Can Different Temperature Effect the Cell Membrane

Table of Contents Abstract Introduction Aim Hypothesis Material Method Results Discussion Conclusion? Abstract The aim of this experiment was to see whether different temperatures will affect the cell membrane, thus would then releases the purple pigments out of the vacuole which causes the leakage of the purplish liquid.? Background Information The outermost layer is the cell wall, which is present only in plant cells and is made up of a carbohydrate called cellulose and also has other protein substances embedded within it.

The cell wall is a rigid layer and gives structural stability to the cell and also limits the permeability of large substances into and out of the cell. Within the cell wall, surrounding the cytoplasm is the cell membrane which is a semi-permeable membrane consisting of a phospholipid bilayer. The bilayer consists of phospholipids which arrange themselves so that the hydrophobic (‘water hating’) tails are shielded from the surrounding water. The heads of the molecules are hydrophilic (‘water loving’) and face the water.

Overall, the cell membrane acts to selectively allow substances to move into and out of the cell and maintains the cell potential. Proteins within the membrane act as molecular signals allowing the cells to communicate with each other and other substances outside the cell. About 70% of the cell membrane is actually protein. The cytoplasm of the cell has a number of organelles, although there is one in particular that the vacuole. Vacuoles act to store food for the plant and also assist in structural stability of the plant along with the cell wall.

The vacuoles in plant cells are normally larger than those found in animal cells and contain a fluid called, cell sap. This fluid is rich in nutrients and other substances and is surrounded by a membrane called the tonoplast, separating it from the cytoplasm. The tonoplast is similar in composition to the cell membrane. Biological pigments, also known as pigments or biochromes are substances produced by living organisms that have a colour resulting from the selective colour absorption. The pigments in beetroot are betalain pigments; they are located in the vacuole of the cell.

They are named after the Beet family of plants, but are also found in fungi. In the petals they are thought to attract pollinating insects and may be present in seeds/fruits to encourage birds to eat them and so spreading around the seeds. When a beetroot in heated, it tampers with the cell membranes. A membrane is made of a phospholipid bilayer. These are formed because the phospholipids that make it up have a hydrophilic (‘water loving’) head and a hydrophobic (‘water hating’) tail. The tails pack together, exposing only the heads to the water.

This is the phospholipid bilayer. The beetroot pigment is used commercially as food dye. It changes colour when heated so can only be used in ice-cream, sweets and other confectionary, but it is both cheap and has no known allergic side-effects. Aim To investigate whether different temperatures can damage and denature the plasma cell surface membrane of beetroot cells. This would then release the beetroot pigments out of the vacuole which causes the leakage of the purplish liquid. Hypothesis Beetroot in hotter water will release its pigments more than beetroot in cooler water.

The hotter water should break more vacuoles containing the pigments which will make the water appear to be more purple. Meanwhile the colder water will still have pigments throughout the water, and therefore will be scarcer. Materials -x6 Test Tube -x1 Chopping Board -x1 Serrated Knife -x1 Corer -x6 Skewers -x2 Beetroot -x3 Test Tube Rack -x1 Wooden Test Tube Holders -x1 Bunsen Burner -x1 Match Box -x1 Cork Mat Method 1. Use the corer to get equal cylindrical pieces of beetroot 2. Cut pieces to same size if they are unequal 3. Skewer the beetroot through the middle . Rinse the skewers of beetroot 5. Fill the test tubes to half way with water 6. Place beetroot skewers into test tube and test tubes into test tube holder. Cold 1. Put in fridge and freezer 2. Remove after chosen time, and record your observations. Hot 1. Put over a hot flame and a purple flame 2. Remove after chosen time, and record your observations Results TemperatureColour of WaterColour of Beetroot Room Temperature: 23°C Rich and Dense PurpleDeep Red Not visible through water Fridge: 10°C Partially reddish purpleHot Pink Freezer:-9°C

Very light pink barely any change in the colourVery deep red Blue Flame: 100°C A deep, rich redNormal purple colour Discussion Beetroot in hotter water will release its pigments more than beetroot in cooler water. The hotter water should break more vacuoles containing the pigments which will make the water appear to be more purple. Meanwhile the colder water will still have pigments throughout the water, and therefore will be scarcer. The hypothesis was supported by the results as the beetroot in the hotter water did release more pigments than the beetroot in the colder water.

Some problems that came to attention were the exact sizes of the beetroot pieces could not be made the exact same size. Even though cutting them side by side of each other did make them look similar, the sizes were off still. The experiment as brought sight to what can happen when a fruit or vegetable or flower is heated in water will do. The water colouring process will accelerate more than twice as fast and that could provide big opportunities in some companies. A flaw in the experimental design was that attention wasn’t given to the material of test tubes that were used.

A glass test tube was used for the beetroot that was frozen in the freezer; while in fact a plastic test tube should have been used because the glass test tube could not flex to the expansion of the water in the test tube and so resulting it to crack. Conclusion In conclusion, the hypothesis was supported as the beetroot’s pigments were release more in the hot water more than the cold water did. The hotter water made the beetroot cell vacuoles to burst, releasing the pigments, thus colouring the water.