Question

The phosphate group in a nucleotide is attached to which carbon of the pentose sugar?

Options

• The 3′ carbon

• The 1′ carbon

• The 5′ carbon

• The 2′ carbon

Answer 1

The phosphate group is attached to the 5′ carbon of the pentose sugar via a phosphoester bond. This attachment at the 5′ position is crucial for forming the polynucleotide chain through 3′–5′ phosphodiester linkages between successive nucleotides.