deoxyribonucleic acid (DNA)

Function

• contains blueprint for reproduction & other cellular functions
• in coding regions, DNA is transcribed into RNA
  • rRNA
  • tRNA
  • mRNA
  • siRNA: at least some siRNA may derive from pre-mRNA transcripts
• within a protein-coding gene, the sequence of nucleotides (group of 3 - codon) determines the sequence of amino acids in the protein it encodes
• non-coding regions perform essential functions
  • promoters & enhancer elements that regulate gene expression
  • sequences of DNA are needed for tertiary structure, attachment to the nuclear matrix, for initiation of DNA replication, for formation of centromeres ...
  • 80% of human DNA is transcribed into small RNA segments that control gene expression
  • 8% of human DNA is derived from viruses

Structure

• nucleotides consist of deoxyadenosine, deoxycytidine, deoxyguanosine and deoxythymidine where the base is adenine, cytosine, guanine and thymine respectively
• two antiparallel polynucleotide chains arranged in right handed double helix, with nucleotide bases associated by hydrogen bonds - adenine (A) associates with thymine (T) and cytosine (C) associates with guanine (G)

Compartment

• in eukaryotes, DNA residues in nucleus & mitochondria

More general terms

• polynucleotide

More specific terms

• complementary DNA (cDNA)
• double-strand DNA (ds DNA)
• gene
• gene cluster
• mitochondrial DNA
• Okasaki fragment
• pseudogene
• replicon
• ribosomal DNA
• satellite DNA
• single-strand DNA (ss DNA)
• transposon (jumping gene, transposable element, mobile genetic element, selfish DNA)

Additional terms

• codon (triplet)
• DNA (genetic) testing
• DNA damage
• DNA methylation (promoter methylation)
• DNA repair
• DNA synthesis