# DBT JRF 2022 — Question 13

Exam: DBT JRF 2022 · Section: B · Topic: Biochemistry › Carbohydrate Structure & Molecular Formula · Difficulty: Medium

## Question

Given the molecular structure of glucose, the molecular formula and molecular weight of maltose will be: ![figure](https://res.cloudinary.com/dxil5euku/image/upload/v1779453119/pyq/6a104cb5920734408bc0c6d8/DBTJRF22-IMGB13.png)

## Options

- **A.** $C_{12}H_{24}O_{12}$ , 360 Daltons
- **B.** $C_{12}H_{24}O_{12}$ , 460 Daltons
- **C.** $C_{12}H_{22}O_{11}$ , 342 Daltons
- **D.** $C_{12}H_{22}O_{11}$ , 490 Daltons

## Answer

Option C

## Explanation

Molecular formula and weight of maltose from glucose: Glucose structure: $\text{C}_6\text{H}_{12}\text{O}_6$ , MW = 180 Da Maltose = glucose + glucose joined by an $\alpha(1\rightarrow 4)$ glycosidic bond, with one water molecule released: $\text{Maltose formula:} \; 2 \times \text{C}_6\text{H}_{12}\text{O}_6 - \text{H}_2\text{O} = \text{C}_{12}\text{H}_{24}\text{O}_{12} - \text{H}_2\text{O} = \text{C}_{12}\text{H}_{22}\text{O}_{11}$ $\text{MW} = 2 \times 180 - 18 = 360 - 18 = 342\,\text{Da}$ Answer: $\text{C}_{12}\text{H}_{22}\text{O}_{11}$ , 342 Da (Option 3).

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