Given below are two statements. Statments I: Maltose has two $\alpha$-D-glucose units linked at $\mathrm{C}_{1}$ and $\mathrm{C}_{4}$ and is a reducing sugar. Statement II: Maltose has two monosaccharides: $\alpha$-D-glucose and $\beta$-D-glucose linked at $\mathrm{C}_{1}$ and $\mathrm{C}_{6}$ and it is a non-reducing sugar. In the light of the above statements, choose the correct answer from the options given below.

(A) Both Statement I and Statement II are true

(B) Both Statement I and Statement II are false

(D) Statement I is false but Statement II is true

JEE Main · 2022 · 27 Jun 2022 · Shift 2 · Biomolecules

Given below are two statements.

Statments I: Maltose has two

α

-D-glucose units linked at

C_{1}

and

C_{4}

and is a reducing sugar.

Statement II: Maltose has two monosaccharides:

α

-D-glucose and

β

-D-glucose linked at

C_{1}

and

C_{6}

and it is a non-reducing sugar.

In the light of the above statements, choose the correct answer from the options given below.

(A)Both Statement I and Statement II are true
(B)Both Statement I and Statement II are false
(C)Statement I is true but Statement II is false✓ Correct
(D)Statement I is false but Statement II is true

Answer: (C)

Solution

Statement I is correct: Maltose consists of two α-D-glucose units linked by an α(1→4) glycosidic bond. Since one anomeric carbon (C₁ of the second glucose) remains free, maltose is a reducing sugar.

Statement II is false: Maltose does not have α and β glucose units linked at C₁ and C₆. That description would be closer to isomaltose or gentiobiose. Maltose has α(1→4) linkage, not (1→6), and both units are α-D-glucose.

Answer: (C) Statement I is true but Statement II is false

JEE Main · 2022 · 27 Jun 2022 · Shift 2 · Single correct option

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JEE Main · 2022 · 27 Jun 2022 · Shift 2 · Biomolecules

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