Alternative pathways for glucose metabolism

Abstract

Glucose metabolism through glycolysis is one of the most fundamental biochemical processes that take place in every living cell. Different enzymes involved in glycolysis are well conserved among different organisms. Pyruvic acid is the end product of glycolysis that either enters into the mitochondria to participate in Krebs cycle to generate ATPs or under anaerobic condition get converted into lactate. However, in some tissues pyruvate may convert back to carbohydrates (such as glucose) through gluconeogenesis. Parallel to these basic pathways of glucose metabolism, other alternative pathways also exist to perform specialized functions of cells. Three such major alternative pathways are Pentose phosphate pathway, Glucuronic acid pathway and Entner-Doudoroff pathway. Pentose phosphate pathway is an essential and universal pathway which converts glucose 6-phosphate to ribose 5- phosphate that serves as sole source of pentose sugar for DNA synthesis. Glucose 6-phosphate also serves as primary molecule that enters into Gluconic acid pathway to generate UDP-gluconate which helps in detoxification of foreign chemicals and synthesis of Mucopolysaccharides. Entner-Doudoroff pathway also converts glucose into pyruvate and acts as alternative to glycolysis in lower organisms. These three pathways also produces NADPH/H+ which play significant role in fatty acid metabolism and steroid synthesis. ? 2017 Nova Science Publishers, Inc. All rights reserved.