MIC 230 1st Edition Lecture 13 Outline of Last Lecture I. Advantages/disadvantages of bacterial genetics II. Significant discoveriesIII. Concepts/definitionsIV. Structure of DNA/RNAa. Central DogmaOutline of Current Lecture V. DNA replicationVI. Transcription VII. Translationa. RegulationCurrent LectureVI. DNA replication-Semiconservative-Origin siteorigin of replication starting point-Requires: template: DNA (1 strand)Building blocks: deoxyribonucleotides (dNTPs)EnzymesDNA polymerase: adds dNTPs to 3’ OH-Helicaseunwinds DNA-DNA ligaseattaches 3’ OH 5’ PO4 to close “holes” in DNA1 piece of DNAVII.Transcription (synthesis of RNA)Template: DNA (1 strand)Building blocks: ribonucleotides (NTPs)Enzyme=RNA polymerase4 subunits3 form core polymerasemakes RNASigma subunitrecognizes a promoter (determines what gets transcribed/expressed)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.-Many different subunits (sigma factors)Prokaryotes often have operons-Set of genes under control of 1 promoterVIII. Translation Template: mRNA contain the codon information because in sets of 3 have a reading frame start at right point for sets of 3 to be correctWorkers: tRNA-Ribosomal RNA transfers amino acids from cytoplasm to ribosome, has anticodon- binds to codon and has an amino acid attached that matches codon-Ribosome (factory)Process: 1. Initiation -Assembly of 2 subunits of the ribosome -Initiator tRNA -Initiation factors -All around the mRNA -Ribosome binding site 2. Elongation Ribosomes have 3 sitesA siteacceptor site where tRNA entersP site peptide site w/growing a.a. chain-A and P have peptide bonds form between 2 a.a. in those sites E site exit site where tRNA leaves 3. Termination releasecomes to stop codon release polypeptide 4. Polypeptide processing needs to fold properly-Some spontaneously fold on own-Some needs chaperone proteins (chaperonins) to assist in folding so are active-Some need to be transported to specific area first then processedIX. Regulation occurs at 3 different levels1. Level of activityproteins are made but can be turned on and off2. Level of translationmRNA is made but not the protein3. Level of transcriptionis the DNA transcribed or not sigma factorsdetermine what is transcribed I. Bacterial genetic variability due to a. Mutationb. Gene exchange II. Mutationsa. Definitions:1. Mutationchange in base or bases in the DNA sequenceChange in genotype2. Mutants an organism w a mutation3. Wild type original organism without the mutation 4. Mutagensan agent that causes a
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