This article will talk about the structure of telomerase and the knowledge points corresponding to the structure and function of telomeres. The article may be a bit long, but I hope you can read it to the end. Increase your own knowledge. The most important thing is that I hope it will be helpful to you and solve your problems. Don\’t forget to bookmark this site.
Contents of this article
- What are telomeres
- The structure and function of telomeres in more detail
- What is telomere length? Meaning
- The similarities and differences between DNA replication and telomere replication
1. What are telomeres
1. Telomeres are special DNA sequences that exist at the ends of chromosomes. They consist of repeated short sequences that protect the ends of chromosomes from damage and breakdown.
2. When cells divide, due to the limitations of the DNA replication mechanism, the DNA sequences at the ends of chromosomes will gradually shorten, and the length of telomeres will also decrease. When telomeres become too short, chromosome stability is threatened, easily causing chromosomal breaks and abnormalities.
3. Telomerase is a special enzyme that can extend the length of telomeres and maintain the stability of chromosomes. Cell telomeres are closely related to the occurrence and development of many diseases such as aging and cancer, so their research is of great significance.
2. The structure and function of telomeres in more detail
1. Telomeres are special structures composed of short multiple repeated non-transcribed sequences (TTAGGG) and some binding proteins. In addition to providing buffers for non-transcribed DNA, they can also protect chromosome ends from fusion and degradation. Chromosomes play an important role in positioning, replication, protection and control of cell growth and lifespan, and are closely related to apoptosis, cell transformation and immortalization. When a cell divides once, the telomeres of each chromosome will gradually become shorter. About 50 to 200 nucleotides of the genes that make up the telomeres will not be fully replicated (lost) due to multiple cell divisions, and the cell will terminate. Its functions are no longer fragmented. Therefore, severely shortened telomeres are a sign of cellular aging. In some cases where an infinite copy loop is requiredIn cells, the length of telomeres is retained after each cell division by the special DNA polymerase telomerase that can synthesize telomeres.
2. Stabilize the structure of chromosome ends, prevent terminal connections between chromosomes, and compensate for the vacancy caused by the elimination of RNA primers at the 5\’ end of the lagging strand.
3. Tissue culture cells prove that telomeres play an important role in determining the lifespan of animal and plant cells. After many generations of culture, the telomeres of aging cells change. short, the chromosomes also become unstable.
4. The more times a cell divides, the more its telomeres are worn and the shorter its lifespan is. Under normal circumstances, exercise accelerates cell division. The greater the amount of exercise, the more times the cells divide, and therefore the shorter the life span. Therefore, sports must be done in moderation.
3. What does telomere length mean
Generally, it is stable The meaning of chromosome end structure. Telomeres are a major factor in maintaining the integrity and stability of chromosomes. They can prevent chromosomes from fusing with each other, protect chromosomes from degradation by nucleases, provide substrates for telomerase, and ensure complete replication of chromosomes.
4. Similarities and differences between DNA replication and telomere replication
Required The enzymes are different. Telomere replication requires telomerase, and DNA replication requires DNA polymerase. Moreover, DNA replication initiation requires RNA primers, while telomere replication does not require primers. Telomeres are special structures at the ends of chromosomes in eukaryotic cells, consisting of DNA segments with repeated sequences and their binding proteins. Different species have their own unique repeat sequences. Every time DNA is copied, telomeres are \’worn down\’.
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