Which nutrient contains nitrogen as a defining element?

Which nutrient contains nitrogen as a defining element?

• A. Carbohydrates
• B. Lipids
• C. Minerals
• D. Proteins

Answer: (D)

Nitrogen is a defining element in proteins. This comes from amino acids, the building blocks of proteins, each of which contains an amino group that includes nitrogen. The bonds that link amino acids together—the peptide bonds—involve nitrogen as part of the backbone of proteins. Carbohydrates and lipids are made mainly of carbon, hydrogen, and oxygen, with no nitrogen as a defining component, and minerals are inorganic elements that do not include nitrogen in their basic composition. So proteins are the nutrient that contains nitrogen as a defining element.

Nitrogen is a defining element in proteins. This comes from amino acids, the building blocks of proteins, each of which contains an amino group that includes nitrogen. The bonds that link amino acids together—the peptide bonds—involve nitrogen as part of the backbone of proteins. Carbohydrates and lipids are made mainly of carbon, hydrogen, and oxygen, with no nitrogen as a defining component, and minerals are inorganic elements that do not include nitrogen in their basic composition. So proteins are the nutrient that contains nitrogen as a defining element.