All sections February 25, 2010

1. All sections February 25, 2010 Objective: To learn about the basic building block of life  DNA Vocab (put in vocab section of your notebook): Deoxyribonucleic acid, phosphate, sugar, nucleotide, adenine, cytosine, thymine , guanine Check Yourself: In our last class we: Discussed whether or genetic code should be made available to everyone *SOCIAL SCIENTIST ASSISTANCE!! Warm Up: What are the various parts of your DNA?

2. GENES  CHROMOSOMES  DNA for ALL!

3. DNA(Deoxyribonucleic Acid)

4. Genetic material of cells… • GENES – units of genetic material that CODES FOR A SPECIFIC TRAIT • Called NUCLEIC ACIDS • DNA is made up of repeating molecules called NUCLEOTIDES

5. Phosphate Group O O=P-O O 5 CH2 O N Nitrogenous base (A, G, C, or T) C1 C4 Sugar (deoxyribose) C3 C2 DNA Nucleotide

6. A HISTORY OF DNA • Discovery of the DNA double helix A. Frederick Griffith – Discovers that a factor in diseased bacteria can transform harmless bacteria into deadly bacteria (1928) B. Rosalind Franklin- X-ray photo of DNA. (1952) C. Watson and Crick- described the DNA molecule from Franklin’s X-ray. (1953)

7. Watson & Crick proposed… • DNA had specific pairing between the nitrogen bases: • ADENINE – THYMINE • CYTOSINE - GUANINE • DNA was made of 2 long stands of nucleotides arranged in a specific way called the “Complementary Rule”

8. “Rungs of ladder” Nitrogenous Base (A,T,G or C) “Legs of ladder” Phosphate & Sugar Backbone DNA Double Helix

9. 5 O 3 3 O P P 5 5 C O G 1 3 2 4 4 2 1 3 5 O P P T A 3 5 O O 5 P P 3 DNA Double Helix

10. A or G T or C Nitrogenous Bases • PURINES 1. Adenine (A) 2. Guanine (G) • PYRIMIDINES 3. Thymine (T) 4. Cytosine (C)

11. C T A G Chargaff’s Rule • Adeninemust pair with Thymine • Guanine must pair with Cytosine • Their amounts in a given DNA molecule will be about the same.

12. H-bonds G C A T BASE-PAIRINGS

13. DNA Modeling Activity • Instructions 1. Line the borders of your strip of paper with circles (that are not touching and makes the paper look like a long domino) (What do these colors on the outside of your DNA molecule represent?)

14. CONGRATULATIONS – YOU HAVE CREATED THE BACKBONE OF THE DNA MOLECULE! • 2. Draw pentagons closer to the middle and between each circle. (What do these represent?) • 3. Connect the circles on one side to the pentagons on the same side nearest them

15. Now write the story • 4. Write the letters A, G, T, or C closer to the center (but not on center) and a little ahead of the Sugars on one side of your paper (in any order you choose) (What do these letters represent?) 5. And connect them to the sugars

16. 6. Now finish the code by writing in the corresponding nucleotide across from the ones you have chosen! • 7. And connect G to C with three bonds and A to T with two bonds (Which type?) (What type of bond do these lines represent?

17. HW – bring in the (basic) material you need for a pilot run of your science fair project… • Check power school and ensure you find the grade I have zeroed

18. Open NBK quiz (you have 5 minutes) Directions: In your notebook, clearly ANSWER (only) the following questions. 1. What does DNA stand for? (1 pt) 2. What are the 3 parts of each nucleotide? (3 pts) 3. What are the different possible nitrogenous bases? (4 pts)

19. Objective: To learn about how DNA is replicated and transcribed

20. Genetic Diversity… • Different arrangements of NUCLEOTIDES in a nucleic acid (DNA) provides the key to DIVERSITY among living organisms.

21. The Code of Life… • The “code” of the chromosome is the SPECIFIC ORDER that bases occur. A T C G T A T G C G G…

22. DNA is wrapped tightly around histones and coiled tightly to form chromosomes

23. DNA Replication • DNA must be copied • The DNA molecule produces 2 IDENTICAL new complementary strands following the rules of base pairing: A-T, G-C • Each strand of the original DNA serves as a template for the new strand

24. DNA Template Parental DNA New DNA DNA Replication • Semiconservative Model: 1.Watson and Crick showed: the two strands of the parental moleculeseparate, and each functions as a template for synthesis of a new complementary strand. .

