Describe the function of enzymes DNA helicase and DNA polymerase during DNA replication (2 marks)
DNA replication occurs in two phases: DNA separation (DNA helicase) and DNA transcription (DNA polymerase)
Enzyme Function:
1. DNA helicase – (unwinding DNA and) breaking hydrogen bonds between DNA strands (1 mark)
2. DNA polymerase – joins (adjacent) nucleotides OR forms sugar- phosphate backbone (1 mark)
Analogy to remember:
Like opening (DNA helicase) and reading (DNA polymerase) a book.
Exam technique:
Emphasise the importance of key terms e.g. "adjacent" and "unwinding" in achieving full marks in regard to A-level mark-schemes (e.g. AQA, OCR Edexcel).
BJ
Related Biology A Level answers
All answers ▸What is the risk of a child inheriting haemophilia A, when both parents are unaffected, but the mothers father suffered from the condition?
Explain the concept of natural selection. Give an example.
How do organisms generate ATP?
What is the difference between haploid and diploid cells? (2 Marks)