Question

Which of the following enzymes listed below are responsible for cancer cells ability to prevent aging of the cells and contributes to cellular immortality that is so characteristic of this disease process?

Answer 1

Answer:

Telomerase

Explanation:

Repetitive regions at the ends of Chromosomes are known as telomeres and these are crucial for chromosomal stability. There is no gene present and they provide protection to internal parts of chromosome. The telomeres are eaten up slowly by ‘DNA REPAIR MECHANISM’ after many division cycles, which is considered as ageing. That why, a cell can divide only certain number of times.

Some cells have ability to express an enzyme telomerase that maintain the length of telomere. The telomerase enzyme contributes to cell immortality by rebuilding the damaged telomere. Thus telomerase enzyme is necessary for cancer initiation and survival of tumor. Telomerase enzyme can make its own DNA by using its RNA as template . It extends the overhang strands of DNA by using a comlementary DNA.