Study Of The Enviroment On The Cell

Membrane Essay, Research Paper

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

MixtureObservations 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/L0.010.001 Distilled`0.0010.01 0.1

HClmol/Lmol/L Watermol/Lmol/L mol/L

HClHClNaOHNaOH NaOH

15 -lots of-less pigment-a small -very little-a small-barely -a yellow

Minutespigment lostlost than the amount pigment lostamountany pigment is

-solution is dark0.1 solutionof from the beetofpigment present in

purple inof HClpigment rootpigmentlost the

colourlost lostfrom the solution

from thefrom thebeet root

beet rootbeet root

30-slightly-slightly-slightly-slightly-slightly-slightly-slightly

Minutesmoremoremoremoremoremoremore

Pigmentpigmentpigmentpigmentpigmentpigmentpigment

lost sincelost sincelost lost sincelostlostlost

thethesince the thesincesincesince

observationobservationsobser-observationsthethethe

made atmade atvationsmade atobserv-observ-observ-

15 minutes15 minutes made at15 minutesationsationsations

15made atmade atmade at

minutes151515

minutesminutesminutes

45-solution-solution-solution-a darker shade-solution-solution-the

Minutesis darkis pink inis a of pink thanis a lightis a lightmixture is

purple incolourlighterthe 0.001pinkpinkvery

colourthroughoutshade ofsolution ofthrough-through-yellow

throughoutpink HCl but notout theout thethroughout

thanthat of the mixture,mixture,the actual

the 0.010.01 solutionsimilarsimilarbeet have

solutionof HClto thatto thatturned

of HClof theof thebrown in

0.0010.001colour

mol/Lmol/L

HClHCl

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 waterTest 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 at the bottom of the test tube

-traces of oil were present in the test tube

Discussion

1. What relationship exists between the concentration of acid or base solution and the pH?

In a solution, pH refers to the concentration of H+ ions. The pH is expressed as a positive number while the concentration of the H+ ions is taken in exponent form. Bases start at as low as 10-14 and acids are up to 1. Therefore taking the pH from the concentration is determined by taking the negati

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