Question: Assume you hypothesize that an animal with a mutation that affects conversion of the b form of glycogen synthase to the a form could not produce glycogen at functional levels. Your friend disagrees and believes that the animal would produce glycogen at functional levels. What good reason could your friend give for this guess? Select the best answer.

1. Insulin would inhibit glycogen synthase kinase.

2. The b form is always active, regardless of covalent modification.

3. The b form is inactive, and the organism cannot synthesize glycogen.

4. Insulin would allosterically activate the normally inactive b form of glycogen synthase.

5. Glucose 6-phosphate activation of the b form would stimulate glycogen synthesis.