Peter D. Mitchell, English biochemist and academic, Nobel Prize laureate (died 1992)

Peter Dennis Mitchell FRS was a British biochemist who was awarded the 1978 Nobel Prize for Chemistry for his theory of the chemiosmotic mechanism of ATP synthesis.

The Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outstanding contributions in chemistry, physics, literature, peace, and physiology or medicine. This award is administered by the Nobel Foundation and awarded by the Royal Swedish Academy of Sciences on proposal of the Nobel Committee for Chemistry, which consists of five members elected by the Academy. The award is presented in Stockholm at an annual ceremony on December 10th, the anniversary of Nobel's death.

September 29 is the 272nd day of the year in the Gregorian calendar; 93 days remain until the end of the year.