What is the sequence of telomerase?
Telomeres are sections of DNA? found at the ends of each of our chromosomes?. They consist of the same sequence of bases?repeated over and over. In humans the telomere sequence is TTAGGG. This sequence is usually repeated about 3,000 times and can reach up to 15,000 base pairs? in length.
What is the sequence composition of telomeres?
Telomeres are made up of repeated segments of DNA that consist of the sequence 5′-TTAGGG-3′ (in which T, A, and G are the bases thymine, adenine, and guanine, respectively). Some human cells contain as many as 1,500 to 2,000 repeats of this sequence at each end of each chromosome.
Why are telomeres repeating sequences of DNA?
To prevent the loss of genes as chromosome ends wear down, the tips of eukaryotic chromosomes have specialized DNA “caps” called telomeres. Telomeres consist of hundreds or thousands of repeats of the same short DNA sequence, which varies between organisms but is 5′-TTAGGG-3′ in humans and other mammals.
What is the gene for telomerase?
The TERT gene provides instructions for making one component of an enzyme called telomerase. Telomerase maintains structures called telomeres, which are composed of repeated segments of DNA found at the ends of chromosomes.
Which strand does telomerase extend?
Telomerase adds complementary RNA bases to the 3′ end of the DNA strand. Once the 3′ end of the lagging strand template is sufficiently elongated, DNA polymerase adds the complementary nucleotides to the ends of the chromosomes; thus, the ends of the chromosomes are replicated.
Which is a characteristic of DNA sequences at the telomeres?
Which is a characteristic of DNA sequences at the telomeres? -One strand protrudes beyond the other, creating some single-stranded DNA at the end.
How does telomerase assemble telomeres?
How does telomerase assemble telomeres? Telomerase uses a segment of its RNA as the template to add multiple copies of a simple sequence to the 3′ end of each strand of DNA on a linear chromosome. This strand is copied by the normal mechanism of lagging strand synthesis after it is extended by telomerase.
Do telomeres consist of direct repeat sequences?
Telomeres consist of direct repeat sequences. In the absence of telomerase activity, chromosomes are shortened slightly after every round of replication.
How are telomeres an example of repetitive DNA?
Telomeres are repetitive DNA sequences that are wrapped in specific protein complexes and located at the ends of linear chromosomes. Telomeres distinguish natural chromosome ends from DNA double-stranded breaks and thus promote genome stability.
Which cells are most likely to have the gene for making telomerase switched on?
Cells with short telomeres can no longer divide, so damaged tissues cannot be repaired. Which cells are most likely to have the gene for making telomerase switched on? The cells in a developing embryo.
How does the telomerase work?
In egg and sperm cells, an enzyme called telomerase keeps adding more of the repeating sequence onto the end of DNA strands, so that the telomeres in these cells don’t shorten. In other cells, telomerase is less active, leading to the gradual shortening of telomeres over time.
Is telomerase on leading or lagging strand?
Once the lagging strand is elongated by telomerase, DNA polymerase can add the complementary nucleotides to the ends of the chromosomes and the telomeres can finally be replicated.
What is telomerase and what does it do?
Telomerase, also called telomere terminal transferase, is an enzyme made of protein and RNA subunits that elongates chromosomes by adding TTAGGG sequences to the end of existing chromosomes. Telomerase is found in fetal tissues, adult germ cells, and also tumor cells.
How to regrow telomeres and increase telomerase naturally?
Exercise and Telomere Length Studies show that the more physically active you are the longer your telomeres.
How does telomerase bind to DNA?
– Yeast Ku’s telomeric functions require its DNA-binding ring – Ku mutation that inhibits DNA binding unexpectedly inhibits telomerase RNA binding – Competition experiments show mutually exclusive binding of DNA and RNA to Ku – Supports new model for recruitment of telomerase to telomeres by Ku
What is the connection between telomerase and cancer?
following a healthy diet