+ Frederick Griffith Studied: Better way to fight pneumonia Experiments: Smooth bacteria=dead mouse. Rough bacteria = alive mouse. Heat killed smooth= live mouse Heat killed smooth + rough=Dead mouse Conclusions: Some molecules or group of molecules changed the harmless rough bacteria into deadly smooth bacteria. Called transformation

+ Frederick Griffith Your tasks: Answer the following questions in your notes booklet. Griffith tried to find a better way to fight ____________ What is Transformation? Fill in Griffith’s information on your scientist chart in your notes booklet.

+ Avery Studying: Process of transformation as a key to finding heredity Experiments: Repeated Griffith’s experiment: Treated heat-killed smooth with enzymes that destroyed either proteins, lipids, carbohydrates, RNA. None affected transformation. When DNA was destroyed transformation was blocked. Conclusions: Genes are made of DNA

+ Avery Your Tasks: Answer the following questions in your notes booklet: Avery was trying to figure out the key to heredity, he discovered Genes are made up of __________ Fill in Avery’s information on your chart in your notes booklet.

+ Hershey & Chase Studying: Skeptical of Avery’s conclusion. Wanted more support Experiments: Bacteriophage- virus infects bacteria. Knew viruses made of protein & DNA. Used radioactive isotopes to mark them Protein-sulfur-35, DNA-phosphorus-32 Found phosphorus-32 in bacteria Conclusions: Genetic material is DNA, not protein

+ Hershey & Chase Your Tasks: Answer the following questions in your notes booklet: Hershey & Chase didn’t believe Avery they though Genetic material was made up of ___________ not DNA. Where they right??? __________ Fill in Hershey & Chase’s information in your chart in your notes booklet.

+ Chargaff Studying: Studied nucleotide composition in DNA Experiments: Showed that there was the same amount of adenine & thymine, and cytosine & guanine Conclusions: Chargaff’s rule: Always!! A-T C-G

+ Chargaff Your Tasks: Answer the following questions in your notes booklet: Chargaff noticed that every time there was the same amount of Adenine and _________ ; the same amount of Cytosine & ____________ Write a way to remember A-T and C-G: ____________________________________________ Fill in Chargaff’s information in your chart in your notes booklet.

+ Franklin Studying: Studied DNA using x-ray diffraction Experiments: Powerful x-ray beams is aimed at a sample, then the scattering pattern of the x-ray is recorded on the film Conclusions: By itself does not reveal the structure of DNA SHE WAS CHEATED OUT OF THE PRIZE!!!

+ Franklin Your task: Answer the following questions in your notes booklet: Franklin was trying to discover the shape of ________ by using ____________________ Why didn’t she win the Nobel Prize? Enter Franklin’s information into the chart in your notes booklet.

+ Watson & Crick Studying: What is the structure of DNA? What held the two strands together? Experiments: Analyzed other scientists’ work. Few weeks after Franklin’s x-ray experiments- they solved the puzzle of the structure of DNA. Made sketches & built models Conclusions: Two strands twisted around one another Double Helix Hydrogen bonds between the bases *1962-Watson & Crick Won Nobel Prize - discovered structure of DNA

+ Watson & Crick Your Task: Answer the following questions in your notes booklet: Watson & Crick get the credit for discovering the shape of DNA is a ________________ Fill in Watson & Crick’s information into your chart in your notes booklet.

+ DNA Structure The Monomer of DNA is a Nucleotide Nucleotides consist of : 1)Phosphate Group 2)5 Carbon sugar deoxyribose 3)A nitrogen base Weak Hydrogen bonds join nucleotides between nitrogen bases Strong Stable Covalent bonds holds each part of the nucleotide together.

+ DNA Structure Your Task: Answer the following questions in your notes booklet: What is the Monomer of DNA? _______________ What are the 3 parts of a Nucleotide? Draw & Color code the Monomer of DNA What type of bonds hold one nitrogen base to the other nitrogen base? __________ Are the strong or weak? What type of bonds hold the phosphate group to the deoxyribose sugar? _________________ Are they strong or weak?

+ DNA Structure The 4 Bases of DNA (A)denine-(C)ytosine (T)hymine- (G)uanine These chains form a DOUBLE HELIX (like a twisted ladder) Only specific pairs of bases bond together A bonds to T(Ash Tray / Garbage Can) C bonds G

+ DNA Structure Your Task: Answer the following questions in your notes booklet: Draw the nitrogen bases as puzzle pieces and attach the correct puzzle pieces to each other What is chromatin? What is DNA Replication?

+ DNA Replication STEPS OF DNA REPLICATION 1. Double helix untwists, enzyme “Helicase” breaks the H bonds, 2 nucleotide chains begin to separate like a zipper. 2. Each ½ serves as a pattern for the formation of a new DNA chain. 3. Free nucleotides in the nucleus join with the correct bases. (Chargaff’s BASE PAIRING RULE) 4. The enzyme DNA polymerase bonds the phosphates and sugars of the nucleotide together new molecules of DNA (each contain an original & a new strand) become twisted and take the form of a Double Helix The 2 new DNA molecules are now called “Sister Chromatids” and remain stuck together until the cell divides.

+ DNA Replication Your Task: Answer the following questions in your Notes booklet: Draw what DNA looks like when it untwists and starts to replicate. What enzyme untwists DNA? What is Chargaff’s Rule? What enzyme bonds phosphates and sugars together? Summarize the steps to DNA replication in short 4 – 5 word descriptions. Ex: Step 1: Helicase untwists the Double Helix