CHEMICAL COMPOSITION OF DNA Flashcards
building blocks of DNA
nucleotides
components of Nucleotides
Phosphate backbone (negatively charged); Pentose sugar and Nitrogenous bases ATGC - (basic)
Nucleosides
precursor of Nucleotides: sugar and nitrogenous bases
basic, flat aromatic rings with conjugated double bonds and multiple sites for hydrogen bonding
NITROGENOUS BASES
bases that have double rings
PURINE (ADENINE AND GUANINE)
bases that have one ring
PYRIMIDINE (THYMINE AND CYTOSINE)
heterocyclic aromatic compound; pyrimidine fused with an imidazole ring (double ring)
PURINES (Adenine (6-aminopurine) and Guanine (2-amino-6-oxypurine)
heterocyclic aromatic compound similar to benzene and pyridic(single ring)
PYRIMIDINE (Thymine (2,4-dioxy-5-methyl pyrimidine) , Cytosine (2-oxy-4-aminopyrimidine) and Uracil (2,4- dioxy-pyrimidine)
rapid introconversion of isomeric forms
TAUTOMERIZATION OF BASES
TRUE OR FALSE: Tautomerism leads to anomalous base pairing.
TRUE
Formation of nucleotides
linked by covalent bonds, producing 2 water molecules
Phosphoester bond
phosphate and sugar
N-glycosidic bond
sugar and nitrogenous bases
component of the backbone of the polynucleotide together with the pentose; imparts negative charge to the DNA
PHOSPHATE GROUPS
The _____________ enable DNA to associate with proteins (e.g. histones - positively charged)
negative charge of phosphates