Pentose Phosphate Pathway | Hexose Monophosphate Pathway | Metabolism

Pentose phosphate pathway takes place in the cytosol. The main goal of the pathway is to synthesize ribose-5-phosphate to be used for nucleotide synthesis and reductive bioequivalent like NADPH. There are two phases of the pathway, irreversible oxidative and reversible non-oxidative reactions. In irreversible oxidative reaction, glucose-6-phosphate is converted into ribulose-5-phosphate while generating 2 molecules of NADPH and CO2. NADH is important for fatty acid synthesis, steroid synthesis and for oxidative stress. In the reversible non-oxidative reaction, ribulose-5-phosphate is converted to ribose-5-phosphate, which can then be used for nucleotide synthesis. If the demand for NADHP is higher then ribulose-5-phosphate can convert into xylulose-5-phosphate. Through series of reactions, 1 ribose-5-phosphate and 2 xylulose-5-phosphate are converted to glycolytic intermediates such as 2 fructose-6-phosphate and 1 glyceraldyhyde-3-phosphate. These intermediates are then channeled back to glycolysis pathway and through gluconeogenesis, they are converted back to glucose-6-phosphate to re-enter into pentose phosphate pathway to synthesise more NADHP. The following topics are covered in this lesson, 1. What is pentose phosphate pathway? 2. What are the two phases of pentose phosphate pathway? 3. What is irreversible oxidative reaction 4. What is reversible non-oxidative reaction? 5. What is NADHP and why is it important? 6. Why is pentose phosphate pathway important? 7. How is glucose-6-phosphate converted to fructose-6-phosphate and glyceraldehyde-3-phosphate? For gluconeogenesis,    • Gluconeogenesis | Pathway Overview | Gluco...   Fro glycolysis,    • Glycolysis | Carbohydrate Metabolism | Bio...