Cho X là hexapeptit, Ala-Gly-Ala-Val-Gly-Val là Y là tetrapeptit Gly-Ala-Gly-Glu.

\(X : Ala - Gly - Ala - Val - Gly - Val \rightarrow 2 Gly + 2 Ala + 2 Val\)

\(a\hspace{225pt}2a\hspace{30pt}2a\)

\(Y: Gly - Ala - Gly- Glu \rightarrow 2 Gly + Ala + Glu\)

\(b\hspace{155pt}2b\hspace{30pt}b\)

 \(n_{Gly}=\frac{30}{75}= 0,4 mol = 2a + 2b\)

_{\(n_{Ala}=\frac{28,48}{89}= 0,32 mol = 2a + b\)}

_{\(\begin{align*} \begin{cases} 2a+2b=0,4 \\ 2a+b = 0,32 \end{cases} \end{align*} \Rightarrow \begin{align*} \begin{cases} a=0,12 \\ b = 0,08 \end{cases} \end{align*}\)}

\(m = a.M_{hex} + b.M_{tetra} = 0,12.472+0,08.332 = 83,2 ( gam )\)