Question

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Sucrose is a disaccharide and a non-reducing sugar.
Reason (R): Sucrose involves glycosidic linkage between $C_1$ of $\beta$-glucose and $C_2$ of $\alpha$-fructose.

The most appropriate answer from the options given below :

• A. Both $\left(A\right)$ and $\left(R\right)$ are true and $\left(R\right)$ is the true explanation of $\left(A\right)$
• B. $\left(A\right)$ is false but $\left(R\right)$ is true
• C. Both $\left(A\right)$ and $\left(R\right)$ are true but $\left(R\right)$ is not the true explanation of $\left(A\right)$.
• D. $\left(A\right)$ is true but $\left(R\right)$ is false

Answer 1

The correct option is D $\left(A\right)$ is true but $\left(R\right)$ is false

Sucrose is a disaccharides and a non-reducing sugar because it does not contain free hemiacetal linkage.
Thus, both the $OH$ group at the anomeric carbon of glucose and fructose forms gylcosidic linkage.
Hence, it the glycosidic linkage of $C_1$ of $\alpha$-D-glucose and $C_2$ of $\beta$-D- fructose.

Hence, (b) is correct.