Study Of The Enviroment On The Cell Membrane Essays -

Study Of The Enviroment On The Cell Membrane Study Of The Enviroment On The Cell Membrane Dave Lima SBI OA1 Mr. Swanson 10/4/99 Purpose: To study the effect of environmental changes in the permeability of living beet root cells. Procedure A: The effect of pH on the cell membrane Materials & Method 1. Cut a beet root into slices approximately 2mm thick. Use a cork bore to cut out thirty-five (35) slices. 2. Place the discs in a 250 mL beaker and rinse thoroughly in cool running tap water. The red pigment collected comes from the damaged cells and can be used to analyze the chemical nature of the pigment. 3. The pigment in a beet, anthocynanin, should be analyzed before beginning. This can be done simply by first adding a few drops if concentrated acid to a sample if beet juice. 4. The resulting solution can be compared to a second sample made by adding a few drops if concentrates base to another sample of beet juice. Note the colours of each. Given stock solutions of 0.1 mol/L HCl and 0.1 mol/L NaOH, and graduated cylinders, prepare the following solutions in separate test tubes. a) 10 mL of 0.1 mol/L HCl b) 10 mL of 0.01 mol/L HCl c) 10 mL of 0.001 mol/L HCl d) 10 mL of distilled water e) 10 mL of 0.001 mol/L NaOH f) 10 mL of 0.01 mol/L NaOH g) 10 mL of 0.1 mol/L of NaOH 5. Place five (5) beet root discs in each of the 7 test tubes. 6. Leave them for 15 minutes and then record your observations. Agitate gently and continue to observe them at 15-minute intervals until no further changes occur. Procedure B: The effects Of An Organic Solvent Materials & Methods 1. Prepare beet root discs as for Procedure A. The number required will depend on the control you design. 2. Place five (5) of the discs in a test tube containing 10 mL of distilled water and 2 mL of ethanol. 3. Design a control for this investigation. 4. Agitate gently and periodically for 15 minutes and record your observations. Observations: Analyzing anthocynanin by adding concentrated acid and base to beet juice Mixture Observations recorded Few drops of concentrated acid added to a sample of beet juice -Concentrated acid caused the anthocynanin to turn to a slightly lighter shade of pink. Few drops of concentrated vase added to a sample of beet juice -Concentrated base caused the anthocynanin to turn a transparent yellow. Serial Dilution Intervals 0.1 mol/L 0.01 0.001 Distilled` 0.001 0.01 0.1 HCl mol/L mol/L Water mol/L mol/L mol/L HCl HCl NaOH NaOH NaOH 15 -lots of -less pigment -a small -very little -a small -barely -a yellow Minutes pigment lost lost than the amount pigment lost amount any pigment is -solution is dark 0.1 solution of from the beet of pigment present in purple in of HCl pigment root pigment lost the colour lost lost from the solution from the from the beet root beet root beet root 30 -slightly -slightly -slightly -slightly -slightly -slightly -slightly Minutes more more more more more more more Pigment pigment pigment pigment pigment pigment pigment lost since lost since lost lost since lost lost lost the the since the the since since since observation observations obser- observations the the the made at made at vations made at observ- observ- observ- 15 minutes 15 minutes made at 15 minutes ations ations ations 15 made at made at made at minutes 15 15 15 minutes minutes minutes 45 -solution -solution -solution -a darker shade -solution -solution -the Minutes is dark is pink in is a of pink than is a light is a light mixture is purple in colour lighter the 0.001 pink pink very colour throughout shade of solution of through- through- yellow throughout pink HCl but not out the out the throughout than that of the mixture, mixture, the actual the 0.01 0.01 solution similar similar beet have solution of HCl to that to that turned of HCl of the of the brown in 0.001 0.001 colour mol/L mol/L HCl HCl The Effects Of An Organic Solvent: Designing A Control The control our group designed for this investigation was to have one test tube with 10 mL of distilled water 2 mL of ethanol. This way both test tubes would have a total of 12 mL and 5 beet roots each. Test tube with 12 mL of water Test tube with 10 mL of water and 2 mL of ethanol -very little pigment lost -light pink in colour -beets moved (twirled) when agitated -very little