He and his collaborator Edwin G. Krebs were awarded the Nobel Prize in Physiology or Medicine in 1992 for describing how reversible phosphorylation works as a switch to activate proteins and regulate various cellular processes.

[12] At age seven, Fischer and his two elder brothers, Raoul and George,[13] were sent to the Swiss boarding school La Châtaigneraie, near his mother's hometown in Vevey.

[8] At high school he made a pact with a childhood friend, one of them would become a doctor and the other a scientist and then they could cure the ills of the world.

He completed a PhD in organic chemistry under the supervision of Kurt Heinrich Meyer, who worked on the structure of polysaccharides, and the enzymes needed for their synthesis and breakdown.

[17] Six months after his arrival in Seattle, Fischer learnt of fellow biochemist from the same university, Edwin G. Krebs, who was also trying to answer a similar question on where muscles received the energy that they needed to contract.

[8] Krebs and Fischer defined a series of reactions leading to the activation/inactivation of this enzyme as triggered by hormones and calcium, and in the process discovering the cycle of protein phosphorylation and hydrolysis.

The shape and the function of this protein is thus altered enabling it to take part in converting glycogen into glucose which is used for fuel for muscular contractions.

For the discovery of the cycle of phosphorylation and hydrolysis Fischer and Krebs were awarded the Nobel Prize for Physiology or Medicine in 1992, for explaining how the reaction acted as a switch to activate proteins and regulate various biochemical cellular processes.

[21] Fischer was a member of the St. George's University-based Windward Islands Research and Education Foundation (WINDREF) Scientific Advisory Board from 1994 to 2021.