CK is a _____ (protein unit).

CK is a _____ (protein unit).

• A. Dipeptide
• B. Monopeptide
• C. Tripeptide
• D. Tetrapeptide

Answer: (A)

Proteins are made from amino acids linked together by peptide bonds. A single amino acid isn’t a peptide, so it isn’t a peptide unit. When two amino acids join, they form a dipeptide, the smallest meaningful peptide unit listed here. Three and four amino acids form tri- and tetrapeptides, which are longer chains. Among the given options, the dipeptide is the smallest peptide unit described, so it’s the best match for a “protein unit” in this context. Keep in mind that real proteins are much larger polypeptides, but this question focuses on the smallest peptide fragment.

Proteins are made from amino acids linked together by peptide bonds. A single amino acid isn’t a peptide, so it isn’t a peptide unit. When two amino acids join, they form a dipeptide, the smallest meaningful peptide unit listed here. Three and four amino acids form tri- and tetrapeptides, which are longer chains. Among the given options, the dipeptide is the smallest peptide unit described, so it’s the best match for a “protein unit” in this context. Keep in mind that real proteins are much larger polypeptides, but this question focuses on the smallest peptide fragment.