Minute to Understanding: What are telomeres?

What are telomeres? Telomeres are structures made from DNA sequences and proteins found at the ends of chromosomes. They cap and protect the end of a chromosome like the end of a shoelace.

In almost all animals, from the simplest to the most complex, telomeres are required for cell division. With each cell replication, the telomeres get shorter and shorter until they're so short that your cells can no longer divide. When cells no longer divide, tissues age. However, telomeres can be rebuilt by an enzyme called telomerase to restore cell division.

If you think we've found the fountain of youth, think again. If a cell keeps dividing uncontrollably and overcomes the limitations of telomeres, a cancerous tumor can form. This is why telomeres are so important. In healthy cells, they achieve the necessary balance between limiting cellular lifespan and your own longevity and keeping cancer growth at bay.