DNA STRUCTURE

DNA STRUCTURE

1. Nucleotide structure -All combined through condensation reaction to form dinucleotide-

   • Pentose sugar - Deoxyribose
   • A phosphate
   • An organic base
     • Single Ring- Cytosine & Thymine
     • Double Ring- Adenine & Guanine

2. Pairing of Bases

   • Contain Nitrogen
   • Adenine & Guanine are double ring structures
     • Longer molecules
   • Thymine & Cytosine are single ring stuctures
     • Shorter molecules
   • Adenine is complementary to Thymine.
     • Two hydrogen bonds.
   • Each rung of DNA ladder must be the same length
   • Cytosine is complementary to Guanine.
     • Three hydrogen bonds.

3. Function of DNA

   • Very stable and can pass from generation to generation
   • Strands are joined by hydrogen bonds, allows them to separate during DNA replication and protein synthesis.
   • Carries immense amount of genetic material
   • Deoxyribose-phosphate backbone protects the genetic information from being corrupted by outside chemicals.