Glycosidic linkage is actually an :

Glycosidic linkage is a type of bond found in carbohydrates, specifically in disaccharides and polysaccharides. It connects two monosaccharide units.

To understand its nature, recall that monosaccharides have hydroxyl groups (-OH) and an anomeric carbon (a carbon that was part of the carbonyl group in the open-chain form). When two monosaccharides react, the hydroxyl group of one monosaccharide attacks the anomeric carbon of another, leading to the loss of a water molecule (dehydration). This reaction forms a covalent bond.

The bond formed involves an oxygen atom that bridges two carbon atoms: one from the anomeric carbon of the first sugar and another from a carbon (usually C-4 or C-6) of the second sugar. This structure, where oxygen is linked to two carbon atoms, is characteristic of an ether functional group (C-O-C).

Now, comparing the options:

• Option A: Carbonyl bond refers to a carbon-oxygen double bond (C=O), present in aldehydes, ketones, etc. Glycosidic linkage does not have this.
• Option B: Ether bond is a bond with C-O-C linkage, which matches the description of glycosidic linkage.
• Option C: Ester bond is formed between a carboxylic acid and an alcohol (R-COO-R'), which is not the case here.
• Option D: Amide bond involves a carbonyl group linked to nitrogen (R-CONH-R'), found in proteins, not carbohydrates.

Thus, glycosidic linkage is an ether bond.

Hence, the correct answer is Option B.