Answer to Question #5084 in Biochemistry for saif

Question

What is the metabolic significance of the following observations? (1) Only the liver form of
pyruvate kinase is inhibited by alanine, and (2) only gluconeogenic tissues contain appreciable levels of
glucose-6-phosphatase?

Answer 1

1)Synthesis of glucose from pyruvate that is formed by deamination of alanine takes part in the liver (one of types of gluconeogenesis). Liver form of
pyruvate kinase take part in this prouces (conversion of pyruvate to
phosphoenolpyruvate). Therefore, liver form of pyruvate kinase is regulated
allosterically by alanine.




2)Because glucose are formed from molecules of other organic compounds in glukoneogenic tissues, and glucose-6-phosphatase is one of the key enzymes of
such glucose synthesis.It turns glucose-6-phosphate into glucose.