What is PDK enzyme?
Pyruvate dehydrogenase kinase (also pyruvate dehydrogenase complex kinase, PDC kinase, or PDK; EC 2.7. 11.2) is a kinase enzyme which acts to inactivate the enzyme pyruvate dehydrogenase by phosphorylating it using ATP.
Is PDC reversible?
PDC activity is regulated via reversible phosphorylation of three serine residues on the pyruvate dehydrogenase (PDH) E1α subunit.
Where is PDC most active in the cell?
mitochondria
PDC is a large multi-enzyme complex located within the matrix compartment of mitochondria, and links glycolysis to the tricarboxylic acid cycle by catalyzing the irreversible oxidative decarboxylation of pyruvate, which leads to the generation of CO2, NADH, and acetyl-CoA.
Why does insulin activate pyruvate dehydrogenase?
Insulin indirectly stimulates glucose oxidation via increasing glucose uptake and subsequent glycolysis that increases pyruvate supply for mitochondrial glucose oxidation by the pyruvate dehydrogenase (PDH) complex, the rate-limiting enzyme of glucose oxidation.
What is the end result of the PDC reaction?
What is the end result of the PDC reaction? Acetyl CoA containing a high energy thioester bond to be fed into the citric acid cycle.
How is PDC regulated?
The PDC is regulated by covalent modification through the action of a specific kinase and phosphatase; the kinase and phosphatase are regulated by changes in NADH, acetyl-CoA, pyruvate, and insulin.
Why is pyruvate converted to Acetyl-CoA?
After glycolysis, pyruvate is converted into acetyl CoA in order to enter the citric acid cycle.
What produces pyruvate?
glycolysis
Pyruvate is produced by glycolysis in the cytoplasm, but pyruvate oxidation takes place in the mitochondrial matrix (in eukaryotes). So, before the chemical reactions can begin, pyruvate must enter the mitochondrion, crossing its inner membrane and arriving at the matrix.
Where does oxidative decarboxylation occur?
mitochondrial matrix
During cellular respiration, oxidative decarboxylation occurs in the mitochondrial matrix. Pyruvate is converted to acetyl CoA. The enzyme pyruvate dehydrogenase catalyses the reaction.
