Question

What is the role of glycogenin in the structure and synthesis of glycogen?

a. Glycogenin is a protein that helps in the synthesis of new glycogen primer molecules. The protein to which glycogen is attached, glycosylates itself and then extends the carbohydrate chain until the glucosyl chain is long enough to serve as a substrate for glycogen synthase.
b. Glucose 6-Phosphate only located in liver and kidney . In muscle, glycogen used to generate ATP
c. Liver glycogen is the first and immediate source of glucose for the maintenance of blood glucose levels
d. specific enzyme "phosphrylases"

Answer 1

Glycogenin serves as a primer for glycogen synthesis, attaching the first glucose molecules to itself, thus enabling glycogen synthase to extend the glucose chain and form a highly branched, efficient energy storage molecule.

Step-by-step explanation:

The role of glycogenin in the structure and synthesis of glycogen is fundamental. Glycogenin is a protein enzyme that initiates the formation of glycogen by attaching the first few glucose molecules to itself, thereby acting as a primer. After this initial step, glycogen synthase extends the chain by forming α-1→4 glycosidic linkages between glucose units. This action creates a linear chain which is then further branched by a branching enzyme, creating a structure that is highly branched and efficient for energy storage. Therefore, glycogenin does not merely assist in the synthesis, but it is essential for starting the glycogen synthesis process, and without it, glycogen synthase cannot begin its work.

Glycogenin plays a crucial role in the structure and synthesis of glycogen. It acts as a protein primer for glycogen synthesis by catalyzing the attachment of the first few glucose molecules to itself. This forms a glycogen primer, which is then extended by glycogen synthase to form a linear chain of glucose residues. Eventually, branching enzyme adds branches to the glycogen chain.