Answer:
Due to difference in their products.
Step-by-step explanation:
Glycolysis and gluconeogenesis are not exact reverse to each other because in glycolysis, glucose is converted into pyruvate, adenosine triphosphate (ATP), NADH, protons i.e. hydrogen ions and water whereas in gluconeogenesis, pyruvate is converted into glucose and glycogen. So due to the formation of different products of each process we can say that glycolysis is not exact reverse of gluconeogenesis.