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

Answer 1

Answer: (C)

(i) The first structure is lactose the linkage is (A) $C_1-C_4$ glycosidic linkage.
(ii) The $2^{\text{nd }}$ structure has $C_1-C_6$ linkages.
(iii) The $3^{\text{rd }}$ structure has $C_1-C_4$ linkages.