biochemical tests

Question 1

reducing sugar

Answer 1

1. add benedict’s to food sample
2. heat

positive test - blue to green/yellow/ red/organge depending on conc. of reducing sugar

Question 2

starch

Answer 2

1. add iodine to food sample

positive test - orange to blue/black

Question 3

lipids

Answer 3

1. dissolve sample in ethanol
2. add distilled water

positive test- white emulsion

Question 4

proteins

Answer 4

1. add biruet solution to sample

positive test - blue to purple

Question 5

non reducing sugar

Answer 5

1. follow negative reducing sugar test
2. add dilute HCL acid and boil to hydrolyse bonds
3. cool and then add sodium hydrogen carbonate to neutralise

positive test- blue to green yellow brick red