HNF 461 Lecture 5 Outline of Last Lecture I Hexosemonophosphate Shunt Pentose Phosphate Pathway a Oxidative Stage b Nonoxidative Stage II Glycogenesis a Glucose Phosphatase b Glycogen Synthase III Glycogen Branching IV Fatty Acid Synthesis Outline of Current Lecture I Glycemic Index II Control of Blood Glucose III Insulin and Glucagon IV Glycogenolysis a Glycogen Phosphorylase b cAMP Current Lecture Glycemic Index Insulin and Glucagon Action and Glycogenolysis 1 Glycemic Index Measures the ability to increase blood glucose levels in reference to pure glucose acts as the standard a GI area under the curve area under the pure glucose curve b Provides guidelines on what foods to eat important for diabetes c Determining Food s Glycemic Index i Rate of glucose absorption into the intestine ii Rate of glucose transport from blood to tissues 2 Control of Blood Glucose a Liver glycogenolysis and gluconeogenesis 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 b Pancreas secretes insulin from beta cells and glucagon from alpha cells c Hormones orchestrate how organs use the glucose this is why organs function differently than others 3 Insulin and Glucagon a Bind to cell receptors which sends signals to the cells and cause reactions within the cells b Insulin causes dephosphorylation of enzymes c Glucagon causes phosphorylation of enzymes Insulin Glucagon Glycogenolysis breaks glycogen into glucose Inhibits Activates Glycogenesis builds glycogen from glucose Activates Inhibits Glycolysis Removes glucose from blood Activates Inhibits Gluconeogenesis Inhibits Activates 4 Glycogenolysis Glycogen Metabolism a Low glucose glucagon is released from pancreas b Glucagon activates protein kinases which activate glycogenolysis c Glycogen Phosphorylase activates cleave of glucose molecules off glycogen molecule A cleaved glycogen forms glucose 6 P used for glycolysis or if in the liver is released as glucose i Glycogen Phosphylase in the liver glucagon epinephrine trigger cAMP secondary messenger cAMP activates phosphorylation of glycogen phosphorylase kinase When activated glycogen phosphorylase kinase releases glucose ii In the muscles when exercising AMP builds up in the muscles AMP can bypass phosphorylation step and activates the enzyme to release glucose
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