Midterm 1 BIO 210 Notes PDF

Domain Characteristics Cell Size Examples & Size Organisms Structure Bacteria *Belong to *single-celled 1µm - 10µm Rickettsias 1µm (in some) *cell...

Domain Characteristics Cell Size Examples & Size Organisms Structure Bacteria *Belong to *single-celled 1µm - 10µm Rickettsias 1µm (in some) *cell prokaryotes organisms ~1.0 µm Cocci 2µm *S layer (cytoplasmic) *no membrane Rods 5µm *fimbriae membrane bound nucleus Spirochete 10µm *outer membrane *chromosome or *nucleoid *cell wall nucleoid *no organelles *cytoskeleton *ribosomes *rigid cell wall *pilus *cytoplasm *capsule *inclusion/granule *microcompartments *plasmid *flagellum *endospore *intracellular membranes Archaea *(not all) live in extreme conditions Eukarya *Larger than prokaryotes *Algae *Cell membrane *Membrane bound nucleus *Fungi *Nucleus *Internal organelles (yeast, *Ribosomes molds) *Flagellum *Protozoa *Mitochondria (amoeba, *Cell wall (plants) paramecium) *Plants *Animals Other Viruses 10nm - 200nm Poliovirus 10nm HIV 70nm Herpesvirus 100nm Poxvirus 200nm Bacteria - Bacterial flagella: protein appendages that provide motility - Chemotaxis: movement towards/away from nutrients (tumble, run, tumble) - Flagellar arrangements o Polar: single flagella at one end or both ends o Lophotrichous: multiple flagella at one end from the same point on the cell o Monotrichous: one flagellum attached at one end of the cell o Amphitrichous: polar at both ends of cell  o Peritrichous: flagella all over cell § Could be E. Coli - Periplasmic flagella o Move by sliding past each other - Spirochete: any of a group of spiral-shaped (corkscrew) bacteria o Ex. Borrelia burgdorferi § Lyme disease - Fimbriae: rod-like proteinaceous appendages o Shorter than flagella o Adherence - Conjugation pili: long proteinaceous, tubular appendages o Control transfer of DNA during conjugation - Capsules/slime layers o Made of polysaccharide o Adherence o Other: § Colonies w/ capsules – wet, mucoid, slimy, sticky § Colonies w/o capsules – dry, dull - Axial filaments: long, coiled threads that provide movement to spirochetes Biofilm formation - Adhere microbial communities together (bacteria, fungi, algae) - Good vs. Bad o Good: E. Coli o Bad: Staphylococcus § Drug resistance § IV in arm – bacteria travels through bloodstream o Bad: Salmonella § Food poisoning - Planktonic (free moving) cells do not always need flagella - Mixed cultures – not viruses Cell wall - Shape and structural support - Composition: peptidoglycan (PG) - Distinguishes Gram-positive and Gram-negative bacteria  Components Gram-positive *Peptidoglycan (thicker in +) Gram-negative *Cell membrane *Periplasmic space *Outer membrane (extra layer) *LPS Peptidoglycan (PG) Structure - Alternating series of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) - Joined NAG and NAM form glycan chain held together by tetrapeptide chain - ** Lysozyme: enzyme that prevents synthesis o Ex. eye – washes every blink o Ex. mouth, saliva, tears Comparison of Gram-Positive and Gram-Negative Cell Walls Characteristic Gram-Positive Gram-Negative # of layers 1 2 *Peptidoglycan Chemical *Periplasmic space: transport in/out cell composition *Cell membrane & phospholipids: hydrophilic head, hydrophobic tail *Membrane proteins: transport in/out cell *Teichoic acid: provides (-) charge to cell surface *Lipopolysaccharide (LPS): toxic to humans; bloodstream infection; released when dies *Lipoteichoic acid: provides (-) charge to cell surface *Lipoprotein: transport in/out cell; PG synthesis *Mycolic acids and polysaccharides (some cells) *Porin proteins: transport in/out cell *Outer membrane layer Overall Thicker (20-80nm) Thinner (8-11nm) thickness Outer No Yes membrane Example E. Coli Bacteria lacking a cell wall: - Mycoplasma spp. - Mycoplasma pneumoniae o Pneumonia – survives in osmotic environments - Result – susceptible to lysis Bacterial Endospores - Characteristics: o Resistant to heat, desiccation (dehydration), chemicals, UV light o Thick and strong layers – not reproductive – survival structures o Bacteria sense starvation and begin sporulation o Only found in the environment and are not medically relevant o Can remain metabolically inactive (dormant) § DNA bacteria inside § No respiration, no growing - Bacterial genera examples: o Clostridium § Neurotoxins § Only lives in absence of oxygen o Bacillus § Antibiotics § Lives w/ or w/o oxygen - Formation process: 1. Vegetative cell Actively growing w/ 1 chromosome 2. Chromosome is duplicated and separated 3. Cell is separated into a sporangium and forespore Sporangium helps synthesize forespore 4. Sporangium begins to actively synthesize spore layers around forespore a. Cortex forms and provides for desiccation and UV radiation 5. DNA breaks down in the sporangium (DNA still intact in endospore) 6. The free spore is released when the dead sporangium falls away 7. During germination, the spore swells and releases a vegetative cell a. Nutrient rich conditions  Cell Morphology Name General Shape/Characteristics Organism Example Coccus (pl. cocci) Round, circle Staphylococcus aureus Rod/Bacillus (pl. rods/bacilli) Bar, rod Legionella pneumophila Vibrio (pl. vibrios) Curved bar Vibrio cholerae Other Spirillum Spiral, Rigid, polar flagella; thicker, corkscrew Aquaspirillum Spirochete Spiral, Flexible, periplasmic flagella; thinner Borrelia