A nucleoside, composed of a nucleobase, is either a pyrimidine (cytosine, thymine or uracil) or a purine (adenine or guanine), a five carbon sugar which is either ribose or deoxyribose. ... Nucleosides are responsible for encoding, transmitting and expressing genetic information in all living things.

Is thymine A nucleotide?

Thymine is one of the building blocks of DNA. It's one of the four nucleotides that are strung together to make the long sequence that you find in DNA, of C, A, Gs, and Ts. ... And in the double helix, thymine pairs with adenine, or the A nucleotide.

Is adenine A nucleoside?

Adenine is one of the two purine nucleobases (the other being guanine) used in forming nucleotides of the nucleic acids. ... Adenine forms adenosine, a nucleoside, when attached to ribose, and deoxyadenosine when attached to deoxyribose.