Biotransformation is an essential process for life driven by chemical reactions inside the human body, which involves the conversion of one type of substance into a different one. As the driving force of metabolism, it enables nutrients to be converted into substances that are healthy for the body, pharmaceutical drugs to be converted into active components that treat certain conditions, and for toxic substances to be broken down into less-toxic compounds before they can be eliminated. Biotransformation occurs most often inside the liver, but it also occurs in the kidneys, lungs, skin, and intestines.
The processes of biotransformation are enabled by the continuous array of chemical reactions that occur in the body. In the majority of cases, such processes are triggered by enzymes, which act as catalysts for biochemical reactions. Important reactions include those that process sugar. Health conditions that affect the ability of certain enzymes to perform the required reaction or problems that lead to deficiencies of those enzymes can lead to birth defects, neurological deficiencies, and a variety of diseases.
Enzymes interact in differing and complex ways. Some have an effect on just a single chemical reaction, while others trigger reactions on molecules with certain structures, such as amino, phosphate, or methyl groups. Others target the structural chemical bond no matter what kinds of molecules are present. Metabolic chemical processes are broken down into the type of biotransformation phase.
Phase I processes, such as oxidation and hydrolysis, interact with specific toxicants. These toxicants can then either be directly eliminated or undergo further conversion. Phase II biotransformations act on substances that have undergone the first phase and which have been converted to an intermediate state containing hydroxyl, carboxyl, amino, or other reactive chemical groups. Another molecule is added to the substance to make it more water-soluble and easier to eliminate from the body. This kind of reaction is important in the processing and excretion of glucose.
Biotransformation can be heavily affected by dosage, which is influenced by what a particular substance is transformed into and by how much of the catalyst is used up in processing a specific amount of it. Age also has an impact because young and old people have slower metabolic capabilities. Nutrition, diseases, the presence of chemicals that affect certain enzymes, and genetics also have significant effects on biotransformation.