How does telomerase meet the challenge of replicating the ends of linear chromosomes?
How does the enzyme telomerase meet the challenge of replicating the ends of linear chromosomes? It catalyzes the lengthening of telomeres, compensating for the shortening that occurs during replication. … DNA synthesis can take place only in the 5′ to 3′ direction.
What is the importance of telomerase in the challenge of replicating the ends of linear chromosome?
The ends of the linear chromosomes are known as telomeres: repetitive sequences that code for no particular gene. These telomeres protect the important genes from being deleted as cells divide and as DNA strands shorten during replication.
How are telomeres at the ends of eukaryotic chromosomes replicated quizlet?
Outline in words and pictures how telomeres at the ends of eukaryotic chromosomes are replicated. Telomeres are replicated by the enzyme telomerase. Telomerase, a ribonucleoprotein, consists of protein and an RNA molecule that is complementary to the 3′ end of the DNA of a eukaryotic chromosome.
What enzyme replicates DNA at the ends of the chromosomes?
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 of the following help to hold the DNA strands apart while they are being replicated?
Proteins called Binding Proteins keep the two DNA strands apart preserving the Replication Fork. A protein called Primase makes a short segment of RNA called the RNA Primer on the DNA termed the Template DNA. A protein called DNA Polymerase adds DNA Nucleotides to the RNA Primer on the Template DNA.
Which of the following is most likely to result from reduced or very little active telomerase activity?
Which of the following effects might be caused by reduced or very little active telomerase activity? Cells age and begin to lose function.
What does the enzyme telomerase 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.
How does telomerase solve end replication problem?
Telomerase is a reverse transcriptase that adds telomeric repeats to the 3′ ends of each chromosome (3). In doing so, telomerase makes up for the shortcomings of semiconservative DNA replication, which cannot complete the synthesis of chromosome ends.
What is telomerase and why is it important?
The enzyme telomerase adds TTAGGG repeats onto mammalian telomeres, which prevents their shortening. … The activation of telomerase in malignant cancers seems to be an important step in tumorigenesis, whereby the cell gains the ability of indefinite proliferation to become immortal.
How are telomeres replicated in eukaryotes?
Telomeres are the physical ends of eukaryotic chromosomes. They protect chromosome ends from DNA degradation, recombination, and DNA end fusions, and they are important for nuclear architecture. Telomeres provide a mechanism for their replication by semiconservative DNA replication and length maintenance by telomerase.
What is the end replication problem why in the absence of telomerase do the ends of the linear chromosomes get progressively shorter each time the DNA is replicated?
Why, in the absence of telomerase, do the ends of chromosomes get progressively shorter each time the DNA is replicated? In the absence of telomerase, DNA polymerase will be unable to add nucleotides to the end of the strand.
What is the end replication problem why in the absence of telomerase?
This is known as the end replication problem. It occurs because the lagging strands of the DNA do not get synthesized for the end of the DNA after the removal of RNA primers. The end sequence of the DNA in eukaryotes is known as a telomere, which is a repetitive sequence.
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.
How does the telomerase work?
How does telomerase work? The enzyme binds to a special RNA molecule that contains a sequence complementary to the telomeric repeat. It extends (adds nucleotides to) the overhanging strand of the telomere DNA using this complementary RNA as a template.
How does telomerase prevent DNA shortening?
Your DNA strands become slightly shorter each time a chromosome replicates itself. Telomeres help prevent genes from being lost in this process. … Telomerase does this by adding additional telomere sequences to the ends of your chromosomes.