Why do telomeres shorten after replication?

At each cell division, the telomeres shorten because of the incomplete replication of the linear DNA molecules by the conventional DNA polymerases. This is specifically due to the resection and fill-in reaction during the synthesis of the telomere leading-strand [7,8].

What would happen if telomeres didn’t shorten?

They protect the ends of our chromosomes by forming a cap, much like the plastic tip on shoelaces. If the telomeres were not there, our chromosomes may end up sticking to other chromosomes. Without telomeres, important DNA would be lost every time a cell divides (usually about 50 to 70 times).

What happens if telomeres are too long?

Our cellular machinery results in a little bit of the telomere becoming lopped off each time cells replicate their DNA and divide. As telomeres shorten over time, the chromosomes themselves become vulnerable to damage. Eventually the cells die.

When do telomeres start to shorten?

In newborns, white blood cells have telomeres ranging from 8,000 to 13,000 base pairs in length, as compared with 3,000 in adults and only 1,500 in the elderly. After the newborn phase, the number of base pairs tends to decline by approximately 20 to 40 per year.

Why does telomere length decrease with age?

Telomeres, nucleoprotein structures located at the ends of eukaryotic chromosomes, protect the end of the chromosome from degradation and end-to-end fusion [1]. With each somatic cell division, there is a gradual attrition of the telomere, resulting in telomere length shortening with increasing age [1].

Why do telomeres shorten each time cells divide?

The telomere acts as a buffer to ensure the important genetic information coded for on the chromosome is completely copied for each new cell and protected from damage. Over time, this results in fewer and fewer DNA repeats making up the telomeres after each cell division i.e. gradually the telomeres shorten.

Why is it problematic to have too long or too short of telomeres?

Too much telomerase can help confer immortality onto cancer cells and actually increase the likelihood of cancer, whereas too little telomerase can also increase cancer by depleting the healthy regenerative potential of the body.

What are telomeres and why are they important how does telomerase play a role?

10 Telomere and Telomerase. Telomeres are repetitive nucleotide sequences at each end of chromosomes. Their function is to protect the ends of the chromosomes from deterioration or fusion to other chromosomes during cell division. With every cell division, telomeres shorten.