Question

question 3
the color change for the biuret reaction from blue to purple indicates protein is present and the darker the shade the more protein there is
true
false
question 4
all proteins will give a positive result for the biurets reaction as it reacts with the peptide bonds between amino acids
true
false
question 5
what color did the egg solution turn when the biuret reagent was added?
blue
yellow
red
purple

Explanation:

• For Question 3: The biuret reaction changes from blue to purple in the presence of protein, and a darker shade indicates more protein. This is a well - known property of the biuret test.
• For Question 4: Biuret reagent reacts with peptide bonds in proteins, so all proteins will give a positive result.
• For Question 5: Egg contains protein. When biuret reagent is added to a protein - containing solution, it turns purple.

Answer:

Question 3: True
Question 4: True
Question 5: purple