Organic compounds - Nucleic Acids

General Properties:

• Two types of nucleic acids: DNA and RNA
• Both are polymers of nucleotides.
• Nucleotides consisting of nitrogenous bases, phosphate group, pentose (5 C sugar)

Nitrogenous bases

• The sequence of the 5 nitrogenous bases, determines unique structure of DNA and RNA.
• Pyrimidines (6 member ring)
  • Cytosine
  • Thymine (DNA only)
  • Uracil (RNA only)
• Purines (6 member ring + 5 ring)
  • Adenine
  • Guanine

Deoxyribonucleic Acid (DNA)

• Polynucleotide formed by bonds between sugar and phosphate (sugar-phosphate backbone).
• Nitrogenous base sticks out of the strand.
• DNA exists as two strands wrapped around each other (double helix).
• N-bases connect with another sugar-phosphate backbone strand.
• A pyrimidine always connects to a purine.
  • Adenine with thymine (A - T)
  • Guanine with cytosine (G - C)
• The sequence of the 5 N-bases, determines unique structure of DNA.

Ribonucleic Acid (RNA)

• Like DNA: polynucleotide with nitrogenous bases sticking out sugar-phosphate backbone strand.
• RNA exists as a single sugar-phosphate backbone strand.
• Also uracil replaces thymine