Question

Which chemical linkage is responsible for joining two distinct nucleotides together to form a polynucleotide chain?

Options

• Hydrogen bonding

• N-glycosidic linkage

• 3'–5' Phosphodiester linkage

• Ester linkage

Answer 1

The 3'–5' Phosphodiester linkage joins two distinct nucleotides together to form a dinucleotide and subsequently a polynucleotide chain. This linkage connects the 5' carbon of one sugar to the phosphate group attached to the 3' carbon of the adjacent sugar, creating the sugar-phosphate backbone of nucleic acids.