NS 3310 1st Edition Lecture 9Outline of Past LectureI. InsulinII. Integrated MetabolismOutline of Current LectureI. Glycogenesis and Glycogenolysis II. GlycolysisIII. GluconeogenesisIV. Pentose Phosphate PathwayCurrent LectureI. Glycogenesis and Glycogenolysis- Glycogenesis is the conversion of glucose to glycogen-Glucose gets into the cell, is converted to G-6-P, and then G-1-P. G-1-P is converted to glycogen- Glycogenolysis is the breakdown of glycogen to glucose and the regulation of phosphorylate-The enzyme GP cuts off the end of glucose residue and adds a phosphate group, generating G-1-P which is converted to G-6-P which is then used in glycolysis II. GlycolysisThese 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.- Glycolysis is the degradation of glucose to pyruvate-Provides substrates for TCA cycle that generates a lot of ATP and it provides intermediates for other metabolism pathways-The key enzymes are hexokinase and phosphofructokinase - Fructose is phosphorylated and metabolized mainly by the liver, whereas glucose is by alltissues with only 30-40% by the liver -Fructose is phosphorylated just like glucose and galactose by fructokinase and it generates F-1-P. It breaks into two and feeds into the glycolysis pathway -If there is a lot of fructose, it leads to the formation of triglycerides because ATP and citrate cannot regulate this pathway so it keeps going -Fructose metabolism is different from glucose. Fructose-1-phosphate feeds into glycolysis pathway and generates ATP and citrate. Citrate is used to make fatty acids. ATPor citrate is end product- regulates glycolysis or inhibits glycolysis by inhibiting PFK-1. Citrate marks energy excess or high energy. The outcome of high energy is to stop making glucose and store as glycogen through this ATP/citrate mediating of PFK-1III. Gluconeogenesis- Gluconeogenesis is the synthesis of glucose from non-carbohydrate sources- It is the reversal of glycolytic pathway and utilizes lactate- Hepatic gluconeogenesis: synthesis of glucose from non-hexose precursors (lactate, pyruvate, alanine, glycerol); occurs primarily in liverIV. Pentose Phosphate Pathway- First phosphorylation is at 6-P- When committed to make glycogen converted to G-1-P- Usually converted to G-6-P which can convert to PPP pathway- PPP generates NADPH and ribose. Ribose is needed for nucleotide synthesis and NADPH is used for a lot of important anabolic
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