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Chapter 11 DNA and the Language of Life (protein synthesis) 11.1 11.2 11.3 11.4 11.5 11.6 Genes are made of DNA honors Nucleic Acid Sequence (A,T,G,C) DNA replication = inheritance 1 Gene 1 Protein Steps from Gene to Protein Mutations in genes 1 11.1 Genes are made of DNA Mendel didn’t know about DNA Griffith-1928-transforming factor 2 Bacteria The harmful dead changed the harmless living into harmful living Some “transforming factor” remained active 2 11.1 Genes are made of DNA ► Avery-1944- Transforming factor was DNA not protein Scientists were skeptical because protein was very prevalent ► Hershey and Chase- Radioactive Virus Experiments DNA is The genetic material 3 11.2 Nucleic Acid Sequence (A,T,G,C) Nucleotides (A,T,G,C) are monomers (units) of nucleic acids 3 parts: (sugar) deoxyribose(DNA) or ribose (RNA) Phosphate group Nitrogenous bases pyramidines purines 4 11.2 Nucleic Acid Sequence (A,T,G,C) Nitrogenous bases pyrimidines Single ring (Cytosine, Thymine, U) purines Double Ring (Guanine,A) 5 11.2 Nucleic Acid Sequence (A,T,G,C) 1950’s Franklin and Wilkins- DNA helix Watson and Crick-Double helix Base pairings C-G (Pyrimidine +Purine) fix notes A-T (Pyrimidine +Purine) 6 11.3 DNA replication = inheritance Figure 11-9 During DNA replication, the two strands of the original parent DNA molecule, shown in blue, each serve as a template for making a new strand, shown in yellow. Replication results in two daughter DNA molecules, each consisting of one original strand and one new strand. 7 11.3 DNA replication = inheritance Figure 11-10 DNA replication both directions "bubbles." bubbles merge two daughter DNA 8 11.4 1 Gene 1 Protein The bases: A,T,G,C are the letters in the language of Life The letters make up genes Sentences are the polypeptides (proteins) 9 11.4 1 Gene 1 Protein Several RNA molecules play a part in the intermediate steps from gene to protein 10 11.4 1 Gene 1 Protein Each codon stands for an amino acid. (The table uses abbreviations for the amino acids, such as Ser for serine.) The codon AUG not only stands for methionine (Met), but also for "start“. There are also three "stop" codons that do not code for amino acids, but signal the end of each genetic message. 11 11.5 Steps from Gene to Protein Transcription: DNA to RNA http://www.dnai.org/a/index.html 12 Go to interactive screen- reading the code- putting it together -interactive 3 types of RNA mRNA-messenger tRNA-transfer rRNA-ribosomal 13 RNA splicing Introns stay IN nucleus Exons EXit nucleus mRNA doesn’t Contain introns 14 11.5 Steps from Gene to Protein Translation: RNA to Protein Figure 11-19 1.Translation begins with the attachment of a ribosome and the first tRNA to a "start" (AUG) codon. 2. The ribosome then moves along the mRNA. The polypeptide elongates as an amino acid is added for each codon. 3. When the ribosome arrives at a "stop" codon, the completed polypeptide is released 15 16 17 18 19 20 21 22 23 24 25 26