Question

Single strands of nucleic acids are directional, meaning that there are two different ends. What functional groups define the two different ends of a strand?

Answer 1

Answer:

The 5' end has free phosphate group while the 3' end has free OH group.

Explanation:

Each DNA strand has two ends that differ from each other with respect to the functional group. The nucleotide present at the 5' end of a DNA strand has a free phosphate group. This phosphate group of other nucleotides of the DNA strand is bonded in phosphodiester bonds. Likewise, the 3' end of a DNA has a free OH group. This makes the two ends of a DNA strand quite different from each other. A DNA new nucleotide can be added to the 3' end due to the presence of a free OH group.