Located within the vacuole of Beta vulgaris rubra cells is a ruddy pigment call Betalains. Typically these pigments are contained within the cell vacuole by the tonoplast ( vacuole membrane ) . nevertheless When Beta vulgaris rubra is heated these ruddy pigments escape the vacuole. This experiment aims to research the consequence of temperature on the permeableness of the cell membranes ( i. e. Tonoplast ) . ‘The cell surface membrane is the plasma membrane that surrounds cells and forms the boundary between the cell cytol and the environment… . . It controls the motion of substances in and out of the cell. ’ ( Glen Toole and Susan Toole. 2008. p. 552 ) . The tonoplast is indistinguishable to the cell surface membrane except it surrounds merely the vacuole. compared to the cell surface membrane which surrounds the full cell. A plasma membrane is made up of a phospholipid bilayer. Each bed which consists of a hydrophobic fatty acid tail and a hydrophilic phosphate caput. Each bed
• Size 4 Cork Borer
• White Tile
• Water Baths ( 0°C. 10°C. 20°C. 30°C. 40°C. 50°C. 60°C. 70°C )
• Plastic Beaker ( ~250cm3 )
• 2 Boiling Tube Racks
• 8 Boiling Tubes
• Crushed Ice
• 8 Thermometers ( one per H2O bath )
• Distilled Water
( N. B. – All personal protective equipment must be worn and care must be taken when utilizing the cork bore bit or Scalpel/knife. All research lab regulations must be followed )
Eight cylinders where cut from the Beetroot. utilizing a cork bore bit. and so cut to 1cm utilizing a knife or scalpel. Eight H2O baths were set up at temperatures of 0°C. 10°C. 20°C. 30°C. 40°C. 50°C. 60°C and 70°C. The 50 60 and 70 H2O baths were maintained electrically whereas the remainder were manual. Eight boiling tubings were taken and labelled harmonizing to its corresponding H2O bath and filled with 5cm3 and left in its duplicate H2O bath for 5 proceedingss to let acclimatization of the distilled H2O. After five proceedingss one of the eight 1cm long cylinders of Beta vulgaris rubra was placed in each of the boiling tubings and left for the 30 proceedingss in the H2O baths. After 30 proceedingss the Beta vulgaris rubra pieces were removed from the boiling tubings and the tubings were shaken to scatter the dye. Then utilizing a pipette approx. 2cm3 of the solution from each of the trial tubing was taken and placed in a cuvette. with attention taken to maintain solutions of different temperatures separate. The cuvette was so placed in a tintometer. guaranting the smooth sides were confronting the light beginning. and the optical density of the solution was measured. Before each measuring the tintometer was calibrated to an absorbency of nothing utilizing a cuvette of distilled H2O. This was done for the cuvettes of each of the temperatures.
|Temp. |Absorbance |
| ( Initial ) /°C | |
|0 |0. 12 |
|10 |0. 15 |
|20 |0. 23 |
|30 |0. 21 |
|40 |0. 26 |
|50 |0. 39 |
|60 |1. 70 |
|70 |1. 96 |
The general tendency followed by the consequences is. that as the temperature addition. the permeableness of the cell membranes besides increases. This is indicated by the fact that in the consequences when temperature increases the optical density of the solution in the tintometer besides increases. proposing a deeper color of the solution and hence greater concentration of the pigment Betalains within the solution. This indicates that at a higher temperature. a greater sum of Betalains was allowed to ooze out of the cell vacuole and into the environing environment.
As temperature increased. the permeableness of the cell membranes besides increased as shown by the general tendency of the consequences. This is due to the fact that as the temperature was raised. the kinetic energy of the phospholipids within the cell membranes besides increases. doing greater random motion of the phospholipid bilayer. this consequences in big holes within the bilayer doing the partly permeable membrane to go more permeable. The Betalains so diffused through the tonoplast and out of the vacuole. which is a part of high concentration. and into the distilled H2O. which is a part of low concentration. down a concentration gradient. The higher the temperature that the Beta vulgaris rubra cylinder is exposed to. the greater the harm to the cell membranes and the greater the permeableness of the cell.
The consequences we gained were non wholly dependable since there were
many factors that weren’t taken into history and many mistakes which may hold occurred. Possible Mistakes
• Cylinders of Beetroot may non hold been cut accurately. as they were cut utilizing a swayer which is merely accurate to 1 millimeter. ensuing in a greater or smaller surface country. which would hold had an consequence on the rate of diffusion of the Betalains once the cell membranes had become permeable. • There were some proficient troubles when utilizing the tintometer. For illustration the tintometer may non hold been calibrated right. the tintometer may non hold been on the right scene. and the cuvettes may hold been placed in the tintometer in the incorrect place. i. e. the smooth side non confronting the light beginning. Besides this trial suffered from some unknown internal job of the tintometer and since this was non solved some liability of the anomalous consequences lies in this part amongst others.