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The Membrane And Cytoplasmic Membranes

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The plasma membrane and cytoplasmic membranes of plants, like those of animal cells, are composed of lipids and proteins that are often glycosylated. Likewise, the composition from one membrane type to another is highly diverse. There is some evidence to suggest that the composition, particularly of the lipid component, may change in response to environmental conditions such as temperature, water stress, etc. as well as during growth, development and ultimately senescence of the cell. It is believed that these changes are required to adjust the physical characteristics of membrane structures so that they may perform their necessary physiological tasks when environmental factors change. If the environmental conditions are altered beyond the…show more content…
In this review the importance of lipid phase behaviour is discussed in the context of membrane stability at different temperatures.
The dark red and purple pigments in beetroot are located in the cell vacuole and are chemical compounds called ‘betalains’. The pigments cannot pass through membranes, but can pass through the cellulose cell walls if the membranes are disrupted – by heat (for example cooking) or after a long period pickled in vinegar.
Method:
• First collect a cylinder of beetroot by pushing the corer into the beetroot and withdrawing it. The cylinder remains inside the corer- so push it out with the end of a pencil.
• Collect 6 cylinders, with the pieces of 5 cm long with a segregated knife.
• The beetroot was cut to 5cm. Because the beetroot has been cut some of the cell membranes had been broken, which means some anthocyanin will leak out. This must be completely washed off in order to maintain the reliability of the results.
• The water must then be heated to 70oC (the first temperature for the experiment)
• Once the water is at the correct temperature (measured using the thermometer), one piece of beetroot is placed into the hot water, in a test tube, directly and left for exactly 2 minute (using a stopwatch).
This procedure will be repeated with the other 5 pieces of beetroot and the temperature should be changed accordingly. The temperatures will be
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