Question

Nucleic acids are assembled in the _____ direction.

A) 3' to 5'
B) 5' to 3'
C) 1' to 4'
D) 2' to 6'

Answer 1

Nucleic acids are assembled in the 5' to 3' direction, with new nucleotides being added to the 3' end of the growing strand by DNA polymerase, which progresses along the template strand in a 3' to 5' direction.

Step-by-step explanation:

Nucleic acids are assembled in the 5' to 3' direction. This means that during DNA replication or RNA synthesis, new nucleotides are added to the 3' end of the growing strand. DNA polymerase, which is the enzyme responsible for adding these nucleotides, moves along the template strand in a 3' to 5' direction, which allows the new strand to be synthesized in the 5' to 3' direction. One strand, known as the leading strand, is synthesized continuously, while the lagging strand is synthesized in shorter segments known as Okazaki fragments because DNA polymerase can only add nucleotides in the 5' to 3' direction. These fragments are later joined together by the enzyme DNA ligase to form a continuous strand. The DNA strands are held together by phosphodiester linkages, which create the backbone of the nucleic acid chains. This fundamental aspect of molecular biology ensures the correct replication and expression of genetic material following the central dogma of molecular biology: DNA to RNA to protein.