Elizabeth Blackburn won the 2009 Nobel Prize for discovering how chromosomes are protected by telomeres and telomerase.
Blackburn studied telomeres, repetitive DNA sequences at chromosome ends that help prevent chromosomes from being mistaken for damaged DNA. With Carol Greider and Jack Szostak, she helped establish how telomerase maintains these protective ends.
The Nobel committee awarded the 2009 Prize in Physiology or Medicine to all three scientists. Their findings clarified a basic mechanism of chromosome stability and influenced research into aging, cancer, and inherited disorders.
A common oversimplification says telomeres are simply an “aging clock.” In reality, telomere biology is complex: telomerase can be active in some normal cells and is also commonly reactivated in cancer cells. Blackburn’s Nobel recognition was for fundamental cellular biology, not for proving a single universal cause of aging.