Organic Chemistry MCAT Practice Exam

What type of glycosidic bond is primarily found in glycogen?

1. Beta-1,4-glycosidic bonds

2. Alpha-1,6-glycosidic bonds

3. Alpha-1,4-glycosidic bonds

4. Gamma-1,3-glycosidic bonds

The correct answer is: Alpha-1,4-glycosidic bonds

Glycogen, a polysaccharide that serves as a primary energy storage form in animals, consists of glucose units linked together. The structure of glycogen primarily features alpha-1,4-glycosidic bonds, which connect the glucose monomers in a linear fashion. This type of linkage allows for the formation of long chains of glucose. In addition to these linear chains, glycogen also contains branching points that are formed by alpha-1,6-glycosidic bonds. These branch points occur approximately every 8 to 12 glucose units, creating a highly branched structure that is essential for the rapid release of glucose when needed. Overall, the key characteristic of glycogen is its predominance of alpha-1,4-glycosidic bonds, which form the backbone of the polysaccharide, while the alpha-1,6-glycosidic bonds serve merely as branches. This unique structure allows glycogen to be efficiently mobilized and quickly utilized for energy when the body requires it.