Glycolysis: Metabolic Pathway and Regulation

Overview of Glycolysis

• Glycolysis is a metabolic pathway that converts glucose (a 6-carbon sugar) into pyruvate (a 3-carbon molecule)
• Occurs in the cytosol of cells and is the first step in cellular respiration
• Does not require oxygen (anaerobic process)

Steps of Glycolysis

1. Glucose phosphorylation: Glucose is converted into glucose-6-phosphate using one ATP molecule
2. Phosphoglucose isomerase: Glucose-6-phosphate is converted into fructose-6-phosphate
3. Aldolase: Fructose-6-phosphate is converted into fructose-1,6-bisphosphate
4. Triosephosphate isomerase: Fructose-1,6-bisphosphate is converted into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate
5. Glyceraldehyde-3-phosphate dehydrogenase: Glyceraldehyde-3-phosphate is converted into 1,3-bisphosphoglycerate
6. Phosphoglycerate kinase: 1,3-Bisphosphoglycerate is converted into 3-phosphoglycerate and ATP
7. Phosphoglycerate mutase: 3-Phosphoglycerate is converted into 2-phosphoglycerate
8. Enolase: 2-Phosphoglycerate is converted into enolpyruvate
9. Pyruvate kinase: Enolpyruvate is converted into pyruvate and ATP

Net Gain of Glycolysis

• 2 ATP molecules are produced
• 2 NADH molecules are produced
• Pyruvate is produced, which can be used in the citric acid cycle or converted into lactate

Regulation of Glycolysis

• Allosteric regulation by ATP, ADP, and AMP
• Feedback inhibition by ATP and NADH
• Activation by fructose-2,6-bisphosphate and insulin

Learn about the steps of glycolysis, a crucial metabolic pathway that converts glucose into pyruvate. Understand the regulation of glycolysis, including allosteric regulation and feedback inhibition. Test your knowledge of this fundamental process in cellular respiration.