Structure of DNA & RNA

• Nucleotide structure:

  • Pentose sugar
  • Phosphate molecule
  • A nitrogenous base
• Type of reaction that forms a nucleotide?

  Condensation
• What is the bond formed between two mononucleotides?

  Phosphodiester bond
• Ribonucleic acid (RNA) structure:

  • short
  • pentose sugar is ribose
  • bases are adenine, uracil, guanine and cytosine
  • types are tRNA, mRNA and rRNA
• Deoxyribonucleic acid structure (DNA)

  • the Pentose sugar is deoxyribose
  • bases are adenine, thymine, guanine and cytosine
  • double helix
• Stability of DNA:

  • The phosphodiester backbone protecrs the organic bases
  • Hydrogen bonds link the bases together
  • there are 3 hydrogen bonds between guanine and cytosine
  • there are 2 hydrogen bonds between adenine and thymine
  • the most C+G pairings the more stable the molecule
• Function of DNA:

  • barely any mutations occur
  • hydrogen bonds allow bases to separate
  • large molecule so carries a lot of genetic information
  • base pairs are protected