Science
What is Telomeres?
Telomeres are protective caps at the ends of your chromosomes, like the plastic tips on shoelaces. They keep DNA from fraying, but they shorten each time a cell divides — a process tied to aging and to how many times a cell can replicate.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains telomeres.
Key things to understand
- 1Repeated DNA sequences that shield chromosome ends from damage and accidental fusion.
- 2They get a little shorter with every cell division.
- 3When too short, the cell stops dividing (senescence) or dies — a driver of aging.
- 4An enzyme called telomerase can rebuild them; it's very active in stem cells and most cancers.
Frequently asked questions
- Do telomeres cause aging?
- Telomere shortening is one driver of cellular aging, but aging is complex and involves many other factors too.
- What is telomerase?
- An enzyme that lengthens telomeres. It keeps stem and reproductive cells young — and is hijacked by cancers to divide endlessly.
- Can you lengthen your telomeres?
- Lifestyle factors like exercise, less stress, and good sleep are linked to slower shortening, but no proven, safe method reliably lengthens them in humans.