Nucleic Acid Structure and Function

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Nucleic Acid Structure and Function
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Function of DNA (DeoxyriboNucleic Acid)

• Contains sections called genes that code for
  proteins.
• These genes are what are passed on from parent to
  offspring.

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Structure of DNA

• Discovered by James Watson (US) and Francis Crick
  (UK) in 1954.
• Described the structure as a double helix

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The Double Helix

• A twisted ladder

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DNA is easier to view in its unwound shape

• A ladder with split rungs

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Nucleotides are the Building Blocks of Nucleic
Acids

• There are 3 parts of the nucleotide
• 5-Carbon (Pentose) Sugar
• Phosphate
• Nitrogen base

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Nucleotide Structure
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Sugar and Phosphate make the sides of the ladder
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Nitrogen Bases make up the rungs of the ladder
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Nitrogen Bases

• Broken down into 2 groups
• Double Ring Bases
• Adenine
• Guanine
• Single Ring Bases
• Cytosine
• Thymine

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Complementary Bases

• Complementary Bases that pair to form a hydrogen
  bond
• A T
• G C

Hydrogen bond
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Molecular Structure

• Besides being twisted, the two strands of DNA run
  in opposite directions

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A 3-Rung DNA molecule