Question

The 3′ end of a polynucleotide chain is characterized by the presence of:

Options

• A free –OH group attached to the 3′ carbon of the sugar

• An N-glycosidic bond

• A free phosphate group attached to the 3′ carbon of the sugar

• A nitrogenous base

Answer 1

The 3′ end of a polynucleotide chain is the terminating end and is characterized by a free hydroxyl (–OH) group attached to the 3′ carbon of the pentose sugar. This is in contrast to the 5′ end, which has a free phosphate group.