How does telomerase work in cells?
Telomerase is a specialized enzyme that acts like a cellular repair kit for chromosome ends. Telomeres are repetitive DNA sequences that protect our chromosomes from fraying or fusing. Each time a cell divides, a small piece of telomere is lost because DNA replication machinery can't copy the very tip. Telomerase adds back those lost repeats, using its own RNA template as a guide. It's not active in most adult cells—only in stem cells, germ cells, and, unfortunately, many cancer cells. In normal cells, telomeres shorten over time, acting as a clock that limits cell division. When telomeres get too short, cells stop dividing or die. So telomerase is like a fountain of youth for cells, but it's not that simple—its reactivation in cancer is a double-edged sword.
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