Jack William Szostak FRS (born November 9, 1952)[2] is a Canadian American[3] biologist of Polish British descent, Nobel Prize laureate, university professor at the University of Chicago, former professor of genetics at Harvard Medical School, and Alexander Rich Distinguished Investigator at Massachusetts General Hospital, Boston.

He was awarded the 2009 Nobel Prize for Physiology or Medicine, along with Elizabeth Blackburn and Carol W. Greider, for the discovery of how chromosomes are protected by telomeres.

He completed his PhD in biochemistry at Cornell University (advisor Prof. Ray Wu[6]) before moving to Harvard Medical School to start his own lab at the Sidney Farber Cancer Institute.

In the early 90s his laboratory shifted its research direction and focused on studying RNA enzymes, which had been recently discovered by Cech and Altman.

[8] They have conducted detailed studies of mechanisms by which RNA templates may have replicated on early Earth before the emergence of enzyme catalysts.

[9] Significantly, the Szostak group discovered that phosphorimidazolide-mediated template elongation occurs via 5'-5'-imidazolium bridged dinucleotide intermediates[10] which accelerate polymerization.

Szostak and Katarzyna Adamala demonstrated that the issues of a degrading effect of magnesium ions on RNA and the disruption of a fatty acid membrane by magnesium ions can be simultaneously solved by the presence of weak cation chelator like citric acid in primitive protocells.

[15] He has received the following awards: An organism's genes are stored within DNA molecules, which are found in chromosomes inside its cells' nuclei.