Question

Three structures are given below in which two glucose units are linked. Which of these linkages between glucose units are between $C-1$ and $C-4$ and which linkages are between $C-1$ and $C-6$ :

• A. $\left(A\right)$ is between $C-1$ and $C-4;\left(B\right)$ and $\left(C\right)$ are between $C-1$ and $C-6$
• B. $\left(A\right)$ and $\left(B\right)$ are between $C-1$ and $C-4,\left(C\right)$ is between $C-1$ and $C-6$
• C. $\left(A\right)$ and $\left(C\right)$ are between $C-1$ and $C-4,\left(B\right)$ is between $C-1$ and $C-6$
• D. $\left(A\right)$ and $\left(C\right)$ are between $C-1$ and $C-6,\left(C\right)$ is between $C-1$ and $C-4$

Answer 1

The correct option is C $\left(A\right)$ and $\left(C\right)$ are between $C-1$ and $C-4,\left(B\right)$ is between $C-1$ and $C-6$

$\left(i\right)$ The first structure is lactose the linkage is $\left(A\right)$ $C_1-C_4$ glycosidic linkage.

$\left(ii\right)$ The $2^{nd}$ structure has $C_1-C_6$ linkages.

$\left(iii\right)$ The $3^{rd}$ structure has $C_1-C_4$ linkages.