From 1969 till 1971 Sir John Walker works at The School of Pharmacy at the University of Wisconsin in the United States.

Then Sir John Walker jobs at the CNRS at Gif-sur-Yvette and the Institut Pasteur in France, while NATO and EMBO (The European Molecular Biology Organization) support him.

„[F]or their elucidation of the enzymatic mechanism underlying the synthesis of adenosine triphosphate (ATP)" Sir John Walker and the American Paul Boyer are awarded the Nobel Prize in Chemistry in 1997.

Growing up in Rastrick, Sir John Walker visits the Rastrick Grammar School, where he specializes in Physical Science and Mathematics.

Since 1982 Sir John Walker serves as a senior scientist at the LMB.

During that time there are many important scientific developments arising at the LMB, like the sequencing of DNA. Sir John Walker works on the genetic code in mitochondria. In 1978 he applies protein chemical methods to membrane proteins. This decision opens the complete structural analysis of the adenosine triphosphate (ATP) syntheses and gives a new biological input into ATP.

In 1965 Sir John Walker starts researches on peptide antibiotics in the School of Pathology, Oxford. He gains his PhD in Chemistry in 1969.

From 1960 till 1964 Sir John Walker studies Chemistry at the St. Cathrine's College, University of Oxford.

In 1963 Sir John Walker and Christina Westcott get married. They have two daughters named Esther (b.1976) and Miriam (b. 1978).

Sir John Ernest Walker is born in 1941 to his parents Elsie (née Lawton) an amateur musician and Thomas Ernest, a stone mason. He has two younger sisters named Judith and Jennifer.

After participating in a research workshop in Cambridge with the focus on the Sequence Analysis of Proteins and meeting the Nobelist in Chemistry Fred Sanger, Sir John Walker gets the chance to work three months at the Protein and Nucleic Acid Chemistry Division at the Laboratory of Molecular Biology (LMB). The three months become eight years, which he works as an assistant.