Final answer:
Telomerase is an enzyme that extends the telomeres at chromosome ends to prevent their shortening during cell division, a process associated with aging. It is active in germ cells, stem cells, and many cancer cells and could have therapeutic uses in regenerative medicine and cancer treatment.
Step-by-step explanation:
Telomerase is an enzyme complex that is crucial for the replication of chromosome ends, known as telomeres. This enzyme includes a catalytic part as well as an internal RNA template, which it uses to add nucleotides to the 3' end of telomeres, thus compensating for the shortening that occurs during DNA replication. This process is important in cells that divide regularly, such as germ cells, stem cells, and in many cancer cells. In the context of regenerative medicine and aging, the activity of telomerase has been found to reverse some age-related conditions in mice by extending telomeres and reducing DNA damage, which presents a potential therapeutic strategy for age-related diseases in humans. However, it's not active in most adult somatic cells, which contributes to the aging process as telomeres gradually shorten with successive cell divisions.
For her discovery of telomerase, Elizabeth Blackburn received the Nobel Prize in Physiology or Medicine in 2009. In addition, substances that can inhibit the function of telomerase are of interest in cancer therapy since they could potentially stop the division of cancer cells by preventing the stabilization of their telomeres.