1. New Seating Chart Today! Be ready to pack up and move… Deoxyribonucleic Acid Biology Journal 10/14/2013 What are the 4 most commonly occurring elements in living things? What do the letters in the acronym DNA stand for? Carbon, Hydrogen, Oxygen, Nitrogen What 5 elements are found in DNA? Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous

2. Mr. Gatewood is accepting IB test registration and payment through this Friday. • Come see him if you need any guidance on which tests to take. • Come see him if you would like to test, but are having trouble coming up with the fees.

3. 3.3 DNA Structure

4. DNAyeeeeeee

5. A C Review! Disaccharide Disaccharide What do you call these types of carbohydrates? B D Monosaccharide Polysaccharide

6. A C Review! Lactose Sucrose What is the name of these carbohydrates? B D Ribose Starch

7. Review! → + H2O + What are the reactants of this reaction? 2 glucose molecules. What are the products of this reaction? Lactose and water. What kind of reaction is this? It is a condensation synthesis (it’s called condensation because water is made from the OH and H groups of the reactants)

8. Deoxyribose: a monosaccharide, or “sugar.” C5H10O4. The Parts of DNA

9. What is the difference between ribose and deoxyribose? Ribose Deoxyribose C5H10O4 C5H10O5

10. Phosphate: PO4 The Parts of DNA

11. Deoxyribose and phosphate alternate to make up the “sugar-phosophate backbone.” The Parts of DNA

12. The bases (aka nitrogenous bases, aka nucleic acids, aka nucleotides) • Adenine, cytosine, thymine, guanine The Parts of DNA

13. Review! What is a hydrogen bond? Hydrogen bonds are attractions between positive and negative sides of molecules.

14. A always pairs with T • C always pairs with G

15. A and G are larger, 2-ringed bases. • T and C are smaller, 1-ringed bases.

16. Thus, every base pair consists of a 1-ringed base and a 2-ringed base. How might this help find and correct errors (mutations) in DNA?

17. A and T are joined by 2 hydrogen bonds. • G and C are joined by 3 hydrogen bonds. How might this help find and correct errors (mutations) in DNA?

18. DNA Can be represented in many ways…

19. Which of the following are not found in pairs? Adenine and Thymine Dookies Twins Thymine and Cytosine Aces

20. Deoxyribose Phosphate A T G C Hydrogen bonds

21. Where’s the base pairs? Where’s the backbone?

22. The double helix is a twisted ladder shape that helps the DNA take up less space.

23. Histones are a protein that the DNA wraps around to take up less space The way that DNA wraps around histones is called the “pearl necklace” shape.

24. Histones are like little stones that the DNA wraps around. How long would this ball of yarn be if it wasn’t wrapped around something?

25. Histones are a protein. What is another word for a protein? What are proteins made out of?

26. 3.3 DNA Structure

27. Biology Journal 10/15/2013 DNA is a huge molecule! There are 2 ways in which DNA compacts itself to take up less space. What are they?

28. Biology Journal 10/15/2013 Standard 3.3.5 is “Draw and label a simple diagram of the molecular structure of DNA.” Can you do it?

29. 3.3 DNA Replication

30. The two strands of DNA can be separated, called unzipping. • Remember, the 2 strands are connected by hydrogen bonds, which are much weaker than covalent bonds.

31. DNA Helicase is the enzyme that does the unzipping. DNA Helicase un-does the double helix.

32. In college, all the cool kids wear ironic, pun-driven science t-shirts

33. DNA Helicase Simplified model

34. DNA Helicase Space-filling model

35. DNA Helicase Model showing -helixes and -sheets.

36. DNA unzips during replication (when DNA copies itself)

37. When do you think your cells would replicate their DNA? Your cells replicate their DNA before they divide to make new cells. They do this… • For routine replacement of cells (such as skin cells, blood cells, stomach cells, etc) • When you grow or gain weight • When you are injured and need to replace dead cells

38. If one strand of DNA has these base pairs, then what are the base pairs on the complementary strand? CTAATCGTATATAGTCC GATTAGCATATATCAGG

39. In replication…DNA helicase unzips DNA.DNA polymerase adds in the complementary (matching) bases to each single strand, creating 2 identical strands.

43. When DNA replicates, the new DNA molecules both consist of one new strand and one original strand. This is called semi-conservative replication.

44. It took scientists a while to figure out that DNA replication was semi-conservative, as opposed to some other pattern.

45. Your assignment: • Show DNA replication using the pieces provided. • Show at least 3 base pairs in the “starting DNA” • Show at least 2 base pairs in each “new strand of DNA” • Label: • Parent strand of DNA and New strands • DNA helicase • DNA polymerase • Hydrogen bonds • Each of the molecules in DNA (deoxyribose, phosphate, cytosine, adenine, guanine, thymine) • Define the job of: • DNA helicase • DNA polymerase

46. Biology Journal 10/15/2013 DNA helicase: unzips DNA, making 2 single-strands. DNA Polymerase: adds in new complementary bases (and backbone) to each single strand, making 2 complete copies of DNA. What are the names of the two most important enzymes in DNA replication? What does each one do?

48. DNA Biology Journal 10/17/2013 What do you end with? 2 sets of the original DNA (through semi-conservative replication) In DNA replication, what do you start with? What is the purpose of replication? When cells divide, each new cells needs a full set of DNA.

49. DNA Replication • DNA helicase unzips the DNA • DNA polymerase connects together matching bases to make 2 new strands. Making a copy

50. 3.3 Transcription and Translation