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

# Water potential of a potato

Extracts from this document...

Introduction

Biology Coursework For this coursework I am going to be investigating the water potential of a potato. I will now go over the relevant scientific processes which are going to take place during this investigation. Firstly, 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. The movement of water in plant cells is controlled by this process. fig.cox.miami.edu The factor determining how much water will move from the potato is decided by the water pressure of the solution. Water potential is measured in KPA - Kilo Pascal's of pressure. Pure water has a water potential of 0. Here is a diagram of a potato cell. The starch grains found in the cytoplasm allows water potential to stay higher because starch is insoluble and want mix to make a solution. The middle of the cell contains the cell sap. http://www.uq.edu.au/_School_Science_Lessons/2.0CellPotato.GIF There are two terms used toward the structure of a plant cell. They can become either Turgid or Flaccid. Flaccid occurs during plasmolysis where there is a low water content and minimal outward pressure on the cell wall. ...read more.

Middle

+ ( 22x11) (11x16) = 342 so therefore is 342g of sucrose in 1000cm3 of water. From sucrose I would need to work out the how many grams in 1000cm3. Of course this is to high to work with so by dividing both the Sucrose weight and cm3 of water by 5 I received and more workable amounts of 68.4 g of sucrose is 1 mole in 200cm3 of water. The apparatus I used to for included: * Sucrose * Test Tubes * Beaker * Distilled water * Potato's * Electronic balance 0 Mol 0.5 Mol 1Mol Cells: 40 40 31 Plasmolysised: 0 5 19 % Polymolysised 0 % 12.5 % 61 % Using the information I have gathered here it would appear that the equilibrium is somewhere between 0.5 Mole's and 1 Mol. I do not believe it is entirely accurate to measure the plasmolysis this way so I have left the opened the next investigation from 0.25 - 0.75. I have also decided that I am going to measure mass change rather than count plasmolysised cells as I believe this will be more accurate. ...read more.

Conclusion

into the potato cell due to osmosis making the potatoes cells to become turgid and causing and increase in potato mass Here is the diagram I used before. Here it shows what happens when the sucrose solution concentration is above the 0.27Mol of the potato cell chip and vise versa if the solution is lower. Here is the other diagram from before this is now relevant in that it show that at the point of equilibrium (0.25Mol) in this case. There is equal movement of water between the cell tissue and solution as there is nothing to be balanced out . As you can see from the graph showing the kPa of the different sucrose concentrations 0.27 Mol dm-3 equals 720 kPa This means that the potato chip has water potetinal 720kpa. The potato chip could potentials have a higher water potential but it contains starch molecules within the cells. This starch molecules are insoluble, if they were soluble they would mix with the water and the water potential would be increased and the cells could burst from the increased in turgor pressure within the potato cell The starch molecules can be identified in this diagram I used before ...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

# Related GCSE Life Processes & Cells essays

1. ## Investigate the water potential of potato tissue and compare this with the water potential ...

Again, record which number sample is going in which concentration of solution. 5. Place the 24 sets of pairs in the Petri dishes (i.e. two to a dish.) 6. Write which replicate is which next to the Petri dishes. 7.

2. ## Osmotic pressure

and the cube of potato that was in the distilled water became hard, firm and larger (turgid). b) Analysis: Osmosis is the reason that the potato cubes changed in texture when put in different solutions of water. The definition of osmosis is the movement of water through a semi permeable

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

There were also other things, like having the chips 5cm long. I changed this to 3cm because I couldn�t find 10 5cm long chips. Also, I changed the amount of solution I would keep the potato chips in, because otherwise the water spilled out of the tube, and I only needed enough to cover the chip (it was 100ml).

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

-5.61 TY1zxHo Visit coursework eb in eb fo eb for eb more paper eb Do eb not eb redistribute TY1zxHo 8.41cofb fbr sefbfbw orfb fbk infb fofb fb. The information gained from this preliminary experiment helped me to plan an appropriate strategy to obtain the most suitable results to achieve my aim in the following ways.

1. ## Investigating the cellular water potential of potato cells.

In this experiment we have to determine the water potential of potato tissue. Water potential equals to solute potential because pressure potential is zero. This is because there is no pressure added or taken away in this experiment; pressure does not vary in this experiment as we are leaving it natural.

2. ## The endeavour of this investigation is to ascertain if there is any effect of ...

The results showed that equilibrium was between 0.25 Results from preliminary experiment Molarity: No. of cells showing incipient plasmolysis: Result: 0.00M 0 turgidity 0.25M 4 turgidity 0.40M 60 near equilibrium 0.50M 20 plasmolysis 0.80M 5 plasmolysis Evaluation: This investigation was not totally reliable because it was prone to inaccuracies due to human in capabilities.

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