3′ End

Definition

The 3′ End of a nucleic acid is the end of the molecule where the third carbon (3′ carbon) of the sugar in the sugar-phosphate backbone is not bound to another nucleotide. This terminus is crucial for determining the directionality of DNA and RNA synthesis.

Related terms

5′ End:

The opposite end of a nucleic acid strand where the fifth carbon (5′ carbon) of the sugar is available or attached to a phosphate group, marking another point of directionality for DNA and RNA.

Phosphodiester Bond:

A chemical bond between two nucleotides that forms when the phosphate group of one nucleotide binds to the 3′ hydroxyl group of another, creating the backbone of DNA or RNA strands.

Polymerase: An enzyme that catalyzes the synthesis of nucleic acids on preexisting DNA or RNA templates, essentially working from the 5′ end towards the 3′ end to add complementary nucleotides