Maud Leonora Menten (March 20, 1879 – July 26, 1960) was one of the most versatile, innovative investigators in chemistry in the early part of the century. She graduated from the University of Toronto, receiving a B.A. in 1904 and a M.B. in medicine in 1907. Menten was appointed fellow at the Rockefeller Institute for Medical Research for the 1907-1908 year were she studied the effect if radium on tumors. She then returned to the University of Toronto where, in 1911, she became one of the first Canadian women to receive a medical doctorate. She subsequently worked as a demonstrator of physiology in Archibald Byron MacCallum's (1858-1934) laboratory at the University of Toronto. Then, in 1912 she joined Leonor Michaelis at the University of Berlin. It was the work there that was to give her eternal recognition – the Michaelis-Menten equation. This concept forever changed the study of biological reactions and helped to shape the field of biochemistry. The Michaelis-Menten equation gave scientists a way in which they could mathematically analyze their observations and descriptions of biological reactions. Not content to rest on her remarkable discovery, Menten co-devised what is now the standard method of isolating and describing protein behavior. She was finally promoted to full professor in 1949 when she was 70 years old, at the University of Pittsburgh School of Medicine in Pennsylvania. This was one year before her retirement from her position at Pittsburgh.