Peroxidase is an enzyme found in many organisms, from plant to humans. The function of peroxidase is to break down hydrogen peroxide, which is a toxin produced as a byproduct when oxygen is produced during respiration. Myeloperoxidase is a protein found in neutrophils and catalyzes lipid peroxidation involved in immune defense. The overproduction of myeloperoxidase has been found to function as a mediator for tissue damage in inflammatory diseases. A- Identify two examples of environmental factors that may impact salivary peroxidase activity. Describe how each of the environmental factors would affect the reaction rate of the enzyme.

B- Predict the how researchers can use myeloperoxidase activity as oxidative stress biomarkers in patients with rheumatoid arthritis. Provide reasoning to justify your prediction.