Practical 2

Question 1

In 7 steps how do you Investigating the Effect of pH on Amylase Activity (PRATICAL)?

Answer 1

• 1) Add Iodine to a spotting tile.
  -2) Add Amylase, Buffer solution with PH of 5 to a Boling tube.
• 3) Place the tube in an 35° water bath for 5 Minutes.
• 4) Add Starch to the boiling tube and mix and start a stopwatch.
• 5) Every 30 Seconds take a sample from the boiling tube using as pipette and put a drop of sample into the spotting tile.
• 6) If the iodine stays brown-orange, starch is fully broken down.
• 7) Repeat with different PH Values and measure how PH affects starch breakdown time.

Question 2

For the food group sugar and** glucose**, what are the chemical tests, special conditions required, and the colour changes?

Answer 2

• Chemical:Benedict’s Solution.
• Special Condition: Heat It to 80°.
• Colour Change: Blue - Brick Red

Question 3

For the food group Protein what are the chemical tests, special conditions required, and the color changes?

Answer 3

• Chemical:Biuret Solution
• Special Conditions:No Special Conditions.
• Colour Change:Blue - Lilac Purple.

Question 4

For the food group Starch what are the chemical tests, special conditions required, and the color changes?

Answer 4

• Chemical:Iodine.
• Special Conditions:No Special Conditions.
• Colour Change: Orange/Brown - Blue Black or Black.

Question 5

For the food group Lipids what are the chemical tests, special conditions required, and the color changes?

Answer 5

• Chemical:Sudan 3
• Special Conditions:No Special Conditions.
• Colour Change: Red Layers Form

Question 6

Name 5 Steps To Use The Benedicts Test to test for Sugars (PRACTICAL) Food Tests 2?

Answer 6

• 1) Prepare a Food Sample And Transfer 5 cm³ to a test tube.
• 2) Prepare a Water Bath at 75°.
• 3) Add Some Benedict Solution To The Test Tube About 10 Drops Using a Pipette.
• 4) Place The Test in the Water Bath Using a Test Tube Holder and Leave It for 5 Minutes.
• 5) the Solution In The Test Tube Will Change from The normal blue colour to green,Yellow or Brick Red.

Question 7

Name 3 Steps to Test For Starch (PRACTICAL) - Food Tests 3?

Answer 7

• 1) Make a Food Sample and Transfer 5 cm³ to a Test Tube.
• 2) Add a Few Drops Of Iodine Solution Gently Shake The Tube to Mix It Up.
• 3) If The Sample Contains Starch the Solution will Change From Brown-Orange to Black or Blue -Black.

Question 8

Name 3 Steps to Test For Proteins (PRACTICAL) - Food Tests 4?

Answer 8

• 1) Prepare a Sample of Your Food And Transfer 2 cm³ To a Test Tube.
• 2) Add 2 cm³ of Biuret Solution to the Sample Gently Shake It.
• 3) If The Food Sample Contains Protein The Solution will change from blue to Purple.

Question 9

Name 3 Steps to Test For Lipids (PRACTICAL) - Food Tests 5?

Answer 9

• 1) Prepare a Food Sample By Breaking The Food Using a Pestle and Mortar But Don’t Filter It Transfer 5 cm³ to a Test Tube.
• 2) Add 3 Drops of Sudan 3 Solution to the test tube and Gently Shake It.
• 3) If The Sample Contains Lipids the Mixture Will Separate out Into 2 Layers And The Top Layer will Be Bright Red.