CPAC Experiments

Question 1

EQ. Devise a procedure that can be used to investigate the effect of cooking on the vitamin C content of cauliflower. (4 marks)

Answer 1

• take extracts from uncooked and cooked cauliflower
• measure the volume of extract needed to decolourise the DCPIP solution
• use the same volume of DCPIP solution for accuracy
• we can find the vitamin C content in the uncooked and cooked cauliflower by comparing it to the vitamin C calibration curve

Question 2

Name the formula for magnification

Answer 2

Magnification=Image/Actual

Question 3

How to get from mm to µm

Answer 3

x1000

Question 4

EQ. The effects of plant extracts were tested on pathogenic bacteria. Devise a procedure that scientists may have used to measure the effects of these extracts on pathogenic bacteria. (4 marks)

Answer 4

• have agar plates inucluated with bacteria
• dip filter paper disks in the plant extracts and then place in the agar plate
• incubate at 37*C for 24 hours
• compare and measure the diameters of the zone of inhibition
• the larger the zone of inhibition the more effective its antimicrobial properties are