MCB 450 1st Edition Lecture 16 Outline of Last Lecture I Glycolysis a First phase Reactions 1 5 no ATP generated b Second Phase Reactions 6 10 generation of ATP II Feeder pathway to glycolysis other sugars can also enter the glycolytic pathway III Regulation of glycolysis IV Glucose transporters V Fate of pyruvate under anaerobic conditions a In yeast Alcohol fermentation b In other microorganisms and exercising muscle Lactic acid fermentation VI Hypoxia Inducible Factor Outline of Current Lecture I Glucose can be synthesized from noncarbohydrate precursors II Gluconeogenesis and glycolysis are reciprocally regulated III The Cori cycle IV Purpose of the Pentose Phosphate Pathway PPP V Oxidative phase VI Nonoxidative phase VII Balancing the cellular needs for ATP NADPH and ribose 5 P Current Lecture The Liver Regulates Blood Sugar Levels Gluconeogenesis precursors such as glycerol amino acids and lactate are converted to glucose o Takes place in the liver Gluconeogenesis in the liver and kidney helps to maintain the glucose level in the blood from which it can be extracted by the brain and muscle to meet their metabolic demands In some ways Gluconeogenesis is the reverse of Glycolysis But is not a complete reversal Why Several reactions must differ because the equilibrium of glycolysis favors pyruvate formation The delta G for the reaction is not as favorable and requires ATP Pyruvate carboxylase requires the vitamin biotin as a coenzyme Biotin a covalently attached prosthetic group that serves as a carrier of activated CO 2 These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Biotin is attached to pyruvate carboxylase by a long flexible chain It is not carboxylated unless acetyl CoA is bound to the enzyme The domain structure of the bifunctional regulatory enzyme phosphofructokinase 2 PF2 fructose 2 6 bisphosphatase A single polypeptide chain Contains an N terminal regulatory domain followed by a kinase domain and a phosphate domain
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