What is the function of topoisomerase group of answer choices?

What is the function of topoisomerase group of answer choices?

Correct answer: Explanation: Topoisomerase functions to untangle the supercoiling of DNA, which is when DNA overwinds into itself. This mechanism facilitates the unwinding action of helicase during replication.

What is the function of the enzyme DNA polymerase in replication quizlet?

The DNA polymerase is the enzyme that joins individual nucleotides to produce a new strand of DNA it produces the sugar phosphate bonds that join the nucleotides together and it proof reads each new DNA strand so that each copy is a near perfect copy of the original.

What is the difference between DNA gyrase and topoisomerase?

DNA gyrase and topoisomerase IV are the two type II topoisomerases present in bacteria. Gyrase is involved primarily in supporting nascent chain elongation during replication of the chromosome, whereas topoisomerase IV separates the topologically linked daughter chromosomes during the terminal stage of DNA replication.

What causes supercoiling of DNA?

Supercoiling occurs when the molecule relieves the helical stress by twisting around itself. The hydrogen bonds (holding together complementary bases) break and part of the double helix separates. Strand separation is required for transcription (copying DNA to RNA) and replication (copying DNA to DNA).

What are the advantages of coiling the DNA?

The Importance of DNA Supercoiling Supercoiling of DNA reduces the space and allows for much more DNA to be packaged. In prokaryotes, plectonemic supercoils are predominant, because of the circular chromosome and relatively small amount of genetic material.

What do you think are the advantages of coiling the DNA?

The double helix of DNA is then wrapped around certain proteins known as histones. This allows the DNA to be more tightly wrapped and therefore take up less space within the cell. The DNA can condense even further by the histones coming into close proximity to each other.

Why is it important for DNA to condense into chromosomes quizlet?

By condensing DNA into chromosomes, cells can align each chromosome (or during meiosis, each tetrad), along the metaphase plate. The spindle fibers can then pull apart sister chromatids (in Mitosis) or homologous chromosomes (Meiosis I). The cell continues to grow during this phase, as well.

Does Supercoiling occur in eukaryotes?

In eukaryotes, DNA supercoiling exists on many levels of both plectonemic and solenoidal supercoils, with the solenoidal supercoiling proving most effective in compacting the DNA.

Why does negative supercoiling facilitate replication and transcription?

Because negative supercoiling favors the unwinding of the DNA double helix that is required for formation of the open complex, it is expected to increase the rate of transcription for promoters in which open complex formation is rate limiting. Indeed most genes are activated by increased negative supercoiling.

What does topoisomerase mean?

: any of a class of enzymes that reduce supercoiling in DNA by breaking and rejoining one or both strands of the DNA molecule.

What happens if topoisomerase is not functional in prokaryotes?

In cells lacking the activity of topoisomerase I the chromosomal DNA becomes hypernegatively supercoiled, especially behind transcribing RNAP complexes. DNA gyrase will remove the positive torsional stress in front of RNAP, whereas the negative supercoils will persist if they cannot be relaxed by Topo I.

Is topoisomerase A protein?

Eukaryotic DNA topoisomerase I (Top1) is a monomeric protein clamp that functions in DNA replication, transcription, and recombination.

Do eukaryotes have topoisomerase?

Early studies in eukaryotes demonstrated the presence of both type I and type II topoisomerases. The eukaryotic type I enzyme was demonstrated to differ from the prokaryotic enzyme in its ability to relax both positive and negative supercoils (Champoux and Dulbecco, 1972).

Why does type 2 topoisomerase require ATP?

Type IIA topoisomerases are ATP-dependent enzymes that have been shown to simplify the topology of their DNA substrates to a level beyond that expected at equilibrium (i.e. more relaxed than the product of relaxation by ATP-independent enzymes, such as type I topoisomerases, or a lower than equilibrium level of …

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