Branches of Biology
Biochemistry is one of the crossover fields of chemistry. Biochemists have to understand both the living world and the chemical world. Even if you don't want to become a biochemist, you'll still have to understand atoms and molecules as a biologist.
Marcus was born in Montreal, Quebec, the son of Esther (née Cohen) and Myer Marcus. His interest in the sciences began at a young age. He excelled at mathematics at Baron Byng High School. He then studied at McGill University under Dr. Carl A. Winkler, who had studied under Cyril Hinshelwood at Oxford University. At McGill, Marcus took more math courses than an average chemistry student, which would later aid him in creating his theory on electron transfer. He earned B.Sc. in 1943 and a Ph.D. in 1946, both from McGill University. In 1958, Marcus became a naturalized citizen of the United States. After graduating, in 1946, he worked at the Polytechnic Institute of Brooklyn. In 1952, at the University of North Carolina, he developed Rice-Ramsperger-Kassel-Marcus theory by combining RRK theory with transition state theory. In 1964, he taught at the University of Illinois.
Calvin was born in St. Paul, Minnesota, the son of Elias Calvin and Rose Herwitz, Jewish immigrants from the Russian Empire. His father was born in Lithuania and his mother in Georgia As a small child Calvin's family moved to Detroit; he graduated from Central High School in 1928. Melvin Calvin earned his Bachelor of Science from the Michigan College of Mining and Technology in 1931 and his Ph.D. in chemistry from the University of Minnesota in 1935. He then spent the next four years doing postdoctoral work at the University of Manchester. He married Marie Genevieve Jemtegaard in 1942 and they had three children, two daughters and a son.
He was the pioneer scientist in study of cellular respiration, a biochemical pathway in cells for production of energy. He is best known for his discoveries of two important chemical reactions in the body, namely the urea cycle and the citric acid cycle. The latter, the key sequence of metabolic reactions that produces energy in cells, often eponymously known as the "Krebs cycle", earned him a Nobel Prize in Physiology or Medicine in 1953. With Hans Kornberg, he also discovered the glyoxylate cycle, which is a slight variation of the citric acid cycle found in plants, bacteria, protists, and fungi.
Krebs was born in Hildesheim, Germany, to Georg Krebs, an ear, nose, and throat surgeon, and Alma Krebs. He was the middle of three children, older sister Elisabeth and younger brother Wolfgang. He attended the famous old Gymnasium Andreanum in his home town. Before completing his secondary school education he was drafted in the Imperial German Army during World War I in September 1918. He was allowed to appear in an emergency higher school leaving certificate, which he passed in such a good grade that he suspected the examiners of being “unduly lenient and sympathetic”. The war ended after two months and his conscription ended. He decided to follow his father's profession and entered the University of Göttingen in December 1918 to study medicine.