DNA

• How are POLYNUCLEOTIDES formed ?

  CONDENSATION REACTION
• What are the bonds between PHOSPHATE GROUP and CARBON 5 ?

  PHOSPHODIESTER BONDS
• DNA STRUCTURE

  • DOUBLE-STRANDED, ALPHA DOUBLE HELIX with a SUGAR PHOSPHATE BACKBONE on each STRAND
• What bonds are between the BASES ?

  HYDROGEN BONDS
• What bonds hold the STRUCTURE together ?

  HYDROGEN BONDS
• Structure of the BASES

  • PURINE (2 NITROGEN-containing RINGS): ADENINE, GUANINE
  • PYRIMIDINE ( 1 NITROGEN -containing RINGS):  CYTOSINE, THYMINE
• SUGAR

  DEOXYRIBOSE(hydroxyl group REPLACED by HYDROGEN on CARBON - 2 )
• mRNA STRUCTURE

  • SINGLE - STRANDED, not usually folded, carries CODONS (triplets of bases) which ATTACH to tRNA via HYDROGEN BONDS
• tRNA STRUCTURE

  • SINGLE - STRANDED, FOLDED into a SPECIFIC PATTERN held together by HYDROGEN BONDS, carries ANTICODONS COMPLEMENTARY to mRNA CODONS, bonded via HYDROGEN BONDS