Biochemistry is the study of the molecular basis of the chemical processes that occur in living organisms. It has applications in developing pharmaceuticals to treat diseases, all of which have a molecular component, and explaining changes in pH of biological fluids. Biochemistry studies enzymes, hormones, proteins, and cell interactions through analysis of biological fluids like blood, urine, tissues, and their components. Clinical laboratory tests using biochemistry help prevent, diagnose, and treat disease by evaluating factors like immune response, endocrine function, cancer treatment response, and nutritional status.