Henrik Kacser FRSE (22 September 1918 – 13 March 1995) was a Romanian-born biochemist and geneticist who worked in Britain in the 20th century. Kacser's achievements have been recognised by his election to the Royal Society of Edinburgh in 1990, by an honorary doctorate of the University of Bordeaux II in 1993. Early life Henrik Kacser was born in Câmpina, Romania, in 1918 to Olga and Soma Kacser, an engineer, both of Austro-Hungarian descent. The family moved to Berlin, where Henrik went to the Tretscher School. Before World War II, for educational reasons he moved to Belfast, Northern Ireland, where he did his undergraduate (BSc 1940, MSc 1942) and postgraduate work (PhD 1949) at the Queen's University of Belfast. There he studied chemistry, specialising in physical chemistry as a postgraduate student. He went to the University of Edinburgh in 1952 as a Nuffield Fellow under a scheme to introduce physical scientists into biology. This was to become the start of his work as a geneticist/biochemist. He earned the Diploma of Animal Genetics, and in 1955 he was appointed to the rank of Lecturer in the Department of Genetics at the University of Edinburgh. Areas of research In most of his research his original training in physical chemistry is quite evident, as he focused mainly on the physical/chemical aspects of biology. Much of his early work includes work on practical chemistry, kinetics of enzyme reactions and very little on genetics. His work in this early period attracted little attention, with even the most highly cited paper having only 52 citations by in 65 years. Between 1957 and 1973 he had only four publications, and it would have been easy to conclude that his career was over. However, that would have been completely wrong. Kacser's work falls into four distinct categories: 1. building a foundation in physical chemistry; 2. development of metabolic control analysis; 3. consolidation and 4. expansion. Only in the third phase of his career his expertise in genetics came to light when he set out to find experimental models to demonstrate the correctness of his paper on metabolic control analysis. The control of flux Kacser's paper with Jim Burns, The control of flux, later thoroughly revised to take account of changes in terminology, was a landmark paper for both authors. It described how the rates of metabolic pathways were affected by changes in the amounts or activities of pathway