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Membrane Permeability

In: Business and Management

Submitted By nourelkholy123
Words 528
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The effect of temperature on membrane permeability in beetroots

Temperature ±1 (oC) | Absorption ±0.001 and observations | 30 | .886Water stained purple halfway through the test tube | 40 | .238Beetroot turned yellow-orange, water also stained yellow-orange | 50 | .140Water stained dark purple | 60 | .109Water stained lighter purple than 50C, beetroot lost color slightly and floating in middle of water | 70 | .056Water stained red-orange especially near the bottom, beetroot lost color almost completely, beetroot floating near top of water | 80 | .010Water stained light pink, beetroot lost all color and is floating at top of water | 100 | .030Water stained light pink (similar to 30C) and beetroot lost color and is floating at top of water |

Conclusion: Our results support that as the temperature increased, the permeability of the beetroot also increased, due to destruction of the membrane. We can see this through the curve on our graph; our readings from the colourimeter showed that light absorption decreased as the temperature increased, meaning that the solution was more concentrated due to more of the pigmented substance from the beetroot vacuole leaking through the destroyed beetroot membrane. This was also evident through observation of the different solutions of water (as the temperature of water increased, the extent of pigmentation of the water increased). For 20oC, we obtained a reading of .886, which decreased to .238 by 40oC, and eventually to .010 by 80oC. However, for 100oC we obtained an anomalous result; the reading on the colourimeter increased from 0.010 to 0.030. This could be due to a fault with the colourimeter, or failure to calibrate it before taking the reading. An experiment carried out by A. B. Hope and A. P. Aschberger on the effects of temperature on membrane permeability to ions further supports our results and conclusion.


Limitation | Effect | Improvement | Systematic | Inaccurate calibration of the colourimeter | Incorrect readings and decreased validity and accuracy of results | Carefully calibrate the colourimeter before each reading | Beetroot pieces were not all exactly the same measurements | Caused different surface areas therefore different volumes of permeable membrane to be destroyed/affected, leading to inaccurate results | Weigh the beetroot pieces before the experiment, or use a shaped vegetable slicer so that all pieces are equal in size | Random | Time constraint | Not enough time to acquire many results or repeat the experiment, causing reduced reliability of the results | Conduct the experiment over a longer period of time to allow for more readings and repetition | Inconsistent temperature of water through uncertainty of thermometer and constant changing temperature | Results were affected due to the temperature not being set | Use water baths |

The effect of chemicals on membrane permeability in beetroots

Chemicals and their pH | Observations | HCl1.00 | Pink pigment has stained the acid, beetroot itself has lost some pigmentation | NaOH13.26 | Beetroot has turned yellow, NaOH also stained yellow | Cyclohexane6.92 | Beetroot has lost its color (turned grey), secreted purple liquid resting at bottom of test tube, volume of cyclohexane decreased significantly | Acetone8.10 | Beetroot has been eaten and turned brown, secreted orange liquid staining the acetone, volume of acetone decreased by almost half | Ethane6.57 | Volume decreased slightly, beetroot turned red and stained the ethane red |

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