AP BIOLOGY

THE MOLECULAR BASIS OF INHERITANCE

DNA REPLICATION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Enzyme that unzips the DNA to prepare for replication
A
polymerase III
B
helicase
C
topoisomerase
D
ligase
Explanation: 

Detailed explanation-1: -The first step in DNA replication is to ‘unzip’ the double helix structure of the DNA? molecule. This is carried out by an enzyme? called helicase which breaks the hydrogen bonds? holding the complementary? bases? of DNA together (A with T, C with G).

Detailed explanation-2: -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.

Detailed explanation-3: -Abstract. Helicases are essential enzymes involved in all aspects of nucleic acid metabolism including DNA replication, repair, recombination, transcription, ribosome biogenesis and RNA processing, translation, and decay.

Detailed explanation-4: -DNA helicases catalyze the disruption of the hydrogen bonds that hold the two strands of double-stranded DNA together. This energy-requiring unwinding reaction results in the formation of the single-stranded DNA required as a template or reaction intermediate in DNA replication, repair and recombination.

Detailed explanation-5: -An enzyme called RNA polymerase travels along the DNA, unzipping its two strands. The molecule then copies one of the strands of DNA into a strand of RNA. This animation brings the process to life, showing three-dimensional representations of the molecules involved.

There is 1 question to complete.