The effect of temperature on cell membranes

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