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

My main aim in this experiment is to find out if osmosis occurs in a potato, and how it affects the potato in different molar solutions of sucrose and water.

Extracts from this document...

Introduction

PASSIVE PROCESSES Aim My main aim in this experiment is to find out if osmosis occurs in a potato, and how it affect the potato in different molar solutions of sucrose and water. Planning Before actually planning the experiment, I will do some research to find out about osmosis, and matters related to it, so that I can make predictions. And figure out a way to make this investigation fair and safe. Planning ahead would help me find out how to do what, when, which should lead me to good results at the end of the experiment. Osmosis The movement of water molecules across a partially permeable membrane from a region of high water concentration to a region of low water concentration. In a higher concentration of water there is a lower solute being called a weak or dilute solution and a low concentration of water is a higher solute being called a strong or concentrated. In a semi permeable membrane water divides to two solutions from high to low until both are equal. This water will move across the semi permeable into cells where there is lower water concentration by osmosis, this makes cells swell (turgid). Hypothesis Osmosis is the passage of water molecules from a weaker solution into a stronger solution, through a partially permeable membrane. In this case, the tiny holes in the membrane of the potatoes will allow the water molecules to pass through in and out of the solution and the potato, depending on the concentration gradient of the two substances. ...read more.

Middle

If the volume of one solution in a test tube is higher or lower than another, will affect the pattern of results later on. We will also make sure that the potato is fully covered by the 6 different kinds of solutions. This is because, is the potato isn�t covered up by the solutions, the effect of osmosis might not occur to the fullest. Small things such as a dirty test tube, and a slightly cracked measuring cylinder could still affect the results, and therefore we will take these into account as well. Variables The several different factors that affect the rate of osmosis: Potato tissue: The number of cells that make up the tissue also help in the taking in or out of the water from or to the semi-permeable membrane increasing or decreasing the process. Potato mass: The more the weight of the potato the more likely for the tissue to have more cells passively working on the process. Water volume: The more or less water means a dilute or concentrated solution which increases or decreases the diffusion of water. Sucrose solution : The molarity of sucrose in the solution means the solution is either high or low water concentrated so controlling the amount of water diffising in or out of the cell. * These are classified under three types of variables. Fixed variables : these are factors I will keep the same in the experiment for a fair test: a) Length of potato b) ...read more.

Conclusion

Percentage (%) 0.0 1 5.87 5.89 0.02 0.41 2 5.81 5.84 0.03 0.62 3 5.85 5.88 0.03 0.62 Average A 5.84 5.87 0.03 0.55 0.2 1 5.85 5.85 0.00 0.00 2 5.83 5.83 0.00 0.00 3 5.84 5.84 0.00 0.00 Average A 5.84 5.84 0.00 0.00 0.4 1 5.87 5.69 -0.18 -3.70 2 5.66 5.51 -0.15 -3.22 3 5.74 5.62 -0.12 -2.53 Average A 5.76 5.61 -0.15 -3.15 0.6 1 5.87 5.63 -0.24 -4.93 2 5.86 5.57 -0.29 -5.97 3 5.88 5.55 -0.33 -6.76 Average A 5.87 5.58 -0.29 -5.89 0.8 1 5.81 5.49 -0.32 -6.65 2 5.62 5.22 -0.40 -8.66 3 5.86 5.53 -0.33 -6.79 Average A 5.76 5.41 -0.35 -7.35 Analysis of table The table above shows that the more sucroce in the solution the less the weight of potato after bieng put in the solution. As osmosis Is diffusion of water from a high to a low concentrated region the concentrated solution will have a low water concentration so water will diffuse into it making the potato swell but the dilute solution will be high in water concentration so water will diffuse from the potato to the solution making the potato shrink. From the table we obtained decreases or increases in percentage and the potatos that had decreased or increased were classified under the three variation contents in solutions which are: * Hypotonic: The solution with the lower concentration of solutes e.g 0.0M * Hypertonic: The solution with the higher concentration of solutes e.g 0.4M, 0.6M, 0.8M * Isotonic: The solutions being compared have equal concentration of solutes e.g 0.2M From the variation contents in solutions the cells changed and I classified the changes under the three types of plant cells: ...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

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 GCSE Life Processes & Cells essays

  1. Marked by a teacher

    To investigate how varying the concentration of sucrose solutions affects the rate of osmosis ...

    3 star(s)

    The diagram below shows what I think must have happened to the potato cells after I had immersed the potato cylinders in distilled water and sucrose solution: Planning my actual experiment: When I conduct my actual experiment, I will use the same procedure as that of my prior test.

  2. Osmosis. My main aim in this experiment is to find out if osmosis occurs ...

    The smaller the concentration of water in the external solution the greater the amount of water that leaves the cell. However, there will be a point where the concentrations of water inside and outside the potato cells are equal (isotonic).

  1. Osmosis in potatoes at different concentrations of sucrose solutions.

    What happens is that they become turgid from being in a dilute solution as the pressure inside the cell increases or become plasmolyzed in a concentrated solution as the pressure inside the cell decreases because of having being in a more concentrated solution.

  2. Osmosis is defined as 'the movement of water molecules from an area of high ...

    left in the solution must be kept the same in each experiment. This is because more or less solution may be absorbed depending on time. I am going to keep each potato chip in each solution for 10 minutes, in a boiling tube.

  1. Osmosis in Potato's

    We will be measuring them before immersing them in the solution and after taking them out of the solution. Equipment used: * Sugar solution of 2M * Water * Cork borer - size 6 * A ruler cm/mm * 3 pieces of potato * Timer * Measuring cylinder * White

  2. An Experiment to Find Out How the Concentration affects osmosis

    amount of water, mass lost from the pieces of potato will increase. At 100%, the amount of mass lost by the potato will be more than at all of the other percentages. I also predict that in the pure water the potato the potato will gain in mass.

  1. Looking at how concentration affects the movement of water particles through a partially permeable ...

    the presence of cyanide, will cause active transport to slow or stop altogether. Cell can take up some particles and keep them in high concentration. Sometimes cells can keep hold of particles and not let them diffuse out. What's more they can even take in more particles against a concentration gradient.

  2. Osmosis, My aim for this experiment is to see the results of potato tissue's ...

    4: Accurate amount of sugar solution: More Bathing solution may affect the rate of solution. To make the amount of solution placed in the test tube as accurate as possible a perpet will be used to measure out the exact amount needed.

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