. Also the apparatus was good enough for a successful experiment. Any changes to improve? I fell that there are many changes I could do to improve my experiment to get more accurate results. And they are: 1. Be more accurate when cutting the cylinders, try to be as close to 3.00cm as possible. If we had two different starting lengths e.g. 3.02cm and 3.12cm it would not be fair because 3.03cm chip has a greater SA: VOL giving it an advantage in terms of osmosis. 2. A third potato cylinder could be cut and put into the specimen bottle to increase accuracy in getting results. 3. A burrette could be used. These are accurate to 0.1ml, which would help when we are measuring out our solutions. 4. Also Digital Vernier callipers would be useful as we could just read off the measurement and possibly eliminate human error when measuring. Does the evidence support a firm conclusion? Yes, because 0.25M (isotonic result) corresponds with book value so this is encouraging. Five of my plotted values follow the pattern and only one is anomalous. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Life Processes & Cells section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

## Here's what a teacher thought of this essay

5 star(s)

*****
This account shows attention to detail and good use of scientific language. There are a few minor errors.

Marked by teacher Adam Roberts 01/05/2013

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related GCSE Life Processes & Cells essays

1. ## Biology Coursework - Osmosis

5 star(s)

same variety treated in the same way, i.e.: have all been cut with scalpel, and skins removed. Temperature To ensure the temperature doesn't vary, I will perform all the experiments at room temperature.

2. ## Osmosis in Potato Chips

5 star(s)

is left in for 24 hours. This means that the water potential in the solution and the water potential in the potato chip must be the same at that time so osmosis would not happen. I propose that because osmosis is water molecules moving from a high concentration of water

1. ## Potato / Osmosis Experiment.

5 star(s)

Plasmolysis usually kills a plant cell because the cell membrane becomes damaged when it tears away from the cell wall. STAGE 3 is where the surrounding solution is isotonic to the cytoplasm of the potato sample's cells. Discovering this area on the actual graph, using a line of best fit, is the entire objective of the investigation.

2. ## What factors affect osmosis?

4 star(s)

As I have already mentioned earlier, the temperatures will be controlled so that the particles in the solution or water do not gain extra energy in comparison to the others and I will use the same balance to minimize the risk of incorrect readings.

1. ## See the effects of amylase on starch at different temperatures and to find at ...

I used a water bath to heat up the amylase and starch, each time for ten minutes at each temperature, I done this to make sure the temperature for each experiment was constant, for example it was 30�C for

2. ## To find out the internal concentration of a potato cell.

so these factors are controlled as the experiment will be done under the same conditions throughout, at room temperature. The surface area is controlled because more osmosis will be able to take place over a greater surface area. The potato cylinders will be cut out using the cork borer, and then cut to 4cm in length.

1. ## An experiment to investigate osmosis in plant tissue.

no air bubbles trapped in syringe as this will affect amounts of liquid in tubes. vii. Do not shout as it could disturb others concentration. viii. Most importantly be sensible. Conducting the Experiment i. Take the 12 potato chips from foil and cut single potato chip into a length of 2cm.

2. ## Find the concentration of Potato Cell Sap.

concentration of the cell sap must be equal to the concentration of that bathing solution. My line of best fit crosses the x-axis at 0.2 M Sucrose. Therefor, form my results, I can see that the concentration of the cell sap is 0.2 M Sucrose.

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to
improve your own work