5AVERY SHOWS DNA IS THE TRANSFORMING FACTOR Oswald Avery, Alfred Hershey, and Martha Chase took Griffith’s experiment one step furtherDid experiments with virusesConcluded that DNA is the genetic material of the cell
6VIRUS EXPERIMENTS PROVIDE MORE EVIDENCE A virus consists of a package of nucleic acid in a protein coatBacteriophage- a virus that infect bacteria
27REPLICATION OF THE DOUBLE HELIX DNA Polymerase- makes the covalent bonds between the nucleotides
28Class Work1. Describe how DNA replicates by using a template. 2. List the steps involved in DNA replication. 3. Under what circumstances is DNA replicated?
29Class Work1. What are the three parts of a nucleotide? Which parts make up the backbone of a DNA strand? 2. List the two base pairs found in DNA. 3. If six bases on one strand of a DNA double helix are AGTCGG, what are the six bases on the complementary section of the other strand of DNA?
30THE TEMPLATE MECHANISM When a cell divides a complete new set of genetic instructions is made
31THE TEMPLATE MECHANISM DNA Replication- the process of copying the DNA molecule
32REPLICATION OF THE DOUBLE HELIX DNA Polymerase- makes the covalent bonds between the nucleotides
34Class Work1. Describe how DNA replicates by using a template. 2. List the steps involved in DNA replication. 3. Under what circumstances is DNA replicated?
35A GENE PROVIDES THE INFORMATION FOR MAKING A SPECIFIC PROTEIN CHAPTER 11.4 and 11.5A GENE PROVIDES THE INFORMATION FOR MAKING A SPECIFIC PROTEIN
36ONE GENE, ONE POLYPEPTIDE- Don’t need to write George Beadle and Edward Tatum worked with the bread mold neurospora crassa
37ONE GENE, ONE POLYPEPTIDE- Don’t need to write One Gene-One Enzyme Hypothesis- the function of an individual gene is to dictate the production of a specific enzymeNow…ONE GENE-ONE POLYPEPTIDE HYPOTHESIS
38INFORMATION FLOW: DNA TO RNA TO PROTEIN RNA- ribonucleic acid, has a sugar or ribose, base uracil, single stranded
39INFORMATION FLOW: DNA TO RNA TO PROTEIN DeoxyriboseThymineDouble-StrandedRNARiboseUracilSingle Stranded
41INFORMATION FLOW: DNA TO RNA TO PROTEIN Transcription- when DNA is converted into single stranded mRNA, in nucleusmRNA moves to cytoplasm while DNA stays in the nucleus
42INFORMATION FLOW: DNA TO RNA TO PROTEIN Translation- the nucleic acid information (RNA) is converted into amino acids, in cytoplasmCodon- a three-base “word” that codes for one amino acidSeveral codons form a polypeptide
43TRANSLATION: RNA TO PROTEIN Transfer RNA- translates the 3 letter codon of mRNA into an amino acid
44TRANSLATION: RNA TO PROTEIN Anticodon- a triplet of bases that is complementary to a specific mRNA sequence
49CHANGE THE DNA to mRNA 1. TAT CAT GAT 2. CCA GGG CTA 3. TAC TAG TTC 4. GCA ATA TTC5. GCA ATG CCTPAGE 12 CLASSWORK/HW
50CLASS WORK1. How did Beadle and Tatum's research result in the "one gene–one polypeptide" hypothesis? 2. Which molecule completes the flow of information from DNA to protein? 3. Which amino acid is coded for by the RNA sequence CUA? 4. List two ways RNA is different from DNA.
51THERE ARE TWO MAIN STEPS FROM GENE TO PROTEIN CHAPTER 11.5THERE ARE TWO MAIN STEPS FROM GENE TO PROTEIN
52TRANSCRIPTION: DNA TO RNA 3 types of RNAMessenger RNA (mRNA)Transfer RNA (tRNA)Ribosomal RNA (rRNA)Messenger RNA- an RNA molecule which is transcribed (COPIED) from a DNA templateRNA Polymerase- links the RNA nucleotides together
54EDITING THE RNA MESSAGE Intron- non-coding regions of DNAExon- parts of a gene that will be translated or expressedRNA Splicing- when the introns are removed from the RNA before it moves to the cytoplasm
60CLASS WORK1. What kind of nucleic acid is made during transcription? 2. How do introns and exons relate to RNA splicing? 3. List the three RNA types involved in transcription and translation, and describe the role of each. 4. Briefly describe the steps of protein synthesis.
61MUTATIONS CAN CHANGE THE MEANING OF GENES CHAPTER 11.6MUTATIONS CAN CHANGE THE MEANING OF GENES
62HOW MUTATIONS AFFECT GENES Mutation- any change in the nucleotide sequence of DNATwo typesBase SubstitutionBase Insertion/Deletion
74CLASS WORK1. Explain why a base substitution is often less harmful than a base deletion or insertion. 2. Describe how a mutation could be helpful rather than harmful. 3. Give an example of a mutagen.PAGE 13 in Packet