Pentose Phosphate Cycle an overview ScienceDirect Topics Explain how Inactivity or absence of Glucose 6 phosphate dehydrogenase ; a rate limiting enzyme in the Pentose phosphate pathway could lead to oxidative stress.* The NADPH Link between the Renin Angiotensin System and the Antioxidant Mechanisms in Dopaminergic Neurons Glucose metabolism begins with its transport into cells via GLUT transporters, where it is phosphorylated to glucose 6 phosphate (Glucose 6 P). This molecule can enter various pathways, including the pentose phosphate pathway or hexosamine biosynthesis. 6.3: The Pentose Phosphate Pathway Biology LibreTexts