To correctly identify unknown biomolecules in a laboratory setting, specialized diagnostic chemical — Biomolecules Chemistry Question
Question
To correctly identify unknown biomolecules in a laboratory setting, specialized diagnostic chemical tests are heavily employed. Which of the following standard biochemical tests specifically and reliably identifies the distinct presence of the intact peptide linkage ($-CO-NH-$) directly within complex proteins?
💡 Solution & Explanation
The Biuret test reliably utilizes alkaline $CuSO_4$ solution to precisely detect the intact presence of multiple sequential peptide bonds, rapidly yielding a distinctive deep violet/purple complex strictly with proteins. The Ninhydrin test merely identifies free $\alpha$ -amino groups broadly.