Reactions favor the formation of products under the reaction's conditions.
They occur without any external energy input.
Example- rusting of iron, radioisotope decay, etc.
Metabolic pathways:
They are a series of chemical reactions in living organisms.
They are essential for the survival of organisms.
Examples- Glycolysis, Gluconeogenesis, etc.
Metabolic pathways are not spontaneous and are regulated by different enzymes. That is, they do not occur suddenly or in an uninhibited manner.
An example of enzyme regulation of a metabolic pathway is glycolysis.
Hexokinase, phosphofructokinase, and pyruvate kinase are the most important enzymes that regulate the rate of glycolysis. It helps in the conversion of one glucose molecule into two pyruvate molecules.