Nucleosides vs. Nucleotides
Nucleosides
- Comprise a sugar and a base
Nucleotides
- Phosphorylated nucleosides (at least one phosphorus group)
- Link in chains to form polymers called nucleic acids (i.e. DNA and RNA)
N-beta-glycosidic bond
- Links nitrogenous base to sugar in nucleotides and nucleosides
- Purines: C1 of sugar bonds with N9 of base
- Pyrimidines: C1 of sugar bonds with N1 of base
PHOSPHOESTER BOND
- Links C3 or C5 hydroxyl group of sugar to phosphate
- Adenine
- Guanine
- Cytosine
- Thymine (DNA)
- Uracil (RNA)
- =sugar + base
- Adenosine
- Guanosine
- Cytidine
- Thymidine
- Uridine
Nucleotide monophosphates – add suffix 'sylate'
- = nucleoside + 1 phosphate group
- Adenylate
- Guanylate
- Cytidylate
- Thymidylate
- Uridylate
Add prefix 'deoxy' when the ribose is a deoxyribose: lacks a hydroxyl group at C2.
- Thymine only exists in DNA (deoxy prefix unnecessary for this reason)
- Uracil only exists in RNA
- Phosphodiester bonds: a phosphate group attached to C5 of one sugar bonds with
- OH group on C3 of next sugar
- Nucleotide monomers of nucleic acids exist as triphosphates
- Nucleotide polymers (i.e. nucleic acids) are monophosphates
- 5' end is free phosphate group attached to C5
- 3' end is free -OH group attached to C3