AP BIOLOGY

Detailed explanation-1: -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. As the helicase moves along the DNA molecule, it continues breaking these hydrogen bonds and separating the two polynucleotide chains (Figure 1).

Detailed explanation-2: -To unwind a long stretch of DNA, a helicase has to move unidirectionally along the DNA and couple translocation to local base pair separation. As the helicase moves along the DNA, it successively makes and breaks interactions with the DNA.

Detailed explanation-3: -DNA helicases are molecular motors. Through conformational changes caused by ATP hydrolysis and binding, they move along the template double helix, break the hydrogen bonds between the two strands and separate the template chains, so that the genetic information can be accessed.

Detailed explanation-4: -Helicase is the enzyme that breaks the hydrogen bonds between the bases of DNA. During DNA replication, helicase melts the hydrogen bonds between complementary base pairs.

Detailed explanation-5: -During DNA replication, DNA helicases unwind DNA at positions called origins where synthesis will be initiated. DNA helicase continues to unwind the DNA forming a structure called the replication fork, which is named for the forked appearance of the two strands of DNA as they are unzipped apart.