Glycosidic linkage is :

Options

A. amide linkage
B. ester linkage
C. ether linkage
D. acetyl linkage.

Answer

**Step-by-Step Solution:**

1. **Understanding Glycosidic Linkage**: Glycosidic linkage is a type of covalent bond that connects two monosaccharides (sugar units) to form a disaccharide or polysaccharide. This bond is formed through a dehydration reaction, where a water molecule is removed.

2. **Example of Glycosidic Linkage**: To illustrate this, we can use the example of maltose, which is formed from two units of alpha-D-glucose. Each glucose molecule has hydroxyl (OH) groups that will participate in the formation of the glycosidic bond.

3. **Formation of Maltose**: When two alpha-D-glucose molecules come together, the hydroxyl group on the first glucose (at the C1 position) reacts with the hydroxyl group on the second glucose (at the C4 position). During this reaction, a water molecule (H2O) is removed.

4. **Resulting Structure**: After the removal of water, an oxygen atom remains that connects the two glucose units. This bond is what we refer to as the glycosidic linkage. The structure can be represented as follows:
- R1 - O - R2, where R1 and R2 represent the remaining parts of the glucose molecules.

5. **Classification of Glycosidic Linkage**: The resulting bond is similar to an ether bond (ROR type linkage), where R represents the carbon chains of the sugar molecules and O represents the oxygen atom that connects them. Therefore, glycosidic linkage can be classified as an ether linkage.

6. **Conclusion**: Among the options provided (amide linkage, ester linkage, ether linkage, acetyl linkage), the correct classification for glycosidic linkage is **ether linkage**.

**Final Answer**: Glycosidic linkage is an **ether linkage** (Option 3).

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