The effect of temperature on the membrane structure of beetroot

GCSE: Biology

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Independent:

The independent variable is the temperature level the beetroot is placed in as this is what we are manipulation to see whether there is a change in how many betalains are taken out.

Fixed:

The fixed variables would be the:
• Equipment usage and set up
• The beetroot size(1cm^2), each piece will be the same size
• The time the beetroot is exposed to the temperature environment
• We extrectes pieces of beetroot from the same singular beetroot piece, and thus they all av similar properties.

Fair test:

• Repeat each temperature three times with different pieces of beetroot, so as to get the most closest true value
• The structure of the equipment shall not be moved.
• The timing.
• The beetroot size, each piece will be the same size
• The time the beetroot is exposed to the temperature environment
• The time the beetroot are left overnight to wash away any excess dye
• The amount of distilled water is placed into a cuvette make sure each time it is only 2cm3
• The amount of dye solution is placed into the colorimeter cuvette- 2cm3



Risk Assessment:

• Do not eat beetroot as it may be contaminated
• Be careful not to burn fingers hwn using laserlaser
• Do not run with test tubes, hot or not. It may smash
• Tie up hair, wear flat shoes and , and do not wear long necklaces
• Be careful where test tubes are placed on the table, as they may roll and shatter.
• Be careful not to spill bettroot juice on your skin or clothing as it will stain very badly.
• The water baths are placed well away from the edge of the table, so it is nto pushed over
• Be careful when cutting the beetroot
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Apparatus:
• Raw beetroot, cut into different sizes
• White tile
• Size 4 cork borer
• Ruler
• Beaker
• Distilled water
• Lebells for test tubes, and a pen
• Paper and pen and ready graph to jot down results
• 8 prepared water baths at chosen temeprtures
• X16 boiling tubes
• Pointed seeker
• Colorimeter
• Cuvette

Method:
1 Cut sections from a single beetroot using a size 4 cork borer. Cut eight, 1 cm length slices from these sections. Be careful not to spill beetroot juice on your skin or clothing as it will stain very badly.
2 Place the slices in a beaker of distilled water. Leave overnight to wash away excess dye.
3 Next day, place eight labelled boiling tubes each containing 5 cm3 distilled water into water baths at 0 °C, 10 °C, 20 °C, 30 °C, 40 °C, 50 °C, 60 °C and 70 °C. Leave for 5 minutes until the water reaches the required temperature. Place one of the beetroot sections into each of the boiling tubes. Leave for 30 minutes in the water baths.
4 Decant the liquid into a second boiling tube or remove beetroot sections using a technique that does not squeeze the slice e.g. spear with a pointed seeker. Shake the water/solution to disperse the dye.
5 Switch on the colorimeter and set it to read % absorbance.
6 Set the filter dial to the blue/green filter.
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