Helicase unwinds the double helix at the fork while topoisomerase relieves the supercoiling strain ahead of it.
Helicase uses ATP to separate strands, and single-strand binding proteins stop them re-pairing. Winding ahead of the fork creates positive supercoils; topoisomerases cut and reseal DNA to release tension. Gyrase is bacterial topoisomerase II.
Quinolone antibiotics inhibit gyrase, and some cancer drugs inhibit human topoisomerases.
Helicase unwinds the double helix at the fork while topoisomerase relieves the supercoiling strain ahead of it.
Helicase and Topoisomerase is one of the 52 topics in Molecular Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Transcription, Ribosome Structure, DNA Replication.
Ciprofloxacin blocks bacterial DNA gyrase.
Work through the Beginner topics in Molecular Biology first, such as Central Dogma, DNA Replication, Base Pairing, then return to Helicase and Topoisomerase. Intermediate topics assume the Beginner vocabulary.
The closest topics to Helicase and Topoisomerase are Transcription, Ribosome Structure, DNA Replication, Transcription Factors. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Helicase and Topoisomerase. To practise the whole of Molecular Biology, use the Molecular Biology quiz.
Helicase and Topoisomerase: Helicase unwinds the double helix at the fork while topoisomerase relieves the supercoiling strain ahead of it. Transcription: The process of making an RNA copy of a gene using DNA as a template. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Transcription and explain the difference aloud. Finally, take the Molecular Biology quiz and come back to this page for any question you miss.
The process of making an RNA copy of a gene using DNA as a template.
🧫 Molecular BiologyA large and small subunit with A, P and E sites that coordinate tRNA binding and peptide bond formation.
🧫 Molecular BiologyThe copying of DNA before cell division so each daughter cell receives a full set of genes.
🧫 Molecular BiologyProteins that bind specific DNA sequences to turn genes on or off.
🧫 Molecular Biology