Most american diets emphasize ________ as the main nutrient.
a. carbohydrates.
b. protein.
c. fat.
d. vitamins user: polypeptide contain ______.
a. two amino acids joined by peptide bonds.
b. four amino acids joined by peptide bonds.
c. five to ten amino acids joined by peptide bonds.
d. more than ten amino acids joined by peptide bonds