Tests

Question 1

What does benedicts test for?

Answer 1

Reducing and non-reducing sugars

Question 2

Method for testing for reducing? Results if present?

Answer 2

1)place sample in boiling tube
2)add drops of benedicts
3) heay mixture in hot water bath for 5 minutes
RESULTS- red precipitate will form

Question 3

What would you have to fo before the method for benedicts if the sugar is non reducing?

Answer 3

It would have to be hyrdrolysed by boiling it with dilute hydrochloric acid and them neutralided with sodium hydrogen carbonate

Question 4

What is the tesy for proteins? Results if positive?

Answer 4

-Biuret solution
- solution will turn from blue to lilac

Question 5

Test for lipids? Results if positive?

Answer 5

-emulsion test: add ethanol to sample and shake vigourously
- white precipitate forms if lipids present

Question 6

What is the test for starch? Results if positive?

Answer 6

• iodine solution
• solution turns from orange to black