Biomolecules and Chemistry in Everyday Life 1 Question 32
34. A decapeptide (Molecular weight 796) on complete hydrolysis gives glycine (Molecular weight 75), alanine and phenylalanine. Glycine contributes $47.0 %$ to the total weight of the hydrolysed products. The number of glycine units present in the decapeptide is
(2011)
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Solution:
- A decapeptide has nine peptide (amide) linkage as
Therefore, on hydrolysis, it will absorb nine water molecules.
Hence, total mass of hydrolysis product $=796+18 \times 9=958$
$\Rightarrow$ mass of glycine in hydrolysis product $=\frac{958 \times 47}{100}=450$
$\Rightarrow$ number of glycine molecule in one
molecule of decapeptide $=\frac{450}{75}=6$
