Enzymes are proteins that serve as catalysts in living cells, speeding up the rate of a certain chemical reaction. They allow metabolic processes, which are non-spontaneous chemical reactions that would otherwise take too long in the mild cellular environment, to occur quickly and in a controlled manner in live cells. Enzymes only act on the substrate or reactant that they were designed for. This gives living cells the ability to control when and where specific metabolic events occur. Enzymology is a branch of biology that studies enzymes, which are a type of protein. These proteins speed up specific chemical reactions in a biological system that are necessary for the organism's growth, development, adaptation, and survival. An enzyme's absence, accumulation, or failure has serious consequences for a living creature, some of which manifest as metabolic diseases. In the second part of the twentieth century, enzymology served as a critical link between chemistry and biology. A slew of new scientific difficulties is providing intriguing prospects for the field to thrive in the future.