Nucleic Acids

Flashcards based on the Nucleic Acids lecture notes.

Nucleobase

Nitrogenous base

Nucleoside

Nitrogenous base + Pentose sugar

Nucleotide

Nitrogenous base + Pentose sugar + Phosphate

Nucleobases

Derivatives of pyrimidine or purine; Nitrogen-containing heteroaromatic molecules; Planar or almost-planar structures; Absorb UV light around 250–270 nm

N-glycosidic bond

In nucleosides, the pentose ring is attached to the nucleobase via an N-glycosidic bond.

Phosphate Group

Negatively charged at neutral pH; Typically attached to 5’ position; Nucleic acids are built using 5’-triphosphates; Nucleic acids contain one phosphate per nucleotide

Nucleotide Functions

Energy for metabolism (ATP); Enzyme cofactors (NAD+); Signal transduction (cAMP)

Nucleic Acid Functions

Storage of genetic info (DNA); Transmission of genetic info (mRNA); Processing of genetic information (ribozymes); Protein synthesis (tRNA and rRNA)

UV Absorption of Nucleotides

Absorption of UV light at 250–270 nm is due to   * electronic transitions.

Excited states of common nucleobases decay rapidly via radiationless transitions

Effective photoprotection of genetic material; No fluorescence from nucleic acids

Pentose in RNA

-D-ribofuranose

Pentose in DNA

-2’-deoxy-D-ribofuranose