Structural Components and Types of DNA

Structural Components of DNA

• Sugar Component:
  • Deoxyribose sugar forms the sugar backbone.
• Nitrogenous Bases:
  • Includes nitrogen bases listed as A, G, and J.C.

Classification of DNA Based on Shape

• Circular DNA:
  • Definition: A type of DNA which does not have a free end.
  • Cellular Location: Found mainly in prokaryotic cells as well as inside cell organelles, specifically the chloroplast and mitochondria of eukaryotic cells.
• Linear DNA:
  • Definition: A type of DNA which has free ends.
  • Cellular Location: Found in eukaryotic cells.

Classification of DNA Based on Nitrogen Base Pairs

• A-DNA:
  • Contains $11$ base pairs (or $1$ base pair) in one complete turn.
  • Structural form: Right-handed duplex (also referred to as might-handed duplex).
• B-DNA:
  • Contains $10$ base pairs in one complete turn.
  • Structural form: Right-handed duplex.
• C-DNA:
  • Contains $9$ base pairs (indicated as $I$ base pair) in one complete turn.
  • Structural form: Right-handed duplex.
• D-DNA:
  • Contains $8$ base pairs in one complete turn.
  • Structural form: Right-handed duplex.