Biocatalysis is defined as the use of natural substances that include enzymes from biological sources or whole cells to speed up chemical reactions. Enzymes have a pivotal role in the catalysis of hundreds of reactions that include the production of alcohols from fermentation and cheese by the breakdown of milk proteins. A biocatalyst is a substance (enzyme or hormone) that initiates or speeds up biochemical reactions. e.g.digestive enzymes like pepsin, trypsin, etc.
Biotransformation defines the chemical modification of chemicals such as nutrients, amino acids, toxins, and drugs in the body. It is also required to render non-polar compounds polar so that they are not reabsorbed in renal tubules and are expelled and it is a process by which a substance changes from one chemical to another by a chemical reaction inside the body. Metabolism or metabolic conversions are terms commonly used for the biotransformation process. The metabolism of a drug or toxin in a body is an example of biotransformation. The body typically assigns a foreign mixture by making it more water-soluble, to increase the rate of its elimination through the urine.