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

Osmosis Coursework

Extracts from this document...

Introduction

Osmosis Coursework Explanation on Osmosis and diffusion: "Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration, which will then become equal." Diffusion, although at first may seem insignificant in nature, plays quite a major part. The most obvious example would be in cells, plant and animal alike. They have partially permeable membrane in order to let in things like water, and to prevent unwanted big chemicals such as sucrose from entering. However, diffusion only takes places where there is a diffusion gradient i.e. a high concentration in one place and low in the other, moving down the diffusion gradient. Sometimes there are things which have to work against diffusion e.g. plants who need to absorb mineral ions from the soil, even though the concentration of ions is much higher in the plant that in the soil. The process of absorbing these minerals is called Active Transport. Hypothesis: I think that, as the concentration increases so will the mass of the potato. This is due to osmosis. I believe that because there will be a higher water concentration in the solution than in the potato then water will enter the potato to make the concentrations both inside and outside the potato equal. Theory: In this experiment we will look at the rate of osmosis on pieces of potato. ...read more.

Middle

Doing this preliminary work helped me make my hypothesis. It gave me a clear understanding of the process and therefore can give man idea of the rate of osmosis in a certain amount of time and different sucrose concentrations. Variables ? Mass of potatoes ~ the mass is very important because the bigger and heavier the potato chip, the longer it will take osmosis to occur. If the size of the potato chip varies, so will the amount of mass it loses or gains. The potato chip will be measured before it is put in solution, and after it has been taken out. This will let me see how much osmosis has taken place. ? Concentration of sucrose solution ~ the stronger the solution, the quicker osmosis occurs. More osmosis will occur out of the chip. Because I am investigating different sucrose concentrations, I am going to put the potato chips in different concentrations. These concentrations will be: 0.2m, 0.4m, 0.6m, 0.8m, and 1m. ? Time ~ the longer you have the potato chips in solution, the better, because more osmosis can occur. If you take the chips out after a few minutes, nothing is likely to have happened. This is why the time is important. More or less solution gets absorbed depending on the time. ? Room temperature ~ the colder it is, the longer it will take osmosis to occur. ...read more.

Conclusion

Table Of Results 1.0(sucrose concentration) Average % Change Mass Before 3.01,2.98,3.01 3 -27.7 Mass After 2.21,2.13,2.17 2.17 0.8(sucrose concentration) Average % Change Mass Before 2.99,2.93,2.97 2.96 -19.93 Mass After 2.31,2.39,2.40 2.37 0.6(sucrose concentration) Average % Change Mass Before 3.01, 3.05, 3.04 3.03 -15.73 Mass After 2.52, 2.55, 2.57 2.55 0.4(sucrose concentration) Average % Change Mass Before 3.04, 3.02, 3.10 3.05 -5.57 Mass After 2.86, 2.88, 2.90 2.88 0.2(sucrose concentration) Average % Change Mass Before 3.04, 2.92, 2.97 2.97 3.43 Mass After 3.10, 3.07, 3.04 3.01 As I expected. There was a greater percentage mass change as the concentration increased. This shows my prediction was correct. Conclusion I have found from my repeated results, that my prediction was correct. As the sucrose concentration rose the potato lost weight. Alternatively, as the water concentration increased the potato gained weight. This shows that osmosis happened. For example in the case of 100% sucrose solution: 1. There was more sucrose (low water concentration) outside the potato than in it. There was more water in the potato (high water concentration). 2. Water left the potato and passed through the semi-permeable potato cell membranes. 3. The levels of water concentration were then equal both inside and outside the potato 4. The weight of the potato decreased when water left it. For example, when we had an increasing concentration of water, the low water concentration solution diffused into the potato, this balanced the water concentrations inside and outside the potato. ...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

3 star(s)

This is a good report that has a clear structure and uses research to guide the process.
1. The introduction and background knowledge sections are well researched but this information needs to be referenced and rewritten.
2. The variables section contains a good level of detail.
3. The preliminary work is a good lead in to the investigation.
4. The results table needs to be readdressed.
5. The conclusion shows a good understanding but lacks structure and evidence.
6. There is no evaluation.
*** (3 stars)

Marked by teacher Luke Smithen 29/05/2013

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

See related essaysSee related essays

Related GCSE Life Processes & Cells essays

  1. Marked by a teacher

    Biology Coursework - Osmosis

    5 star(s)

    is arguably, one of the most important processes in all of nature. Plan: Potato Cell Research I also did some research into potato cells, and the effect of osmosis upon them. Here's what I found: Potato tuber cells, are plant cells, they feature many of the characteristics of the stereotypical

  2. Marked by a teacher

    Isotonic Point of Potatoes

    5 star(s)

    Thus there is an inverse relationship between the concentration of the solution and the percentage increase in the mass of the potato cells - as the solution becomes more concentrated, the percentage increase in the mass of the potato significantly decreases as there is a change from net movement of

  1. Marked by a teacher

    "Osmosis" - The Potato Experiment.

    4 star(s)

    This rough table shows the values I collected after the experiment Test Tube Concentration of Sodium Chloride solution /moles Mass Before /g Marked Unmarked Mass After /g Marked Unmarked Percentage Increase/Decrease Marked Unmarked 1 0.0 2 0.2 3 0.4 4 0.6 5 0.8 6 1.0 These are the final results showing the percentage increases and decreases for each potato cylinder.

  2. Aim To determine the water potential of a potato tuber cell

    In general although there may have been many potential and definite errors within this investigation, my prediction was proved to be right and graph showed my results to be accurate and reliable highlighting that my method was simple to follow showing that this investigate was quite a success.

  1. An experiment to investigate the effects of sucrose solution on Osmosis in potatoes chips.

    This analogy is as the sucrose concentration increases. The graph does not support all of my original predictions that I stated in the planning. Evaluation: In my opinion the experiment was not a total success. This is because of an error in the 0.2m solution.

  2. Does the concentration of sugar levels affect osmosis in potato plants?

    But other wise my method is simple and detailed and also importantly easy to follow. To extend my experiment to get more evidence for my conclusion I could always repeat the experiment over and over again this would allow me to collect more accurate more convincing results.

  1. Investigating the effect of changing the concentration of an acid on the rate of ...

    Dilution Table I used this table to make the other concentrations of HCl (other than 1.0moldm-3), using the 1.0moldm-3 acid. Conc. Of HCl (moldm-3) Acid (cm3) Percentage Water (cm3) Percentage 0.2 1 20% 4 80% 0.4 2 40% 3 60% 0.6 3 60% 2 40% 0.8 4 80% 1 20%

  2. To investigate the effect of different concentration of sucrose on osmosis in potato chips

    Again we could do more concentrations, to resolve this problem and get more accurate data. This is again because, more concentrations would mean narrowing the concentration intervals down, and a more accurate plot of results on the graph. This would more likely give us a more accurate interpretation of where the concentration inside and outside the potato is equal, i.e.

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