Chapter 11: DNA

1
Chapter 11DNA the Language of Life
2
11.1 Genes are made of DNA

• Review
• 1928 Griffith used bacteria in mice to discover
  transforming factor
• 1944 Avery found the factor was DNA
• 1952 Hershey Chase proved Averys theory using
  viruses and bacteriophages

3
11.2 Nucleic Acids store information

• Deoxyribonucleic Acid
• Nucleotides - building blocks
• Three parts
• 1) ring-shaped sugar (deoxyribose)
• 2) phosphate group
• 3) nitrogen base

4
11.2 Nucleic Acids store information

• Four nucleotides exist depending on bases
• Pyrimidines (single ring)
• Thymine (T)
• Cytosine (C)
• Purines (double ring)
• Adenine (A)
• Guanine (G)

5
11.2 Nucleic Acids store information

• Covalent bonds join nucleotides as backbone
• Sugar-phosphate-sugar

6
11.2 Nucleic Acids store information

• 1950s Franklin took DNA Xray pictures
• Showed helical shape
• Watson Crick found bases paired by hydrogen
  bonds
• A with T, C with G
• Forms a double helix

7
Concept Check

• Q Given the one strand of a DNA double helix
  shown, what are the bases on the complimentary
  section of the other strand of DNA?
• A CGATAGCAG

Start here