Question

Suppose a researcher introduces a mutation into the glucosidase domain of the mammalian glycogen debranching enzyme. The mutation inhibits the activity of the glucosidase but does not affect the other functions of the enzyme. The researcher then introduces the mutated enzyme into mammalian cells that do not express wild type glycogen debranching enzyme. Predict the effect of the mutation on glycogen metabolism. a. linear glycogen chains with minimal branching b. glycogen molecules with branches containing five or more glucose residues c. glycogen molecules with branches containing a single glucose residue d. glycogen molecules with branches containing four glucose residues

Answer 1

Answer:

c. glycogen molecules with branches containing a single glucose residue

Explanation:

The mutation inhibits the activity of the glucosidase but does not affect the other functions of the enzyme. The researcher then introduces the mutated enzyme into mammalian cells that do not express wild type glycogen debranching enzyme because glycogen molecules with branches containing a single glucose residue (single glucose molecule linked by alpha 1,6 linkage due to mutation in glucosidase activity of debranching enzyme).