Telomeres are found at the ends of eukaryotic chromosomes. How does telomerase assemble telomeres?

Key Concepts

Telomeres

Telomeres are repetitive nucleotide sequences located at the ends of eukaryotic chromosomes. They protect the chromosome from deterioration or fusion with neighboring chromosomes, which is crucial for maintaining genomic stability. Each time a cell divides, telomeres shorten, which is associated with aging and cellular senescence.

Telomerase

Telomerase is an enzyme that adds nucleotide sequences to the ends of telomeres, counteracting their shortening during DNA replication. It is composed of a protein component and an RNA template that guides the addition of telomeric repeats. Telomerase activity is particularly high in stem cells and cancer cells, allowing them to divide indefinitely.

Mechanism of Telomere Assembly

The assembly of telomeres by telomerase involves a process where the enzyme binds to the existing telomere and extends it by adding specific DNA sequences. This extension occurs through reverse transcription, where the RNA template within telomerase is used to synthesize new DNA. This mechanism is vital for maintaining telomere length and ensuring proper chromosome function during cell division.