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

water potential of potato tuber cells

Extracts from this document...

Introduction

DAVOR ZIBAR WATER POTENTIAL OF POTATO TUBER CELLS INTRODUCTION: AIM: To find the water potential of potato tuber cells. HYPOTHESIS: When cells are put in a solution with a different water potential than inside of them, cells will gain or loose water. If concentration of solution is the same, there will be no change in mass. THEORETICAL BACKGROUND: If a sample of tissues immersed in solution of varying water potential (concentration of water molecules), the cells will loose or gain water by osmosis. If the cell is put into solution of higher water potential (hypotonic solution), water will go inside the cell. As the pressure potential rises inside the cell it becomes turgid. In the plant cells turgidity is rising up the moment when cell can't take more water because of cell wall. Animal cells don't have cell wall so water is constantly going inside the cell until it lyses. If the cell is put into solution of lower water potential (hypertonic solution) the water will go out of cell and cell will be plasmolysed. In both ways cell will gain or loose mass. APPARATUS AND MATERIALS: * Cork borer * Scalpel * Syringe * Digital balance * Filter paper * Forceps * Blue ink EXPERIMENT 1: METHOD: 1. ...read more.

Middle

Digital balance has smaller uncertainty than analog ones so it is better to use. LIST OF VARIABLES AND THEIR CONTROL: * Time: all times are used accurately and measured with stop watch * Potato size: accurate measurements * Volume of solutions: accurate measurements * Ph: use distilled water * Same potato: different potato may have different water potentials RELIABILITY OF VARIABLES: Same potato has to be used because different potato may have different water potential so results wouldn't be reliable. Tap water is ionised so water potential can't be 0 so distilled water is used because it doesn't have any ions in it. Also Ph of distilled water is neutral so there is no change in permeability of membrane. SAFETY: * Carefully use cork borer and scalpel to prevent injuries by cutting * Watch out that you don't break any glass apparatus to prevent cutting RESULTS: EXPERIMENT 2 SUCROSE SOLUTION AFTER POTATO WAS TAKEN OUT mol dm3 CHANGE IN HIGHT OF COLOURED SOLUTION 0.1 SINKING 0.15 RISING 0.2 SINKING 0.25 RISING 0.3 RISING 0.5 RISING 1 RISING ANALYSIS: When potato was immersed in solution it gained or lost water. Sinking in this table means that potato gained water so coloured solution had bigger density and it fell on the bottom of test tube when it was immersed in the solution no1. ...read more.

Conclusion

Experiment 1 is more reliable because electronic gear was used which has less uncertainty than human eye and skill in experiment 2. Errors appeared because of human errors. * There was problem to cut same cylinders of potato because any difference in length can affect the result. * Making appropriate solutions was easy but there is also some kind of uncertainty in them because we are never sure that exactly correct solution is made. * There is potential error in weighting the potato after it stayed in solutions for 24 hours. If the potato hasn't been dried when it was weighted, mass of water also affects the result because masses are small and measured in grams with numbers smaller than 0. * The trickiest part of experiment 2 was to put the drop of coloured solution in other without dispersing it. In my attempts to put it in the solution I had little success. I squeezed the syringe too hard and drop just popped out of it causing the current in the solution so I couldn't see if colour was sinking or rising. That's why experiment 2 hasn't been successful. The best reliability for experiment would be to repeat it and to take average of solutions. For experiment 2, repetition is also needed so I would improve my skill of immersing a drop into other solution without dispersing it. ...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 determine the water potential of a potato tuber cell using varying salt solution.

    5 star(s)

    as more water will be entering the cell and I believe that the cell will then swell and become turgid because the water potential outside the cell is more then inside the cell therefore water will enter the cell as the theory of osmosis states water molecules from a region

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

    1 To measure the solution and distilled water accurately Syringe (20cm�) 1 To measure the solution and distilled water accurately Stopwatch 1 To time how long the tubers are submerged in the solution. Tweezers 1 To remove the potato cylinder from the boiling tube Digital weighing scales 1 To weigh

  1. The determination of the Water Potential of Potato Tuber Cells

    I would also perform the experiment in a temperature and light intensity controlled room, this would prevent changes in both of these. These changes could cause the cell work rate to rise or drop also it could cause the water and sucrose molecules to speed up movement which could effect the rate at which osmosis takes.

  2. Water potential of potato tuber cells - the weighing method.

    Solute Potential Potential So by using the method of incipient plasmolysis we are also working out the solute potential of the solution, as it is equal to ?cell. Water potential of potato tuber cells - the weighing method Method 1)

  1. Investigating the cellular water potential of potato cells.

    The plasma membrane mainly consists of phospholipids. These phospholipids are a phosphate head, which is attached to two fatty acid tails (hydrocarbon chain). The phosphate group is highly soluble in water and so hydrophilic; however, the fatty acid tails are not soluble in water and therefore are hydrophobic.

  2. An Investigation to determine the Water potential of Potato cells.

    20 Austen denied shayon's realism . 0.35 This essay from www.coursework.info 12coba bar sebabaw orba bak inba foba ba; 8cogb gbr segbgbw orgb gbk ingb fogb gb! 20 This work from www.coursework.info 0.40 shayon, please do not redistribute this essay. We work very hard to create this website, and we trust our visitors to respect it for the good of other students.

  1. To determine the water potential of potato tuber tissue

    Prediction My pilot study results give me a base for a prediction, as they give values for the mass loss in various solute potentials. This means, I already can see a trend forming for my experiment. This is, in short, a water potential of potato tuber tissue around 0.3M sucrose

  2. An Investigation to Determine the Water Potential of a potato tuber

    This is called the isotonic point (at which water neither leaves nor does it enter the cell). This however is not the case for plant cells. Although the plant cell will change in mass according to whether it gains water or loses water, its shape is kept the same.

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