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Movement in and out of cells

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Introduction

Movement in and out of cells Helen Moth The cell membranes main function is to serve as a boundary between the cell and it's environment. It is just like other organelles in the cell in that it serves the cell by having it's own specialised jobs. In terms of beetroot the purple pigment is contained within the cell membrane, if this membrane is disrupted the pigment will be released. Temperature may be the cause of the disruption. High temperatures could distort the "active site" of the carrier, channel of gated proteins, therefore affecting the shape of the fluid mosaic model membrane which may release molecules that normally would not be allowed to be released (in our case the purple pigment), or allow other molecules in. Temperature basically disrupts facilitated diffusion. The picture above shows a close up view of a cell membrane, cell membranes are made up of fat molecules, or to be more specific phospholipid molecules with various large intrinsic and extrinsic, globular proteins suspended in them. ...read more.

Middle

So in theory a low temperature will not affect the permeability of the cell membrane and therefore no or little purple pigment will be able to diffuse and detected by the colorimeter. However as the temperature increases the cell membrane will become more and more permeable because the heat will distort the protein shape and the cell membrane will allow more pigment to escape. The aim of this experiment is to see the effect of temperature on cell membrane permeability, to help me get accurate results, am going to choose the temperatures- 0�C- no pigment should be released because at very cold temperatures the cell membrane phospholipid bi-layer and proteins should not be affected. Then after this every 20�, this will show me how the permeability of the membrane is effected as the temperature increases. I predict that as the temperature increases, the amount of pigment in the water will also increase. I expect that at about 35/40� the concentration of the pigment in the water will get to its maximum, then any higher temperature will be the same or similar to that at it's maximum temperature. ...read more.

Conclusion

Measure 15ml of distilled water into testubes, one for each piece of beetroot. 6. Remove the beetroot from current testubes, discard water and place into new testubes. Leave for 15mins to allow the pigment to diffuse. 7. Pour coloured water into colorimeter tubes put into colorimeter and record reading. PRACTICAL RESULTS Analysis My graph shows a general trend, that as the temperature increases the amount of pigment in the water increases too, however there are three anomalous results, these happen to be the three I had to do on a different day. This is because our lesson time is limited, so we had to finish the experiment in our own time. This is the cause of the anomolous results because by the time I came to finish the experiment, the beetroot was older than before, this could have affected the permeability before I even got to do the experiment. Also when I did the last results there was only enough beetroot to do two samples per temperature whereas before I did three per temperature, so when I took the averages, they would not have been as accurate as the results I took before. ...read more.

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