Unit 9 Part 1 DNA

I. Griffith and Transformation (1928) A. Griffith wanted to know how (which) bacteria caused pneumonia B. Isolated 2 strains of bacteria 1. Smooth bacteria- caused pneumonia 2. Rough bacteria- did not cause pneumonia

C. Experiment 1. Smooth bacteria- injected into mice 2. Rough bacteria- injected into mice mice die mice live

3. Heat killed smooth bacteria- injected into mice 4. Mixed heat killed smooth bacteria with rough bacteria- injected into mice mice live mice die X X

5. Conclusion: The rough (harmless) strain of bacteria had been transformed into the disease-causing strain. A transformation had occurred. 6. Griffith thought the transforming factor might be a gene.

Experiment 3 Experiment 4 Experiment 1 Experiment 2 Heat killed smooth Inject mouse with _______________ bacteria Inject mouse with ________________ And ____________ bacteria Inject mouse with ________bacteria Inject mouse with ________bacteria Heat killed smooth Heat killed smooth rough smooth rough Lives  Dies  Lives  Dies  Mouse _________ Mouse _________ Mouse _________ Mouse _________

Notes: Unit 9 Part 2

II. Avery (1944) Wanted to determine what type of molecule was responsible for the transformation, the molecule that makes up genes. B. Repeated Griffith’s experiments C. Made an extract (solution) of heat killed smooth bacteria and rough bacteria

D. Added 5 different enzymes to the bacteria extract (enzymes that destroy different organic compounds) 1. Bacteria Extract + Protein destroying enzymes = transformation occurred (mouse alive or dead?) 2. Bacteria Extract + Lipids destroying enzymes = transformation occurred (mouse alive or dead?) 3. Bacteria Extract + Carb destroying enzymes = 4. Bacteria Extract + RNA destroying enzymes = 5. Bacteria Extract + DNA destroying enzymes = transformation DID NOT OCCUR (mouse alive or dead?)

E. Avery's Conclusion- DNA was the Transforming factor.

III. Hershey and Chase (1952) Wanted to know if genes were made of proteins or DNA? B. Used bacteriophages (phages)- a type of virus that attack bacteria. 1. Phage injects its genetic material into bacteria and uses the cell to reproduce more phages 2. Kills bacteria cell- releasing hundreds of phages

C. Used radioactive markers 1. sulfur 35 2. phosphorous 32 **Remember what elements are in A. proteins? B. Nucleic Acids ( DNA)? C H O N S C H O N P

1. Bacteria with phages with either a. radioactive phosphorus OR D. Mixed: 1. Bacteria with phages with either a. radioactive phosphorus OR b. radioactive sulfur 2. Found: radioactivity in bacteria with Phage DNA injected was from phosphorous only. E. Hershey and Chases conclusion: Genes of phages are made of DNA not proteins. http://nortonbooks.com/college/biology/animations/ch12a02.htm

Cut out Glue at the top of page 8 DNA Structure (Unit 9.3) With double helix or twisted ladder PAGE 8 Cut out Glue at the top of page 8

A. DNA= Deoxyribonucleic acid Write in your notebook: A. DNA= Deoxyribonucleic acid *REMEMBER: nucleic acids are organic molecules.

Cut out Glue on page 8 towards middle Color each piece a different color

B. The building blocks of DNA are NUCLEOTIDES 1. Nucleotides consist of 3 parts. a. Deoxyribose (5-Carbon sugar) b. Phosphoric acid c. Nitrogen Base (one of 4)

The Four Nitrogen bases are i. Adenine (purine=2 rings) ii. Guanine (purine=2 rings) iii. Cytosine (pyrimidine=1 ring) iv. Thymine (pyrimidine=1 ring)

Lets practice! Cut and glue the DNA strand onto page 8 Color code the DNA strand to match the other image

Write below images on page 8: Chargaff’s Rules Studied nucleotide composition B. He found out through research: 1. Amount of A=T 2. Amount of C=G C. This pattern has proven true for almost every organism

Chargaff’s Rules

Glue on page 9 and color code: Write on page 9 BASE PAIR RULES 1.Guanine<-->Cytosine 2.Adenine<-->Thymine

Let’s Practice Glue this image and color code and label this DNA strand

3.The pairing of nitrogen bases is called base pairs.

Get a clean ½ sheet of paper Fold hamburger style *you may have to trim the open edge so it fits

VI. Rosalind Franklin-1951 A. Studied DNA molecule with X-ray diffraction. B. X-ray diffraction: powerful X-ray beam aimed at a sample and scattering pattern recorded on film. Front of flap book

C. Franklin’s pattern suggested DNA was 1. 2 strands Front of flap book C. Franklin’s pattern suggested DNA was 1. 2 strands 2. Strands twisted around each other 3. Nitrogen Bases are in center D. Maurice Wilkins- lab assistant

VII. Watson & Crick- 1953 A. Wanted to understand structure of DNA. Inside top of flap book A. Wanted to understand structure of DNA. B. Used clues from Franklin’s images C. Used Chargaff’s rules to determine the strands are complimentary. A-T and C-G D. Built model to show: 1. How DNA carries info 2. How DNA makes copies.

VIII. Watson & Crick- 1953 continued… Inside bottom of flap book VIII. Watson & Crick- 1953 continued… E. They discovered that hydrogen bonds could form between: 1. Adenine (A) & Thymine (T) 2. Guanine (G) & Cytosine (C) F. Structure = DOUBLE HELIX

D. Watson, Crick and Wilkins are awarded the Nobel Prize in 1962 for the discovery of the structure of DNA.

½ sheet of paper Glue to bottom of page 9