What is the first thing that occurs in DNA replication?
The initiation of DNA replication occurs in two steps. First, a so-called initiator protein unwinds a short stretch of the DNA double helix. Then, a protein known as helicase attaches to and breaks apart the hydrogen bonds between the bases on the DNA strands, thereby pulling apart the two strands.
Where would the enzyme topoisomerase attach during DNA replication?
Answer and Explanation: The enzyme topoisomerase attaches to DNA in front of the replication fork.
What enzyme deals with Supercoils?
Topoisomerase. Topoisomerases are enzymes that are responsible for the introduction and elimination of supercoils. Positive and negative supercoils require two different topoisomerases.
What is the function of the enzyme topoisomerase in DNA replication group of answer choices?
Helicase unwinds the helix, and single-strand binding proteins prevent the helix from re-forming. Topoisomerase prevents the DNA from getting too tightly coiled ahead of the replication fork. DNA primase forms an RNA primer, and DNA polymerase extends the DNA strand from the RNA primer.
What is topoisomerase in DNA replication?
Topoisomerases (or DNA topoisomerases) are enzymes that participate in the overwinding or underwinding of DNA. The winding problem of DNA arises due to the intertwined nature of its double-helical structure. During DNA replication and transcription, DNA becomes overwound ahead of a replication fork.
What is the difference between topoisomerase I and II?
Type I topoisomerases relax DNA (i.e., remove supercoils) by nicking and closing one strand of duplex DNA (see Figure 12-14). Type II topoisomerases change DNA topology by breaking and rejoining double-stranded DNA. Both replicated circular and linear DNA chromosomes are separated by type II topoisomerases.
What is the function of a topoisomerase in DNA replication quizlet?
What is the purpose of topoisomerase? unwinds the resulting supercoils. What keeps the DNA strands separated during replication?
What are the three main steps in DNA replication quizlet?
Terms in this set (3)Enzyme seperate DNA sides.New bases pair with bases on original DNA.Two new identical DNA molecules are produced.
What is the correct order of enzyme action during DNA replication?
Number the steps from 1 to 7. Synthesis of RNA primers (priming) Helicase/topoisomerase activity DNA polymerization/proofreading 5′-3′ exonuclease activity/DNA polymerization Ligation Single-stranded binding proteins bind and prevent reannealing Binding to origin of replication (AT rich sequence) II.
Where does DNA replication start in eukaryotes?
These complexes prepare cells for DNA replication during the S phase. Initiation of DNA replication in eukaryotes begins with the binding of the origin recognition complex (ORC) to origins of replication during the G1 phase of the cell cycle.