Biochemical Tests Quiz

What does iodine solution test for?

• Lipids

• Proteins

• Starch

• Reducing sugars

What color indicates a positive iodine test for starch?

• Blue-black

• Brick red

• Purple

• Yellow

What does Benedict's solution test for?

• Proteins

• Lipids

• Reducing sugars

• Starch

What is required for a Benedict's test to work?

• Mixing and waiting at room temperature

• Adding heat after mixing

• Adding iodine before testing

• Allowing the solution to sit overnight

What color indicates a positive Benedict's test for reducing sugars?

• Blue-black

• Brick red/orange

• Yellow

• Purple

What does the Biuret test detect?

• Proteins

• Starch

• Lipids

• Reducing sugars

What color indicates a positive Biuret test for proteins?

• Blue-black

• Pink or purple

• Orange

• Clear

What does Sudan IV test for?

• Lipids

• Starch

• Proteins

• Reducing sugars

What is the appearance of a positive Sudan IV test?

• Uniform red throughout the solution

• A purple layer forms

• A reddish-orange layer or droplets

• The solution turns green

What is the method for using iodine solution in testing for starch?

• Heat the solution and add iodine.

• Add iodine directly to the test substance and observe the color change.

• Mix the solution with Benedict's reagent.

• Add iodine and Biuret together to the substance.