Collagen — Amino Acid Composition

Collagen is a rich source of:

Correct Answer: Glycine, Proline, Hydroxyproline

Collagen is a rich source of Glycine, Proline, and Hydroxyproline. These three amino acids are uniquely abundant in collagen and are responsible for its triple-helix structure.

Collagen's Unique Features

• Glycine (~33%): Every 3rd residue; essential for helix formation
• Proline and Hydroxyproline (~22%): Stabilize the triple helix; Hydroxyproline is almost exclusive to collagen — it is used as a marker for collagen content in food analysis
• Deficient in: Cysteine and Tryptophan

Hydroxyproline as a Collagen Marker

Since hydroxyproline is found almost exclusively in collagen, measuring hydroxyproline content in food products is a standard analytical technique to determine collagen/connective tissue content.