The renal system plays a crucial role in maintaining homeostasis by regulating fluid and electrolyte balance, removing waste products, and conserving essential substances through filtration, excretion, and reabsorption of various chemical species. Understanding the transport and transformation of these chemical species within the kidneys is essential for elucidating the mechanisms underlying various pathophysiological conditions caused by disruptions in various biophysical and biochemical processes, including species transport and chemical reactions. This section overviews the complex interaction between transport and reaction kinetics within the renal system, highlighting their significance in the context of renal diseases, particularly diabetic nephropathy (DN).