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Biology Investigation - A fish and chip shop which specializes in French fry size chips.

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Biology Investigation A fish and chip shop which specializes in French fry size chips. The owner wants to chop up his chips the night before ready to be cooked the next day. To prevent them from drying up he puts them in a salty solution. The next day he finds the chips all shriveled up and gone soft What happened your task is to find out what h has to do with the salt solution to make the chips do not change appearance overnight. Prediction I predict that the chips In the chip shop shriveled up and went soft because of the salt solution he put the chips in. The amount of salt was more than the amount of starch in the chips. This happened because of osmosis. Osmosis is defined as the net of movement of water or any other solution's molecules from a region in which they are highly concentrated to a region in which they are less concentrated. This movement must take place across a semi permeable membrane, such as a cell wall, which lets smaller molecule such as water through, but does not allow bigger molecules to pass through. ...read more.


Turgid means swollen and hard. The pressure inside the cell rises and eventually the internal pressure of the cell is so high that no more water can enter the cell. This liquid works against osmosis. Turgidity is very important to plants because this is what make the green parts of the plant stand up into the sunlight. When plant cells are placed in concentrated salt solutions they lose water by osmosis and they become "flaccid." This is the exact opposite of "turgid". The contents of the potato cells shrinks and pulls away from the cell wall. Variables: To create a fair test certain aspects of the experiment will have to be kept the same whilst one key variable is changed. I have chosen to vary the concentration of the salt solution. This will give me a very varied set of results from which I hope to make a decent conclusion. If any of the non-variables below are not kept constant it would mean it would not be a fair test. ...read more.


Method Equipment Potato Scalpel Boiling tubes Salt water Water Measuring cylinder Test Tube rack Knife A range of salt solutions will be prepared with concentrations of 100%, 80%, 50%, 20%, 0% (pure water) salt solution. This will be done by adding varying amounts of distilled water to varying amounts of salt solution. Sections of potato will be cut using a scalpel and then weighed on an electric balance and recorded, the weight was made as close as possible on the two potato chips to be averaged. Two chips will be placed in each test tube each time so that I can take an average for each tube. I will use 50ml of each concentration of salt solution and once in test tubes each will be labeled. The potato pieces will then be placed in different test tubes and left for 30 minutes, I will time this using a stopwatch. Then the potato pieces will be removed, the surface solution removed using paper towels and then they will be reweighed. Results 2.16g 2g 2.485g 2.56g 2.665g The results I got are mainly accurate apart from one on 20% the second set of results the change is supposed to decrease instead of increase. ...read more.

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Here's what a teacher thought of this essay

**A reasonable start to a piece of coursework but unfortunately unfinished as there is no discussion of the results or evaluation of the method. This would need to be included to gain a good grade.

Marked by teacher Stevie Fleming 03/01/2013

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