Glycosidic bonds link carbohydrates in biomolecules

Steps:

• Recall glycosidic bonds form between sugar monomers or sugars and other molecules like proteins.
• Identify glycopeptides and glycoproteins contain glycosidic linkages between carbs and amino acids (O- or N-linked).
• Note glycolipids involve glycosidic bonds between carbs and lipids, but question focuses on peptide/ester contexts.
• Match choice A to bonds in glycopeptides/glycoproteins, excluding lipids.

Why A is correct:

• Glycosidic bonds in glycopeptides and glycoproteins are defined as covalent links between carbohydrate and peptide/protein chains, per biochemical nomenclature.

Why the others are wrong:

• B incorrectly includes glycolipids while limiting glycoproteins.
• C fragments and wrongly isolates glycolipids from glycopeptides.
• D excludes glycoproteins, omitting key protein-linked examples.

Final answer: A