Biology 5090 · Question 1[6 marks]
A laboratory technician investigates the biochemical composition of an unknown fresh fruit juice extract.
(a)[2]
Describe the experimental procedure and positive result for testing the juice sample for the presence of reducing sugars.
(b)[2]
The technician uses DCPIP solution to measure the Vitamin C content of the fruit juice. State two variables that must be kept constant to ensure valid comparative results.
(c)[2]
Explain why boiled fruit juice requires a significantly larger volume of juice to decolourise 1.0 cm³ of DCPIP solution compared to fresh unheated fruit juice.