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

An investigation into the osmotic properties of a kumara (sweet potato)

Extracts from this document...

Introduction

An investigation into the osmotic properties of a kumara (sweet potato) Aim The aim of my experiment is to find the water potential of the kumara or sweet potato by investigating the osmotic properties and hence come to a conclusion of the exact water potential. 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. Semi-permeable membranes are very thin layers of material (cell membranes are semi-permeable) which allow some things to pass through them but prevent other things from passing through. These things pass through tiny pores in the semi-permeable membrane. Cell membranes will allow small molecules like oxygen, water, carbon dioxide, ammonia, glucose, amino-acids, etc. to pass through. Cell membranes will not allow larger molecules like sucrose, starch, protein, etc. to pass through. Cells walls found in plant cells are fully permeable. A region of high concentration of water is either a very dilute solution of something like sucrose or pure water. A region of low concentration of water is a concentrated solution of something like sucrose. ...read more.

Middle

If you put plant cells into concentrated sugar solutions and look at them under a microscope you would see that the contents of the cells have shrunk and pulled away from the cell wall: they are said to be plasmolysed. When plant cells are placed in a solution which has exactly the same osmotic strength as the cells they are in a state between turgidity and flaccidity. We call this incipient plasmolysis. "Incipient" means "about to be". When I forget to water the potted plants in my study you will see their leaves droop. Although their cells are not plasmolsysed, they are not turgid and so they do not hold the leaves up into the sunlight. Apparatus: * McCartney bottles * Stopwatch * Scalpel * Cork borer * Sucrose solution 2Molar concentration * Kumara (sweet potato) * Filter paper * Weighing scales * Syringe Variables The variables in this experiment are: size, temperature, volume of solution, surface area of kumara, concentration, maturity of kumara and pressure. The variable I will change is the concentration of the sucrose solution. Results Before (g) ...read more.

Conclusion

I cannot see an anomaly, this is most probably as the experiment was comprised of 3 sub experiments giving a fair and accurate average. An anomaly could also have been the result of the Kumara being changed at that point so the molar of sucrose in the new Kumara could have been different. The results give enough evidence to let me conclude that the Kumara gains weight in low molar sucrose solution because I know that that the kumara has a high sugar content and that using osmosis the water in the sucrose solution will diffuse from an area of high concentration to an area of low concentration. To improve the experiment I could try to do the whole experiment with the same kumara and weigh them more accurately. To further the investigation I could use potatoes or another fruit and compare those results to that of the Kumara and in doing so find out which has the highest sugar content and water potential. ?? ?? ?? ?? William Biggs Biology coursework Investigating the osmotic properties off a kumara ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Exchange, Transport & Reproduction 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 AS and A Level Exchange, Transport & Reproduction essays

  1. Marked by a teacher

    Investigate the water potential of celeriac.

    5 star(s)

    This is where the gradient of the graph suddenly becomes a lot steeper; therefore, the average percentage change in mass is greater than at sections A and B. The celeriac cells start to lose more mass at section C. During section D, the gradient of the graph becomes flatter; therefore

  2. Marked by a teacher

    Osmosis. Aim: To find the molarity of potato tubers cell sap. BIOLOGICAL ...

    4 star(s)

    Firstly, I had to prepare the 1 molar solution. I cut out 8 strips of potato using a cork borer and made them of the same length of 3 cm. I then measured their mass and noted them down. Then I washed and dried the Petri dishes. I poured out the solutions into two Petri dishes and labelled them.

  1. Marked by a teacher

    Determining the Water Potential of Sweet Potato Tissue

    4 star(s)

    If a solution is separated from pure water by a partially permeable membrane, the pressure that must be applied to prevent osmosis is called osmotic pressure. Osmoregulation is the ability of an organism to regulate its water potential. For example, if a cell is placed in a solution with higher

  2. Marked by a teacher

    Effect of temperature on membranes

    3 star(s)

    shape with a cylinder stalk on the top of it and is available in many varieties. Beetroot provides a rich source of carbohydrates, protein, and has high levels of important vitamins, minerals and micronutrients. Beetroot is also a great source of, magnesium, potassium, iron folic, acid, zinc, calcium, phosphorus, sodium, niacin, biotin, betanin and beta-carotene.

  1. Peer reviewed

    The comparison of antibacterial properties of herbal products and standard antibiotics

    5 star(s)

    Due to their simplistic nature, they are also very small an inhibit places such as water, air and human bodies. The majority of bacteria are harmless, however various bacteria that inhibit the body are known as pathogens and can cause disease and infection.

  2. To find out the factors affecting the refractive index of liquid by using different ...

    Even if I raised the temperature, the molecule moved faster but they are still moving around randomly. The speed of light only change very little with increasing temperature. The design of the experiment should be more precise in order to detect that little change.

  1. Investigation on Osmosis using a potato.

    So we have decided to put the potatoes in first then the solutions. To avoid any confusion the test tubes will all be labelled first. When using the balance, we will make sure that the balance is reading zero, before we put the 3 potatoes on it.

  2. Investigating osmosis on swede cells.

    * Cork borer- to extract swede which will have the same diameter * Ceramic tile- To cut the swede safely into 3cm long pieces * Ruler- To measure the swede before and after being immersed in solution * Top pan balance- To weigh the swede before and after being immersed

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