Helicases are very important in DNA replication because they are responsible for opening the double helix by breaking the hydrogen bonds. So an enzyme that attaches many pieces of DNA. Molecular Mechanism Of Dna Replication Article Khan Academy Complementaryspecific base pairing AT and GC. . Describe the role of two named enzymes in the process of semi-conservative replication of DNA DNA helicase breaks the hydrogen bonds between DNA strands separating the double-stranded DNA into single strands and exposing the nucleotide basesDNA polymerase joins adjacent DNA nucleotides through formation of phosphodiester bonds forming the sugar-phosphate. Individual strands of DNA are manufactured in different directions producing a leading and a lagging strand. Semi-conservative replication new DNA molecules contain one old strand and one new strand. Helicase unwinds the DNA double helix Gyrase relieves the buildup of torque during un...