MIC 205 1st Edition Lecture 12 Outline of Last LectureI. Physical Methods of Microbial ControlII. Chemical Methods of Microbial ControlOutline of Current Lecture III. Controling Microbial Growth Cont.a. Biofilms IV. Microbial GeneticsCurrent Lecture Biofilms- Complex bacterial communities that exist as an organized film of microbeso Difficult to get rid of (tough, strong)o Resistance properties that individual cells do noto Multilayered, cells in different metabolic stateso Different species of bacteria 1. Examples: contacts, teeth, pebbles in a stream, medical cathetersBiofilm Formation- 5 steps 1. Surface attachment2. Produces thick, protective ECM3. Microcolony formation and signaling4. Formation of complex biofilm with chemical gradients that recruit other species of microbes5. Detach and dispersal of microbes- Signaling in 3rd and 4th steps occurs through acylated homoserine lactonesMicrobial DNA- Genome = entire genetic complement of an organism (nucleotide sequence and genes)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.Replicationo Exact duplication of entire DNA genome for reproductiono Transcription: DNA into RNA sequenceso Translation: Synthesis of protein through interpreting the RNA sequenceNucleotide Structure- Monomers of nucleic acids- 3 parts1. Phosphate group2. Pentose sugar (Deoxyribose-DNA, Ribose-RNA)3. Nitrogenous base (A,G,C,T, U)- Read from 5’ to 3’ endProkaryotic Genomes- Contained in chromosomes and plasmidso Chromosomes: main portion of DNA (“engine, steering wheel, tires”)- 1-2 per cell- Nucleoid (circular molecules of DNA in cytoplasm)- NO histones o Plasmids: small, circular molecules of DNA that replicate independently (“add bling”)- Multiple copies- Carry info for own replication (supplementary-not necessary)- Ex) nutritional, reproductive, antibiotic resistanceEukaryotic Genomes- Nuclear chromosomes and extranuclear DNAo Nuclear chromosomes Linear (not circular) Multiple within the nucleus More than one chromosome per cell Long molecules o Extranuclear DNA DNA of mitochondria and chloroplasts are circular (resembles chromosomes of prokaryotes)- Some fungi and protozoa have plasmids in
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