Investigate membrane structure and effect of temperature on membrane permeability
Independent variable?
Temperature of water baths (0°C, 10°C, 20°C, 30°C, 40°C, 50°C )
Dependent variable?
Percentage transmission of light through the solutions
Control Variables?
Volume of distilled water for each boiling tube (10cm3)
Time left in water baths (30 mins)
Size of beetroot (1cm) - cylindrical
Age or source of beetroot
same colorimeter with same settings
Same volume of beetrootsolution added to cuvette (2cm3)
Control?
Keep a boiling tube containing beetroot and distilled water in room temperature and use colorimeter.
Why beetroot?
Betalain is a pigment in the vacuole of a beetroot cell. As membrane permeability increases, the pigment begins to leak which can be measured, using a colorimeter.
Conclusions?
As temperature increases, the percentage transmission also increases, indicating that membrane permeabilityincreases.