Chapter 17: Glycolycis notes

Study Outline: Glycolysis 

I. Introduction 

• Definition of glycolysis 
• Importance of glycolysis in energy extraction from nutrients 

II. Overall Pathway of Glycolysis 

• Glycolysis as the first stage of glucose metabolism 
• Conversion of glucose to fructose-1,6-bisphosphate 
• Pyruvate as the end product 
• Different fates of pyruvate 

III. The Glycolytic Pathway 

• Each reaction catalyzed by a reaction-specific enzyme 
• Hydrolysis of ATP for glucose metabolism 
• ATP production in the beginning and later steps 
• Net gain of 2 ATP molecules for each glucose molecule broken down in glycolysis 

IV. The Reactions of Glycolysis 

• Step 6: Oxidation and phosphorylation of glyceraldehyde-3-phosphate 
• Step 7: Transfer of a phosphate group from 1,3-bisphosphoglycerate to ADP 
• Step 8: Isomerization of 3-phosphoglycerate to give 2-phosphoglycerate 
• Step 9: Dehydration of 2-phosphoglycerate to give phosphoenolpyruvate 
• Step 10: Transfer of a phosphate group from phosphoenolpyruvate to ADP to give pyruvate 

V. Conversion of Glucose to Glyceraldehyde-3-Phosphate 

• Step 1: Glucose phosphorylation to give glucose-6-phosphate 
• Reaction energy requirements and sources 
• Hexokinase as the catalyzing enzyme 
• Step 4: Splitting of fructose-1,6-bisphosphate into two 3-carbon fragments 
• Aldolase and its role in catalysis 
• Step 5: Conversion of dihydroxyacetone phosphate (DHAP) to glyceraldehyde-3-phosphate 

VI. Summary 

• Glycolysis pathway and key intermediate 
• Phosphofructokinase as allosterically controlled enzyme 

VII. Conclusion 

• Importance of understanding glycolysis in energy metabolism 
• Future directions for research and application