Glycosidic bond identification by linkage position and anomeric configuration

Steps:

• Locate the bond at position X, which connects the anomeric carbon (C1) of one monosaccharide to another in the polysaccharide chain.
• Assess the anomeric configuration: alpha if the OH group at C1 is below the ring plane in the Haworth projection.
• Identify the attachment point on the second monosaccharide: position 6 indicates linkage to the CH2OH group carbon.
• Confirm the bond as α-1,6 based on alpha orientation and C6 linkage in the diagram.

Why B is correct:

• α-1,6 glycosidic bonds form between C1 (alpha) of one glucose and C6 of another, creating branched structures like in glycogen, matching the diagram's configuration.

Why the others are wrong:

• A links C1 (alpha) to C4, forming linear chains like in starch, not branching at C6.
• C links C1 (beta) to C4, as in cellulose, with beta orientation not shown.
• D links C1 (beta) to C6, rare in polysaccharides and mismatches the alpha configuration.

Final answer: B