Beetroot practical

• How can you investigate how temperature affects beetroot membrane permeability?

  practical
• what is step 1?

  1. using a scalpel, and chopping board cut 5 equal sized pieces of beetroot. rinse pieces to remove any pigment released during cutting
• what is step 2?

  2. Add 5 pieces to 5 different test tubes, each containing 5cm3 of water (use measuring cylinder/pipette to measure the water)
• what is step 3?

  3. place each test tube in a water bath at a different temp eg 10,20,30etc for the SAME LENGTH OF TIME -measured by a stopwatch
• what is step 4?

  Remove the pieces of beetroot from the tubes-- LEAVE JUST THE COLOURED LIQUID!
• what is step 5?


  Use a colorimeter-

  the higher the absorbance, the more pigment released = the higher the permeability of the membrane
• what is step 6?

  connect the colorimeter to a computer and use software to collect the data and draw a graph of the results
• what do colorimeters need?

  5 minutes to stabilise before using and calibrating at zero by taking a measurement through pure water
• what is a colorimeter?

  a machine that passes light through the liquid and measures how much of that light is absorbed
• the higher the absorbance =?

  the more pigment released so the higher the permeability of the membrane