Question

question 9
what were the positive and negative controls for this experiment?
glucose and water
vegetable oil and apple
egg and water
bread and glucose

question 10
now that you are familiar with the biuret test and know how the reagent reacts with the peptide bonds in the protein to give a positive color change, hypothesize whether the following foods would produce a positive test and you must explain why in terms of the presence of peptide bonds in the protein
fish
pasta
butter
kidney beans
amino acid solution
for the toolbar, press alt+f10 (pc) or alt+fn+f10 (mac).
b i u s paragraph open sans,a... 10pt

Explanation:

For Question 9: In many biochemical experiments, glucose can be a positive - control for sugar - related tests and water is often a negative - control as it contains no relevant substances for such tests. For Question 10: Fish contains protein with peptide bonds, so it will give a positive Biuret test. Pasta mainly consists of carbohydrates and has little protein, likely a negative test. Butter is a fat and has no peptide bonds, so negative. Kidney beans have protein and will give a positive test. Amino acid solution has no peptide bonds (except in some di - or poly - amino acid cases), usually negative.

Answer:

Question 9: A. glucose and water
Question 10:
Fish: Positive, contains protein with peptide bonds.
Pasta: Negative, mainly carbohydrates, little protein.
Butter: Negative, is a fat, no peptide bonds.
Kidney Beans: Positive, contains protein.
Amino acid solution: Negative, no peptide bonds (usually).