ABSTRACT

During the 1950s, considerable interest centered on the pathway of carbohydrate synthesis in liver tissue from noncarbohydrate precursors such as lactate and pyruvate, i.e., the process of gluconeogenesis was, in effect, a reversal of glycolysis; it was appreciated that the enzymic mechanism could not, for thermodynamic reasons, be a straightforward reversal of glycolysis. Krebs and Kornberg 476 pointed out that all but three steps of glycolysis were, in fact, readily reversed, but at these three loci, major energy barriers occur, viz.,   Glucose + ATP → GIucose,6-Phosphate + ADP                     ( 1 )     https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781351076142/b0676825-6621-4992-85ea-c12eb930e310/content/math1.tif"/>   Fruc t o s e , 6 -Phosphate + ATP → Fructose,l-6-Diphosphate + ADP                           ( 2 ) ⁢     https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781351076142/b0676825-6621-4992-85ea-c12eb930e310/content/math2.tif"/>   Phosphopyruvate + ADP → Pyruvate + ATP                                 ( 3 ) ⁢     https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781351076142/b0676825-6621-4992-85ea-c12eb930e310/content/math3.tif"/>