MIC 205 1st EditionExam # 2 Study Guide Lectures: 8 – 14 Lecture 8- Aerobic Respiration1. Pyruvate oxidation- 2 step process-extracts energy to produce a molecule of NADH- Emits CO2- Left with Acetyl group that attaches to CoA (co-enzyme)2. Krebs (Citric Acid) Cycle- Starts with the Acetyl-CoA- makes a lot of NADH (energy extraction)- CO2 released3. Electron Transport Chain- Energy from prior steps is pumped into the ETCi. Electrons from NADH go into the electron carriersii. These energized electrons go to a lower energy state and protons are pumped out of cell (creates electro-chemical gradient) (Hydrogen ions on outside and electrons inside)iii. Electrons form water when combined with oxygeniv. As protons come back into the cell through ATP synthase—ADP is converted into ATPv. ATP synthase only works if there is a gradientvi. Oxidative phosphorylation—proton gradient created by oxidation of components of ETC**Produces more ATP than other pathwaysTotal ATP = 38 molecules- Anaerobic Respirationo No oxygen needed- Fermentationo Not a respiration process Involves glycolysis- Provides cells with alternate sources of NAD+- Main goal is to regenerate NAD+o 2 types: Lactic Acid & Alcoholic Fermentationo Only produces 2 ATP molecules-- Photosynthesis o Sunlight needed to collect energy and create photosystems- Light Independent Reactions Use ATP and NADPH to make sugar from carbon dioxide and waterLecture 9- Microbial Growtho Growth by increasing cell number Logarithmic growth: exponential growth Arithmetic growth: addition of growth at each round- Phases of Microbial Growth:o lag phase: # of cells remain constant, haven’t started dividing yeto log phase: # of cells increases exponentiallyo stationary phase: # of new cells = # of cells dyingo death phase: more cells dying than being produced, negative slope- Nutritional Requirements:o phototrophs: lighto chemotrophs: organic or inorganic chemical products- Physical Requirements:o autotrophs: carbon from CO2 (self feeder)o heterotrophs: carbon from other living organisms- Oxygen Requirements:o obligate aerobes-need oxygeno obligate anaerobes-can’t be exposed to air Oxygen Classifications:- Aerobes- Anaerobes- Facultative anaerobes- Aerotolerant anaerobes- MicroaerophilesLecture 10:- Physical Requirements for growth:o Temperatureo pHo water- Microbial control:o Sterilization- completely gets rid of all microbeso Aseptic-working in a lab/healthcare setting with the absence of microbeso Disinfection/disinfectants-removes most of the microbes (NOT all) using chemicalso Antisepsis/antiseptic-disinfection of human surfaceso Degerming-physical disinfection by scrubbing, rubbingo Sanitization- disinfection of public surfaceso Pasteurization- disinfection of foods/drinks with mild heat- Microbial Death:o Antimicrobial agents kill microbes Alter cell wall Interfere with protein/nucleic acid structureLecture 11:- Physical Methods of Microbial Controlo Exposure to heat Achieve sterility—autoclave in moist heat (applies pressure to make waterboil at higher temps) Incineration is ultimate means of sterilization (long and hot)o Pasteurization—NOT sterilization Small amounts of heat for short time Doesn’t kill heat tolerant microbes Kills some spoilage microbeso Exposure to cold Inhibits growth Lyphophilization = freeze drying, removes watero Desiccation—Remove water (dry out) Static process Builds capsule to preserve structureo Filtration Remove microbes from liquids Achieve cellular sterilityo Osmotic Pressureo Radiation Short wavelength  Achieve sterility UV = nonionizing Gamma = ionizing- Chemical Methods of Microbial Controlo Phenols: denature membrane Ex) Lysolo Alcohols: control growth, short contact time, denature membrane Ex) isopropyl, methanol, ethanolo Halogens: damage enzymes by oxidation/denature Ex) chlorine, iodine, fluorineo Oxidizing agents: oxidize microbial enzymes and membrane lipids Ex) hydrogen peroxide, ozoneo Surfactants: reduce surface tension, solubilize lipids Ex) soap, detergentso Heavy metals: alter 3D protein shape Ex) lead, copper, silver, mercuryo Aldehydes: preserve material, killing agent Ex) formaldehydeo Gaseous agents: Denature proteins and DNA Ex) ethyl oxides, ether gaso Antimicrobics: target specific microbes Ex) drugsLecture 12:- Biofilms:o Complex bacterial communities that exist as an organized film of microbeso Tough, hard to get rid of Ex) contacts, pebbles in streams, teeth, medical catheters- Biofilm formation:o 5 steps1. 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- Microbial DNAo Genome = entire genetic complement of an organism (nucleotide sequence and genes)Replicationo Exact duplication of entire DNA genome for reproductiono Transcription: DNA into RNA sequenceso Translation: Synthesis of protein through interpreting the RNA sequenceNucleotide Structureo Monomers of nucleic acidso 3 parts1. Phosphate group2. Pentose sugar (Deoxyribose-DNA, Ribose-RNA)3. Nitrogenous base (A,G,C,T, U)o 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 cytoplasmLecture 13:o DNA Replicationo Three key concepts1. Replication is semiconservative- One parental one daughter strand2. Replication requires a step-wise process- Remove DNA associated proteins, helicase, synthesize RNA primers (starting blocks for synthesis), DNA polymerase III extendsthe primers, degrade RNA primers and fill in gaps with DNA polymerase I, and rewind new strands. 3. DNA polymerase III synthesizes new DNA strands in only