2. Chapter 10

3. Proteins were thought to carry genetic information Fred Griffith 1928 Experimented with pneumonia on mice Virulent (causes sickness) Non-Virulent (does not cause sickness)

4. Proves the genetic material is not Protein Protein Denatures (breaks down) in heat

5. Experiment- Video on Wikispace

8. Adenine = A Guanine = G Cytosine = C Thymine = T The Four Nitrogen Containing Bases found in DNA are divided into two groups: Purines and Pyrimidines

9. Purines Two ringed bases Adenine and Guanine Pyrimidines One ringed bases Thymine and Cytosine

10. In 1953, James Watson and Francis Crick suggested a model for the structure of DNA. This shape is called a double helix Watson and Crick relied heavily on scientific evidence reported by other scientists to construct a model. The model was inspired in part by X-Ray photographs of DNA crystals studied by Rosalind Franklin and Maurice Wilkins.

12. The model provided an explanation for how DNA could be copied and how genetic material might be stored. In 1962, Watson, Crick, and Wilkins received the Nobel Prize in Medicine for their work on DNA. Rosalind Franklin had died and was not recognized. The form of DNA that is most commonly found in living organisms has a right hand twist, with each full turn consisting of ten base pairs.

13. Chargaff: Discovered that A=T and G triple bond C Wilkins & Franklin: Used x-rays to photograph DNA Watson & Crick: First model of DNA

14. Base Pairing Rules (Chargaff’s Rule) Cytosine pairs with Guanine C triple bond G Adenine pairs with Thymine A double bond T Bases are held together by hydrogen bonds EXAMPLE: TCGAATACG What is the complementary strand??

15. - DNA is found in the nucleus of all cells -Found as strands, known as chromatin, in resting cells -Just before cell division, chromatin forms chromosomes. -GENES: are short segments of DNA that contain specific information for traits

17. 1.Control of cells activities 2. Chooses the type of proteins to be made

18. Process of making new copies of DNA 1.DNA untwists 2. An enzyme, DNA Helicase, “unzips” the DNA at the nitrogen bases - breaking hydrogen bonds

19. 3. Free nitrogen bases from the nucleoplasm attach to the newly exposed sections of DNA Done by using DNA Polymerase.

21. DNA Polymerase only works in 5’  3’direction Polymerase moves along the leading strand Fragments are added in segments of the lagging strand Okazaki Fragments

22. 4. The bases are now reattached The result is two DNA strands. 1/2 of the old DNA and 1/2 of the new

23. Replication occurs rapidly because DNA is unzipped in many places at a time.

24. STATISTICS: 46 Chromosomes/cell Approximately 6 billion base pairs/cell Code would fill ½ million pages of books Takes a few hours

25. Proof Reading Average of one error/billion nucleotides Mistakes in replication are check and corrected by specialized “proof- readers” Consists of 20 or so amino acids WHAT TYPES OF THINGS COULD CAUSE CHANGES IN OUR CELLS AFTER REPLICATION?

26. * DNA has the “blueprints” for traits *Too big to pass through the nuclear membrane/pores -Use RNA - ribonucleic acid Parts of the RNA molecule: 1. -sugar 2. -phosphate 3. -nitrogen bases (4) Adenine Uracil Cytosine Guanine 4. RNA is single strand RNA STRUCTURE/TRANSCRIPTION

28. 3 Types of RNA 1. Messenger RNA: carries code from DNA 2. Transfer RNA: single folded strand of RNA that carries the amino acids 3. Ribosomal RNA: major component of ribosome’s.

29. TRANSCRIPTION: Process of transcribing or copying the specific sequence of bases or code from DNA to RNA DNA is considered to be a TEMPLATE

31. 1. An enzyme, RNA polymerase, unzips DNA

32. 2. Free floating RNA nucleotides line up with the appropriate DNA base

33. 3.Continues until the RNA comes to a “stop” sequence and releases the DNA 4. RNA moves out of cell nucleus

35. - Defined as the formation of proteins using information coded on the DNA and carried out by RNA - Proteins may consist of hundred or thousands of amino acids - They are connected by peptide bonds

37. -20 amino acids are found within our bodies -Proteins are read as CODONS

39. Process of making proteins from the mRNA Also referred to as PROTEIN SYNTHESIS Occurs at the Ribosomes 1. mRNA passes out of the nucleus through the nuclear membrane and moves to a ribosome

40. 2. The mRNA attaches to the ribosome at the start codon, (at the P site) 3. The start codon is always “AUG”

41. 4. The mRNA is read in a series of three (3) nitrogen bases at a time - referred to as CODONS. 5. Ribosome signals the tRNA with the matching ANTICODON to bring in the appropriate Amino Acids

42. 6.The tRNA at the “P-site” is released, but the one at the “A-site” stays 7.The ribosome moves to open up the A site

43. 8. The Amino Acids bond by PEPTIDE bonds to form PROTEINS

44. tRNA carry specific amino acids tRNA are recycled The arrangement of the amino acids determines the type of protein that is made

45. What would translation of the mRNA transcript UAACAAGGAGCAUCC produce?