11. A liver cell is undergoing gluconeogenesis. What would the effect be on the

Question

11. A liver cell is undergoing gluconeogenesis. What would the effect be on the rate of gluconeogenesis for each of the following? Explain your answer.

Increasing the concentration of acetyl Co-A

b) Decreasing the concentrations of AMP

c) Increasing the concentration of fructose-2,6-bisphosphate

d) Increasing the concentration of glutamate

e) Decreasing the concentration of biotin

11. A liver cell is undergoing gluconeogenesis. What would the effect be on the rate of gluconeogenesis for each of the following? Explain your answer. a) Increasing the concentration of acetyl Co-A b) Decreasing the concentrations of AMP c) Increasing the concentration of fructose-2,6-bisphosphate d) Increasing the concentration of glutamate e) Decreasing the concentration of biotin

Explanation / Answer

A liver cell is undergoing gluconeogenesis, the rate of gluconeogenesis is affected by:

1) Increasing the concentration of acetyl Co-A: It stimulates the enzyme pyruvate carboxylase which involves in the carboxylation of pyruvate to oxaloacetae. Thus it increases the rate of gluconeogenesis.

2) Decreasing the concentration of AMP : It stimulates phosphofructokinase that involves in conversion of fructose-6-phosphate to fructose1,6 biphosphate in glycolsis and inhibit the fuctose 1,6 biphosphatase that act reversibly in gluconeogenesis. So the rate of gluconeogenesis decreases.

3)  Increasing the concentration of fructose-2,6-bisphosphate : It act allosterically to site of enzymes  fuctose 1,6 biphosphatase and phosphofructokinase . High levels of fructose-2,6-bisphosphate allosterically activates the phosphofructokinase of glycolysis and decreases the rate of gluconeogenesis .

4) Increasing the concentration of glutamate : Glutamine is the main source of carbon atom in gluconeogenesis which converts after first deamination into glutamate which further undergo deamination to alpha-ketoglutarate and enters into further cycle. Thus it inhibits the gluconeogenesis.

5) Decreasing the concentration of biotin: Pyruvate carboxylase is referred as ABC enzyme (ATP, Biotin and CO2) that involve in conversion of pyruvate to PEP which is the initial step of gluconeogensis. So increase in the biotin concentration increases the activation of pyruvate carboxylase and thus increase the rate of gluconeogenesis.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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