1. Chapter 12: Molecular Genetics DNA structure DNA structure Protein synthesis Protein synthesis DNA Replication DNA Replication

2. DNA: The Genetic Material Section 1 – p. 329

3. Warm-up: 1. DNA is what kind of macromolecule? A. Protein B. Lipid C. Carbohydrate D. Nucleic acid 2. The macromolecule, DNA, is made up of which kind of monomers? A. Amino acids B. Fatty acids C. Monosaccharides D. Nucleotides

4. Essential Questions DNA 1.What is DNA? Chargaff’s 2.How can we describe Chargaff’s base pairing rules? chromosome 3.Compare the structure of a eukaryotic chromosome with prokaryote DNA. genes 4.How are genes, chromosomes, and DNA related?

5. The “OLD” People of DNA 1.Fredrick Griffith 2.Oswald Avery 3.Hershey and Chase 4.Erwin Chargaff 5.Watson and Crick

6. Fredrick Griffith-1928  In 1928, British scientist Fredrick Griffith was trying to learn how certain types of bacteria caused pneumonia.  He isolated two different strains of pneumonia bacteria from mice and grew them in his lab.  Performed the first major experiment that led to the discovery of DNA as the genetic material

7.  Transformation  Griffith determined that bacteria could pass genetic information from one to another.  Griffith called this process transformation because one strain of bacteria (the harmless strain) had changed permanently into another (the disease causing strain). But what was the transforming factor?

8. Oswald Avery-1944  Oswald Avery repeated Griffith’s work to determine which molecule was most important for transformation.  Identified the molecule that transformed the R strain of bacteria into the S strain  Concluded that when the S cells were killed, DNA was released  R bacteria incorporated this DNA into their cells and changed into S cells.  Discovered that DNA was the “transforming factor”.

9. Hershey and Chase-1952  Alfred Hershey and Martha Chase studied viruses— nonliving particles smaller than a cell that can infect living organisms.  If Hershey and Chase could determine which part of the virus entered an infected cell, they would learn whether genes were made of protein or DNA  Concluded that the viral DNA was injected into the cell and provided the genetic information needed to produce new viruses  Provided definitive evidence that DNA is the source of genetic material.

10. So Griffith, Avery, Hershey and Chase all helped discover DNA and the importance that it plays in transmitting genes. But what is DNA??? What is it made of??? What does it look like??????

11. Warm-up A nucleotide is made up of three parts. What are they? (Use your book if you like.)

12. What is DNA? 1.A genetic code nucleotides 2.A molecule made of subunits called nucleotides double helix 3.A complex molecule that is arranged as a double helix.

13. NUCLEOTIDES are the smallest units (monomers) of DNA that include: Phosphate group 5-Carbon sugar Nitrogen base

14. NUCLEOTIDES the smallest subunit of DNA

15. Two Kinds of bases in DNA  Pyrimidines are single ring bases.  Thymine & Cytosine  Purines are double ring bases.  Adenine & Guanine Memory trick “Y” are you single?

16. A G C T

17. Erwin Chargaff-  Analyzed the amounts of A, C, T, and G in DNA; Discovered A=T & C=G

18. The Shape of DNA is a Double Helix  DNA often is compared to a twisted ladder.  Rails of the ladder are represented by the alternating deoxyribose and phosphate.  The pairs of bases (cytosine–guanine or thymine–adenine) form the steps.

19. Watson and Crick  Built a model of the double helix that conformed to the others’ research 1. two outside strands consist of alternating deoxyribose and phosphate molecules 2. cytosine and guanine bases pair to each other by three hydrogen bonds 3. thymine and adenine bases pair to each other by two hydrogen bonds

20. Watson and Crick  Suggested the structure for DNA and hypothesized a method of replication

21. Refer to the DNA handout Phosphate groups. P orange. 1.Locate the Phosphate groups. Label each one “P” and color them orange. deoxyribose sugars blue. 2.Locate the deoxyribose sugars and label them. Color all sugars blue. 3.Locate the nitrogen bases and label. 4.Label the hydrogen bonds.

22. DNA Structure Activity 1.Locate the nitrogen bases Adenine and color it purple. 2.Label Adenine and color it purple. Thymine and color it yellow. 3.Label Thymine and color it yellow. Cytosine and color it red. 4.Label Cytosine and color it red. Guanine and color it green. 5.Label Guanine and color it green.

23. 4 Nitrogen Bases Purines are larger bases Pyrimidines are smaller bases Adenine Thymine Guanine Cytosine

24. CHARGAFF’S BASE CHARGAFF’S BASE PAIRING RULES PAIRING RULES A binds with T G binds with C

25. Hydrogen Bonds Fig. 4. Adenine-Thymine base pair with two hydrogen bounds. Fig. 5. Guanine-Cytosine base pair with three hydrogen bounds C = Carbon = grayN = Nitrogen = blueO = Oxygen = red

26. 3-D Animation of DNA http://www.umass.edu/molvis/tutorials/dna/dnapairs.htm

27. Stop & Review 1.What is the smallest subunit of DNA? 2.List 3 parts to #1? 3.What are the side chains of DNA made of? 4.What are the “steps” of DNA made of? 5.What are the base pairing rules of DNA? 6.Describe the structure of DNA in 2 words.

28. ANSWERS 1.Nucleotide 2.Sugar, phosphate, and a nitrogen base 3.Sugar and phosphate 4.Nitrogen base 5.A=T, C=G 6.Double Helix

29. Comparing eukaryote & prokaryote DNA PROKARYOTE Circular EUKARYOTE Linear

30. genes How are genes, chromosomes, and DNA related? Genes are portions of DNA that are tightly packed into chromosomes and code for the manufacture of proteins.

31. genes How are genes, chromosomes and DNA related? Think of chromosomes as socks and genes as stripes on the socks.

32. Place in order from smallest to largest. Gene DNA Chromosomes

33. Vocabulary Clarification CHROMATIN CHROMOSOME

35. Have Your DNA & eat it too! 1.Collect materials 2.Follow instructions green pink *A (green) pairs with T (pink) yellow orange *C (yellow) pairs with G (orange)

37. Warm-up 1. Is DNA double stranded or single stranded? 2.If you are given the DNA sequence ATCCGTTAC, what would be the sequence of the complementary strand?