25. Activity – Try it

26. Replication Quiz 1. Why is replication necessary? 2. When does replication occur? 3. Describe how replication works. • Use the complementary rule to create the complementary strand: A---? G---? C---? T---? A---? G---? A---? G---? C---? A---? G---? T---?

27. Replication Quiz 1. Why is replication necessary? So both new cells will have the correct DNA 2. When does replication occur? During interphase (S phase). 3. Describe how replication works. Enzymes unzip DNA and complementary nucleotides join each original strand. 4. Use the complementary rule to create the complementary strand: A---T G---C C---G T---A A---T G---C A---T G---C C---G A---T G---C T---A

28. (1961) Watson & Crick proposed… • …DNA controlled cell function by serving as a template for PROTEIN structure. • 3 Nucleotides = a triplet or CODON (which code for a specific AMINO ACID) • AMINO ACIDS are the building blocks of proteins.

29. DNA Transcription • DNA can “unzip” itself and RNA nucleotides match up to the DNA strand. • Both DNA & RNA are formed from NUCLEOTIDES and are called NUCLEIC acids.

30. DNA and RNA DNA RNA C, G, A, U URACIL Contained in the Nucleus and Cytoplasm Single Strand (less stable) • C, G, A, T • THYMINE • Contained in the Nucleus • Double Strand (more stable)

31. Activity – Try it Rules • DNA is transcribed with the help of transcription factors that bind to specific sites on the DNA • Transcription factors generally show where to start or stop transcription Our transcription factor will • initiate transcription at the 3rd, 4th and 5th nitrogenous base in your DNA • Terminate transcription at the 14th nitrogenous base

32. DNA Translation • Happens outside of the nucleus in the cytoplasm • The cell uses information from “messenger” RNA to produce proteins • Ribosomes help amino acids attach in anti-codon sequences to the mRNA • The process is controlled by start and stop codes • Amino acids are the building blocks for proteins

33. IMAGES TO ASSIST

34. G a ugg u a u c g u g c a uu g c a UAGc c a u u met V A L S E R C Y S I LE A L A STOP Sequence 1 – Human (template strand) C T A C C A T A G C A C G T A A C G T AT C G G T A A RNA : Amino Acids: PRACTICe

35. Try it Find the start codon on your mRNA (AUG) (If you do not have one or if it as the very end change your first three nitrogenous bases to AUG for this practice) Start using the tRNA (little paper strips) for each codon and attach the amino acid (paper clips) to build your protein Continue until you come to the STOP codon (UAG, UAA, UGA) (if you do not have a stop codon then change the last codon to say UAG, UAA or UGA) 4. Record the amino acid sequence of your protein.

36. Transcription/Translation Quiz • Why is transcription necessary? • Describe transcription. • Why is translation necessary? • Describe translation. • What are the main differences between DNA and RNA. • Using the chart on page identify the amino acids coded for by these codons: UGGCAGUGC

37. 1. Why is transcription necessary? Transcription makes messenger RNA (MRNA) to carry the code for proteins out of the nucleus to the ribosomes in the cytoplasm. 2. Describe transcription. RNA polymerase binds to DNA, separates the strands, then uses one strand as a template to assemble MRNA. 3. Why is translation necessary? Translation assures that the right amino acids are joined together by peptides to form the correct protein.

38. 4. Describe translation. The cell uses information from MRNA to produce proteins. 5. What are the main differences between DNA and RNA. DNA has deoxyribose, RNA has ribose; DNA has 2 strands, RNA has one strand; DNA has thymine, RNA has uracil. • Using the chart on page 303, identify the amino acids coded for by these codons: UGGCAGUGC tryptophan-glutamine-cysteine

39. AMAZING DNA FACTS… • DNA from a single human cell extends in a single thread for almost 2 meters long!!! • It contains information equal to some 600,000 printed pages of 500 words each!!! (a library of about 1,000 books)

40. You Tube Clip Links • Replication • http://www.youtube.com/watch?v=vJSmZ3DsntU • Transcription • http://www.youtube.com/watch?v=rpwjZX_z5rg&feature=channel • Translation • http://www.youtube.com/watch?v=SghWl3MVbAI

41. So now we’ve learned how to make proteins • What do they do? • What are they good for?

44. 1. MUTATIONS! • This is when something goes wrong!!!

46. Point mutations: Single base mutations: 1. Missense mutation: leads to an amino acid change 2. Silent mutation: does not change the amino acid 3. Nonsense mutation: causes premature stop-codon

47. Frameshift mutations: • insertion/deletion • dublication • translocation • Altered reading frame • Severe impacts on protein structure

50. Albinism - Mutation