Which of the following contains amino acids?

The correct answer is Collagen. Collagen is a protein, and proteins are made up of amino acids linked together. Collagen is the most abundant protein in the human body, found in skin, bones, and connective tissues. Among the options:

• Collagen: Correct; it contains amino acids as it is a protein.
• Starch: A carbohydrate made of glucose units, not amino acids.
• Glucose: A simple sugar, not an amino acid.
• Cellulose: A carbohydrate (polysaccharide) found in plant cell walls, not made of amino acids.

Hence, the correct answer is "Collagen".