Chapter 4 - Nucleic Acids Flashcards
Nucleic Acids
Polymers specialized for the storage, transmission, and use of genetic info
Central Dogma of Molecular Biology
Flow of information: DNA (transcribed)—>RNA (translated)—>proteins; replication and transcription take place in the nucleus and translation takes place in the cytoplasmic area outside nucleus
Nucleotide
Monomers that make up nucleic acids; 3 components: a pentose sugar, a phosphate group and a nitrogenous base
Nucleoside
Nucleic acid monomer that consists of a pentose sugar and nitrogenous base (no phosphate group)
Nitrogenous base
Adenine, thymine, uracil (RNA), guanine and cytosine;
Pyrimidine
Nitrogenous base that contains a 6-membered single ring structure; includes cytosine, thymine, and uracil (RNA) (CUT)
Purine
Nitrogenous base that contains a fused double-ring structure; includes guanine and adenine (GA)
Ribose
RNA pentose sugar, Carbon-2 contains an –OH
Deoxyribose
DNA pentose sugar, Carbon-2 contains an –H
Phosphodiester linkage
Nucleotides are linked together in a condensation/dehydration reaction to form a bond; the phosphate groups link Carbon 3’ in one sugar to carbon 5’ in another sugar; nucleic acids grow in a 5’-to-3’ direction
Complementary base pairing
Purines pair with pyrimidines by hydrogen bonds; Adenine pairs with Thymine (or Uracil) with 2 hydrogen bonds; Guanine pairs with Cytosine with 3 hydrogen bonds
DNA
Deoxyribonucleic acid; holds A-T and C-G nitrogenous base pairing; double-stranded helix with antiparallel strands (5’-to-3’ and 3’-to-5’); 3’ always attached to a phosphate group or –OH, 5’ always attached to CH3
RNA
Ribonucleic acid; holds A-U and C-G nitrogenous base pairing; single-stranded; base pairing determines 3D shape of the single strand
