• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Biology Lab Report-Osmosis

Extracts from this document...

Introduction

Shreya Shah IBD Year 11 Biology Lab Report: Osmosis Title: Osmosis in a potato chip. Aim: To investigate the effect of varying concentration of a certain sugar solution on the amount of osmotic activity between the solution and a potato chip of a given size. Hypothesis: The potato chips left in diluted solutions will increase in size, with the one kept in the solution of maximum dilution increasing in size the most. While the potato chips left in the concentrated solutions will decrease in size, with the one kept in the solution with the highest concentration decreasing in size the most. Osmosis is the movement of solvent molecules from their region of higher concentration to their region of lower concentration through a semi-permeable membrane, i.e. the molecules move down their concentration gradient. The process continues until the solutions on both sides of the semi- permeable membrane are of the same concentration. The potato chip cells and all the solutions used in the experiment each have their own concentration. Some solutions may have a higher concentration (lower osmotic potential) than the potato chip cells, while some will be at a lower concentration (higher osmotic potential) than the potato cells. This creates a concentration gradient. ...read more.

Middle

0.1M NaCl 3.21 3.35 44.0 44.0* 3. 0.2M NaCl 3.53 3.60 45.0 43.0 4. 0.3M NaCl 3.51 2.92 43.0 40.0 5. 0.4M NaCl 3.37 2.52 45.0 40.0 * This result appears to be anomalous Table 3: Percentage change in mass and length of potato chips in Trail 1:- Solution Calculations [(end mass - start mass) � start mass] x100 Percentage change in mass (in %) Calculations [(end length - start length) � start length] x100 Percentage change in length (in %) Distilled water [(2.92 - 2.51) � 2.51] x100 = 16.3 [(47.0 - 43.0) � 43.0] x100 = 9.30 0.1M NaCl [(3.35 - 3.21) � 3.21] x100 = 4.36 [(44.0 - 44.0) � 44.0] x100 = 0.00* 0.2M NaCl [(3.60 - 3.53) � 3.53] x100 = 1.98 [(43.0 - 45.0) � 45.0] x100 = -4.44 0.3M NaCl [(2.92 - 3.51) � 3.51] x100 = -16.8 [(40.0 - 43.0) � 43.0] x100 = -6.98 0.4M NaCl [(2.52 - 3.37) � 3.37] x100 = -25.2 [(40.0 - 45.0) � 45.0] x100 = -11.1 *This result appears to be anomalous Table 4: Results for Trial 2:- Solution Mass of chip- (in g �0.01g) Percentage change in mass (in %) Length of chip- (in mm �0.5mm) ...read more.

Conclusion

no change Slightly turgid Very slightly Hypo-osmotic 0.2M NaCl Increase Decrease Flaccid/ Plasmolysed Hyper-osmotic 0.3M NaCl Decrease Decrease Flaccid/ Plasmolysed Hyper-osmotic 0.4M NaCl Decrease Decrease Flaccid/ Plasmolysed Hyper-osmotic Thus, from Table 6 we can assume that the concentration of the solution in the cell is somewhere between 0.1M and 0.2M Evaluation: Despite taking several measures to prevent errors from occurring, a certain number of errors are unavoidable. These are mainly random errors which are caused by mistakes made while handling or reading equipment. These are probably the main reasons for the anomalies which have been discussed Special care was taken to ensure that the experiment was a fair test. All the chips were cut from the same potato, therefore eliminating any differences in absorbency. The flexibility of chips was tested after they had been weighed and measured so that it would not matter if pieces of the chips broke off since they had already been weighed and measured. To improve this experiment a wider range of concentrated solutions could be used to produce more varied results that would highlight, more clearly and accurately, the concentration of the solution inside potato cells. Overall, this experiment was quite accurate and successful in investigating the process of osmosis and concluding that the concentration of solution inside a potato cell is somewhere between 0.1M and 0.2M. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

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

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

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Marked by a teacher

    Biology: Lab report Germination

    4 star(s)

    This can be collected from the graph because of the proximity of the red an green line, the lines sometimes overlap. Discussion Conclusion Light Experiment I will conclude each experiment separately as they were, in fact, separate experiments. Upon testing the variable of light, it has become apparent that seeds germinate more quickly in the light.

  2. Marked by a teacher

    IB BIOLOGY INTERNAL POTATO OSMOSIS

    3 star(s)

    Place a blue coloured pin in 5 potato chips, push the pins to the middle of the chips. 7) Repeat the previous process with 5 more chips using red pins. Then repeat again with 5 more potato chips using white pins.

  1. Osmosis Lab. Aim: To investigate the effects of different solute concentrations on osmosis, ...

    you can see the masses measured of the first days with its uncertainties of ?0.01g and its temperature of ?0.05?C.

  2. Potato IA Lab. This experiment tested osmosis when dealing with different concentrations of ...

    Weight After (g) Change (g) % Change Test 1 3.6g 2.3g -1.3g -36.1g% Test 2 3.6g 2.3g -1.3g -36.1g% Test 3 3.6g 2.3g -1.3g -36.1g% Test 4 3.6g 2.2g -1.4g -38.1% Test 5 3.6g 2.0g -1.6g -44.4% Average 3.6g 2.2g -1.4g -41.3% 1.0 M Salt Tests Weight Before (g)

  1. Biological Membrane Lab

    The size of the beet root squares could have been a bit inaccurate and might have included some ragged edges. There were few errors in the data as some of the squares of beet roots were punctured while stirring the alcohol solutions.

  2. Testing the solute concentration of potato cells

    In contrast, when potato piece has higher solute concentration, water molecules in sucrose solution move inside the potato, causing it to swell due to water uptake. Then, the potato would be longer and heavier. In short, to find out the solute concentration of potato cell, it is important to check

  1. Biology lab- osmotic pressure

    However if the sucrose solution is rather dilute with low solute concentration, then very little or no cells will undergo plasmolysis, but will instead turn turgid as water will enter these cells instead of leave them. Therefore the percentage of plasmolysed cells will increase with the concentration of the sucrose.

  2. Beet Lab. Aim: To determine the effects of temperature on the permeability of ...

    Before starting the experiment, we should just wipe the apparatus to ensure zero error. 7. Do not overtime the experiment. 8. When the beetroot was cut some of the membrane was broken causing the pigment to leak out this must be thoroughly cleaned and washed off to secure the accuracy of results.

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