Glycogen synthesis and breakdown are regulated primarily at the hormonal level.

Question

Glycogen synthesis and breakdown are regulated primarily at the hormonal level. However, important nonhormonal mechanisms also control the rates of synthesis and mobilization.

Part A

Describe these nonhormonal regulatory processes.

Match the words in the left column to the appropriate blanks in the sentences on the right.

glucose-1-phosphate Glycogen breakdown is under nonhormonal as well as hormonal control. Recall that phosphorylase b is relatively inactive, existing primarily in s T state. This form of the enzyme is activated allosterically by 5 (but not by hormonal CAMP). This activation does not usually occur in the cell because ATP, which is far more abundant and does not ADP activate phosphorylase b, competes with for binding to the enzyme. However, under energy-deprived glucose-6-phosphate conditions AMP may accumulate at the expense of ATP breakdown binding shifts the conformational AMP equilibrium of phosphorylase b to the more active Rstate. ATP and signs of adequate energy status, shift the equilibrium of phosphorylase b back to the less active T state. ATP nonhormonal U Once glycogen phosphorylase bis phosphorylated to its more active a state, it exists primarily in the R form and is unresponsive to most metabolite effectors. However, glucose and act synergistically on phosphorylase a, shifting its equilibrium slightly back toward the Tstate. In the T state, the phosphoserine side chains are more accessible to phosphoprotein phosphatase 1, so that the T state is more readily dephosphorylated than the R state. The mechanism, which does not involve a metabolic cascade, stimulates glycogenolysis in response to a low-energy charge, whereas the mechanism predominates when the need is to rapidly augment energy generation

Explanation / Answer

The appropriate answers are as follows

1. AMP

2. Adp

3. Atp

4. Glucose-6-phosphate

5. Glucose-1-phosphate

6. non hormonal

7. hormonal

Related Questions

Navigate

• Browse (All)
• Browse G
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.