Cell Membrane

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
pigment lost -only a light tint of pink could be seen -beets did not move when
agitated, they remained