The activity of isocitrate dehydrogenase in E. coli is regulated by the covalent attachment of a phosphate group, which inactivates the enzyme. When acetate is the food source for a culture of E. coli, isocitrate dehydrogenase is phosphorylated. However, when glucose is added to the culture, the phosphate group is removed from isocitrate dehydrogenase. These observations indicate that acetate metabolism proceeds through the citric acid cycle * , while glucose metabolism proceeds through the gluconeogenesis pathway

The activity of isocitrate dehydrogenase in E. coli is regulated by the covalent attachment of a phosphate group, which inactivates the enzyme. When acetate is the food source for a culture of E. coli, isocitrate dehydrogenase is phosphorylated. However, when glucose is added to the culture, the phosphate group is removed from isocitrate dehydrogenase. These observations indicate that acetate metabolism proceeds through the citric acid cycle * , while glucose metabolism proceeds through the gluconeogenesis pathway

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter23: Fatty Acid Catabolism

Section: Chapter Questions

Problem 21P: Using the ActiveModel for enoyl-CoA dehydratase, give an example of a case in which conserved...

See similar textbooks

Similar questions

Demerol (meperidine) is a drug used to relieve moderate to severe pain through inhibition of theNADH dehydrogenase complex. Explain why this drug does not completely abolish oxidative phosphorylation.
Von Gierke’s disease is also known as glycogen storage disease type I. Patients with von Gierke’s disease lackglucose 6-phosphatase activity. Two prominent symptoms of this disorder are fasting hypoglycemia and lactic acidosis (elevated lactate levels in the blood), especially during strenuous exercise. Explain why these symptoms occur. What chemical reaction does this enzyme catalyze? Which pathways involve this enzyme? Lacking thisthe enzyme will cause impairment of which pathways?• Pls consider what pathways are affected by Von Gierke’s disease. Include in your explanation involving Cori’s cycle. can you please do not write by your hand? I mean computer if you can. thank you
Von Gierke’s disease is also known as glycogen storage disease type I. Patients with von Gierke’s disease lackglucose 6-phosphatase activity. Two prominent symptoms of this disorder are fasting hypoglycemia and lactic acidosis (elevated lactate levels in the blood), especially during strenuous exercise. Explain why these symptoms occur. What chemical reaction does this enzyme catalyze? Which pathways involve this enzyme? Lacking thisenzyme will cause impairment of which pathways?• Pls consider what pathways are affected by Von Gierke’s disease. Include in your explanation involving the Cori’s cycle.
When the identical subunits of chicken liver fatty acid synthase are dissociated in vitro, all of the activities can be detected in the separated subunits except for the β-ketoacyl synthase reaction and the overall synthesis of palmitate. Explain these observations.
Why Alpha-Ketoglutarate dehydrogenase (a-KGDH) called deficiency? What are the probable causes? Explain.
Because of the position of arsenic in the periodic table, arsenate (AsO43- ) is chemically similar to inorganic phosphate and is used by phosphaterequiring enzymes as an alternative substrate. Organic arsenates are quite unstable, however, and spontaneously hydrolyze. Arsenate is known to inhibit ATP production in glycolysis. Identify the target enzyme, and explain the mechanism of inhibition.
What is alpha keto glutarate dehydrogenase complex?. explain very briefly.
, which indicates AG for each glycolytic reac- tion under intracellular conditions. Assume that glyceraldehyde-3- phosphate dehydrogenase was inhibited with iodoacetic acid. Which glycolytic intermediate would you expect to accumulate most rapidly, and why?
Hexokinase catalyzes the first step of glycolysis, in which glucose is phosphorylated to form glucose‑6‑phosphate. Give two reasons why a Mg2+ cation is required to facilitate this reaction.
A sample of glycogen from a patient with liver disease is incubated with orthophosphate, phosphorylase, the transferase, and the debranching enzyme ( α -1,6- glucosidase). The ratio of glucose 1- phosphate to glucose formed in this mixture is 100. What is the most likely enzymatic deficiency in this patient?
Isocitrate labeled with 14C at positions 2 and 5 was isolated from cultured liver cells administered [methyl-14C pyruvate] and enough malonate to completely inhibit succinate dehydrogenase. Explain how this can happen.
A solution of the enzyme hexokinase incubated at 45 °C lost 50% of its activity in 12 min, but when incubated at 45 °C in the presence of a very large concentration of one of its substrates, it lost only 3% of its activity in 12 min. Suggest why thermal denaturation of hexokinase was retarded in the presence of one of its substrates. It is impossible for this result to be true. OA. Adding the substrate increases the weak forces that stabilize the enzyme. OB. The high concentration of substrate forms a barrier around the hexokinase. D. Adding the substrate results in protective covalent bonding.