Question

Put the following steps of DNA replication in chronological order.

1.Single-stranded binding proteins attach to DNA strands.
2. Hydrogen bonds between base pairs of antiparallel strands are broken.
3.Primase binds to the site of origin.
4.DNA polymerase binds to the template strand.
5.An RNA primer is created.

A) 1, 2, 3, 4, 5
B) 2, 1, 3, 5,4
C) 3, 2, 1, 5,4
D) 3, 1, 2, 4,5 4

Answer 1

B) option is correct

Step-by-step explanation:

• Hydrogen bonds between base pairs of antiparallel strands are broken: DNA helicase catalyse ATP dependent separation of DNA strand and moves along with template which have 5'-3' orientation
• Single-stranded binding proteins attach to DNA strands: Single strand binding proteins binds with single strands and prevent reannealing of both strands, this binding is sequence independent (cooperatively) and stabilized by ionic interactions
• Primase binds to the site of origin: Primase synthesizes primer during DNA replication which provides 3'-OH group required for phosphodiester bond formation
• An RNA primer is created: DNA bound Dna B protein recruit primase enzyme called Dna G protein which catalyzes synthesis of primer
• DNA polymerase binds to the template strand: DNA dependent synthesis of new DNA is catalysed by a metalloenzyme called DNA polymerase and there are two basic requirements of DNA polymerase: template, which provides information of nucleotide selection and primer which provides 3'-OH group required for phosphodiester bond