Glycolysis is the metabolic pathway that converts glucose into pyruvate, generating ATP and NADH in the process. Gluconeogenesis, on the other hand, is the process of synthesizing glucose from non-carbohydrate precursors, such as pyruvate, lactate, glycerol, and certain amino acids. Both pathways occur in the cytoplasm of cells, but glycolysis is a catabolic process breaking down molecules , while gluconeogenesis is an anabolic process building molecules .The net chemical reaction of glycolysis is as follows:Glucose + 2 NAD+ + 2 ADP + 2 Pi 2 Pyruvate + 2 NADH + 2 H+ + 2 ATP + 2 H2OGluconeogenesis is essentially the reverse of glycolysis, but it is not an exact reversal. Instead, it bypasses the three irreversible steps of glycolysis with four distinct reactions to ensure that glucose synthesis is thermodynamically favorable.The net chemical reaction of gluconeogenesis is as follows:2 Pyruvate + 2 NADH + 2 H+ + 4 ATP + 2 GTP + 6 H2O Glucose + 2 NAD+ + 4 ADP + 2 GDP + 6 PiKey enzymes involved in glycolysis:1. Hexokinase or glucokinase in the liver - phosphorylates glucose to glucose-6-phosphate.2. Phosphofructokinase-1 PFK-1 - phosphorylates fructose-6-phosphate to fructose-1,6-bisphosphate.3. Pyruvate kinase - converts phosphoenolpyruvate PEP to pyruvate, generating ATP.Key enzymes involved in gluconeogenesis:1. Pyruvate carboxylase - converts pyruvate to oxaloacetate.2. Phosphoenolpyruvate carboxykinase PEPCK - converts oxaloacetate to phosphoenolpyruvate PEP .3. Fructose-1,6-bisphosphatase FBPase-1 - hydrolyzes fructose-1,6-bisphosphate to fructose-6-phosphate.4. Glucose-6-phosphatase - hydrolyzes glucose-6-phosphate to glucose only in the liver and kidneys .In summary, glycolysis and gluconeogenesis are two metabolic pathways with opposing functions. Glycolysis breaks down glucose to generate ATP and NADH, while gluconeogenesis synthesizes glucose from non-carbohydrate precursors. Although the two pathways share several enzymatic steps, they differ in their net chemical reactions and key regulatory enzymes.