Glycolysis

• Insulin is a hormone that promotes glycolysis
• Glucagon is a hormone that will decrease glycolysis
• Glycolysis is anaerobic (in terms of oxygen), catabolic, oxidative and happens in cytosol
• ARCO is the abbreviation of anabolic/catabolic
• 1st five reactions of glycolysis will result in investment of 2 ATP and will have negative G
• Last 5 reactions of glycolysis result in production of 4 ATP, 2 NADH and 2 pyruvate (with net of 2 ATP as a result)
• 2NADH from glycolysis will go to electron transport chain
• 1st step of glycolysis: alpha-glucose -> glucose-6-phosphate by the enzyme hexokinase. This is one-way reaction. Requires 1 ATP
• 2nd step of glycolysis: glucose-6-phosphate -> fructose-6-phosphate by the enzyme phosphoglucose isomerase. This is a reversible reaction.
• 3d step of glycolysis: fructose-6-phosphate -> fructose-1,6-bisphoshate by enzyme phosphofructokinase-1. This is a one-way reaction. Requires 1 ATP
• 4th step fo glycolysis: fructose-1,6-bisphospate -> G3P + DHAP (abbreviations only) by enzyme aldolase. This is a reversible reaction
• 5th step of glycolysis: DHAP -> G3P by enzyme triose phosphate isomerase. This is a reversible reaction.
• 6th step of glycolysis: G3P -> 1,3-bisphosphoglycerate by enzyme glyceraldehyde-3-phosphate dehydrogenase. This is a reversible and redox reaction, which requires NAD+ to be reduced
• 7th step of glycolysis: 1,3-bisphosphoglycerate -> 3-phosphoglycerate by enzyme phosphoglycerate kinase. This is a reversible reaction. It produces ATP
• 8th step of glycolysis: 3-phosphoglycerate -> 2-phosphoglycerate by enzyme phosphoglycerate mutase.
• 9th step of glycolysis: 2-phosphoglycerate -> phosphoenolpyruvate by enzyme enolase. This is a reversible reaction. It produces H2O
• 10th step of glycolysis: phosphoenolpyruvate -> pyruvate by enzyme pyruvate kinase. This is a one-way reaction. It produces ATP
• Glucokinase works in liver and pancreatic Beta-cells
• Hexokinase has lower Km and lower Vmax than glucokinase
• The redox step of glycolysis utilized enzyme glyceraldehyde-3-phosphate dehydrogenase
• ATP producing steps of glycolysis have those with enzymes phosphoglycerate kinase and pyruvate kinase
• ATP consuming steps of glycolysis are enzymes hexokinase and phosphofructokinase-1
• Hexokinase is negatively inhibited by glucose-6-phosphate