The effect of temperature on cell membranes

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Independent: Water temp.

Dependent: % transmission light through resulting solution

Control:

Vol. distilled water

Time

left in water

Size beetroot pieces

Method:

Use corkborer & knife, cut beetroot into 1cm length cylinders.

Place in distilled water overnight remove dye released preparation.

Wash & blot dry.

Place 8 boiling tubes distilled

water into 8 water baths different temp.

Once at temp., add piece to each & leave 30mins.

Remove beetroot & shake tubes disperse dye.

Set colorimeter to % absorbance on

blue/green filter.

Calibrate use distilled water in cuvette first then add 2cm3 of beetroot from first temp. to new

cuvette.

Place into colorimeter to read %

absorbance.

Repeat for all other pieces.

Calculations & outcome:

%

transmission = 100 - % absorbance.

Temp. increased, % transmission

slightly increased to point which greatly increased due membrane

molecules gain more heat energy, vibrate to point where vibrations cause

large gaps in the membrane enable release dye & proteins in

membrane denatured leaving large pores.

Evaluation issues:

Accurate

size beetroot

Parts of root

Some have skin affect surface area

Difficult maintain temp.

Ensure same amount time at diff. temp.

Accurate read. colorimeter

Method