Telomeres

Telomeres are caps on the end of chromosomes that keep the chromosomes from unravelling and protect the chromosome’s genetic information.

Telomeres are like the plastic tips on the end of shoelaces that keep the chromosomes from fraying, and binding to other chromosomes.

Telomeres are repetitive sequences of DNA (nucleotide) that don’t contain genetic information, and are sometimes referred to as junk DNA. Telomeres serve to protect the integrity of the chromosome’s genetic information, and they also serve as a mechanism to limit the life of cells.

Every time a cell containing chromosomes replicates the chromosomes are duplicated. Enzymes duplicate the DNA but they cannot duplicate the DNA all the way to the end of the chromosome.

Each time a cell is duplicated a section at the end of the telomeres is lost and the telomeres become shorter. Since the telomeres don’t contain genetic information their shortening does not affect the integrity of the chromosome’s genetic information.

If the shortening were to take place on sections of the chromosome that contained genetic information the cells function would be compromised.

To stop this from happening one the telomeres are shortened to a certain length cells can no longer replicate and this leads to the aging of cells, cell death, or sometimes the cells transform into cancer cells.

Cell life can be extended increasing telomerase enzyme activity, which adds repetitive DNA back to the ends of telomeres.