 One of the most prolific of these modern biochemists was Hans Krebs who made huge contributions to the study of metabolism.He discovered the urea cycle and later, working with Hans Kornberg, the citric acid cycle and the glyoxylate cycle.Modern biochemical research has been greatly aided by the development of new techniques such as chromatography, X-ray diffraction, NMR spectroscopy, radioisotopic labelling, electron microscopy and molecular dynamics simulations.