• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3

# The effect of temperature on Membrane Permeability

Extracts from this document...

Introduction

The effect of temperature on Membrane Permeability It is my aim to investigate whether or not temperature, or more specifically heat, affects the permeability of a cell membrane. Background Based on the fluid mosaic theory we believe the plasma membrane is composed of a phospholipid bilayer about 7-10 nm thick. This theory also suggests that proteins in bedded in the membrane are used for transporting substances across the membrane, creating pores for substances to pass through and act as carriers. Method i. The beetroot must be cut into cylinders and also washed as to remove any anthocyanin pigment that has leaked out the cells because of the cutting, then placed in distilled water ii. Heat 200cm3 of distilled water to 85oC in a sensible sized beaker iii. Whilst the water is heating, use a syringe to place 10cm3 of distilled water into each of ten test tubes. Label the tubes 85,80,75,70,65,63,60,55,50,45 (as these will be the temperatures used) iv. Cut 10 of the cylinder beetroot pieces into lengths of 5cm v. ...read more.

Middle

Results Temp (oC) Percent of light absorbed 85 95 80 92 75 93 70 75 65 17 63 9 60 24 55 11 50 4 45 15 We can see form this table that the percent of light absorbed decreases as the temperature the beetroot was subject to, also decreases. In other words, as the temperature increases, more of the red pigment was able to leave the cell into the distilled water and so the more pigment there was the more light would be absorbed. The above graph clearly shows that the amount of pigment released peaks at 700C, so we can say that at this point the membrane of the beetroot cell becomes severely damaged and a lot of the red pigment that is usually stored in the vacuole of the cell is no longer bound by the internal membrane surrounding the vacuole or the outer membrane. The graph also shows that at 60oC and 45oC the amount of pigment released also increases, however I do not believe that this is a usual occurrence and is an anomalous result. ...read more.

Conclusion

I also think that a different beaker of heated water should be used for each beetroot cylinder, as I found that much of the red pigment was escaping from the cylinder while still being heated, this could effect the results in the way that for the higher temperatures a lot of the pigment has already leaked out, and also that the red pigment in the water may attach to the beetroot cylinders used in the cooler temperatures test, for example at 80oC a lot of the red pigment leaked out of the cell, this would therefore give a lower light absorption rate and give the 50oC cylinder a higher absorption rate as the pigment may have attached to the cylinder while being heated. If I had more time I would like to repeat the experiment three times and gather three sets of results for each temperature and then use the arithmetical mean average. I would also like to test other types of cells using a similar method to examine if temperature effected these in the same way as the beetroot cells. Steven Spencer ...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 Molecules & 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 AS and A Level Molecules & Cells essays

1. ## Beetroot Experiment. The purpose of this experiment is to determine the effect of temperature ...

4 star(s)

Independent variable = Betalain pigment as measured by colorimeter This is the variable that I am trying to measure in order to determine the structural integrity of the plasma membrane. Constant variables In order to make this a fare teat and to ensure that we are measuring the effect of

2. ## The Effect of Ethanol Concentration on the Permeability of Beetroot Cell Membranes to Betalain

3 star(s)

The more transmition percentage, the less blue light is being absorbed and so the less betalain in the solution. Constant Variables There will be some variables which I must ensure remain the same for every part of the experiment as they will have an effect on the results; these are on the following pages.

1. ## Beetroot experiment. Aim: To investigate how the temperature affects the permeability of beetroot cells ...

3 star(s)

All of the above affect the absorbance of light by the beetroot pieces Method: * Firstly gather all apparatus mentioned in the apparatus section * Collect a tile and place it on a flat surface, also collect a strand of raw beetroot, and cut the beetroot into 4 equal sizes

2. ## effect of temperature on beetroot pigment through membrane

3 star(s)

x distilled water - 200 cm3 x ice cubes - 1 x Tripod - 1 X Bunsen burner - 1 x Mat - 1 x White tile - 1 x Scalpel - 1 x Ruler - 1 x Cork borer - 1 x Tongs - 1 x Stop watch -

1. ## Effect of different temperatures on the permeability of beetroot cell membrane.

3 star(s)

Cholesterol determines how fluid the membrane is. It helps to control the fluidity, stopping it from becoming too fluid or too rigid, preventing the membrane from bursting. Cholesterol structure is very similar to a phospholipid, it too has a hydrophilic head and hydrophobic tale, which allows it to fit neatly in the phospholipids.

2. ## An investigation to examine the effects of temperature on membrane stability in beetroot, by ...

3 star(s)

Hydrophilic R-groups are soluble within water and are so water 'loving', whereas hydrophobic R-groups are not soluble in water and are water 'hating'. The properties of the R-groups on amino acids within a protein are very important as they affect the characteristics and functions of the protein.

1. ## TEMPERATURE ON BEETROOT PERMEABILITY

The last anomalous result is for 67�C which has a light transmission of 7%. This is too high percentage light transmission than expected. The error may have been from the shaking of the test tubes, which people did shake and some people didn't.

2. ## An experiment to test the effect of different temperatures on the permeability of cell ...

Cell membrane (Picture gained from Microsoft Encyclopaedia 2002) The cell membrane is often seen as a fluid mosaic model, and it is mosaic due to all the different proteins and cholesterol among the phospholipids. In normal condition the dye would not be able to pass through this complex membrane layer, but when temperature rises and gets above 40�C,

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