Multiple choice The enzyme unwinding the DNA strands are DNA topoisomerases helicases SSB protein (single-stranded DNA-binding protein) DNA ligase Reveal answer Fill a bubble to check yourself B Correct answer Explanation Helicases are proteins that unwind DNA using energy of ATP and create two potential replication forks. 5' to 3' helicase unwind DNA from 5' single stranded end while 3' to 5' helicase unwind DNA at 3' single stranded end.