burgdorferi (Lyme Disease) Branching filaments Bacteria Streptomyces species Cell arrangement - Palisades o Next to each other o Attached end to end fold back on each other to form rows of side-by-side cells - Pleomorphism o Different shapes - Ex. Corynebacterium diphtheriae Cell Division and Arrangement Division in one plane 1 cell Þ Diplococci – 2 cells Þ Streptococci – variable number of cocci in chains Division in two perpendicular planes 1 cell Þ Tetrad – cocci in packets of four Þ Sarcina – packet of 8-64 cells Division in several planes 1 cell Þ Staphylococci & Micrococci: Irregular clusters – number of cells varies Streptobacilli: Rod-shaped bacteria divide multiple times on their transverse planes and do not separate therefore the cells continue to be attached to each other Diplobacilli: Two rod-shaped bacteria divide on the transverse plane and do not separate Comparisons of Domains Eukarya Eukaryotic Cells 70S ribosomes Cell walls in some Similar protein synthesis as Archaea Bacteria Prokaryotic Cells (Archaea similar to Eukarya) Peptidoglycan in cell wall Archaea 80S ribosomes Pseudopeptidoglycan, polysaccharides or glycoprotein Similar protein synthesis as Eukarya S-layers in cell wall Methanogens - Found in anaerobic regions (sediments in lakes, oceans, intestinal tract and oral activity) - Convert CO2 and H2 into CH4 (methane) - Contribute to global warming Extreme halophils - Require high concentrations of salt to grow - Tolerance as high as 36% NaCl Refraction: bending or change in the angle of light as it passes through a medium - Use oil with 100X oil immersion lens - Oil has some optical qualities as glass – prevents refractive loss – increases numerical aperture Resolving power: ability to show detail Resolution: capacity to distinguish or separate two adjacent objects - Shorter visible wavelengths = better resolution - Blue filters limit longer wavelengths Microscopes Light or Optical Maximum Characteristics/Other resolution With visible light illumination 0.2µm Anything bigger you can see, anything smaller no With UV or laser beam illumination 0.2µm Useful magnification: 2,000x Maximum resolution: 200nm (0.2µm) Using a beam of electrons Transmission electron microscope (TEM) 0.5nm Electron (transmission) Scanning electron microscope (SEM) 10nm Useful magnification: 1,000,000x or more Maximum resolution: 0.5nm Comparisons of Types of Microscopies Comparative Images from Optical Microscopes Name Description Other Bright-field microscope Specimen is dark, field is white Use all live specimens Dark-field microscope Specimen is bright, field is dark Phase-contrast microscope Specimen is contrasted against gray background Differential interference contrast Provides very detailed, highly contrasting, 3D images of live microscope specimens  Modifications of Optical Microscopes with Specialized Functions Fluorescent microscope Antibodies labeled with fluorescent dyes emit visible light only if Stain DNA; used for diagnostics; stains the the antibody recognizes and binds to the cell cell surface Confocal microscope Cells are stained by fluorescent dyes, and scanned by a laser Stain, laser, computer beam, form multiple images that are combined into a 3D image Electron Microscopes Image Objects with a Beam of Electrons (**need these to see viruses) Transmission electron microscope Heavy metal stains are used to stain the specimen. The electron Non-living specimens (ex. Influenza virus (negative staining) (TEM) beam detects the stain and diffracts (bounces back) particle) Thin section (-) stain: stain thin, cut layers; see inside cell Colorized transmission electron Colorized version of the same TEM image microscope image Scanning electron microscope Specimen is covered in a layer of gold and scanned across the Artificially colorized SEM image of (SEM) surface Middle East respiratory syndrome Coronavirus viral particles (yellow) on the surface of a eukaryotic cell (blue) Colony: formed from a single cell that replicates many times Agar plate: agar is a solid medium required for growth of the colony; comes from red algae; not a nutrient – just a place to live; viruses cannot live on them Streak plate: goal is to obtain isolated colonies and eventually select one to use and grow as a pure culture - Use fire to sterilize loop Methods of plating agar 1. Streak plate method a. Sterile loop containing sample b. All cells grow on top of agar 2. Pour plate or serial dilution method a. Use agar in sterile/melted form b. Colonies grow on surface and in the agar 3. Spread plate method a. Use a ‘hockey stick’ to spread on top of agar Pure culture: colonies all look the same (color, texture, shape) Pouring an agar plate - Solid nutrient gelatin medium  - Liquid gelatin and microbial enzymes digest (used for diagnostic labs) Defined (synthetic) medium: exact chemical composition is known, and each batch is chemically identical Complex medium: composition that is chemically different each batch - Extracts are common to be part of complex mediums Examples of Selective Media, Agents, and Functions Medium Selective Agent Used For Mannitol salt agar (MSA) 7.5% NaCl Isolation of Staphylococcus aureus MacConkey agar (MAC) Bile, crystal violet Isolation of gram-negative enteric (in gut; E. coli) Eosin-methylene blue agar (EMB) Bile, dyes Isolation of coliform bacteria (in intestinal tract) Blood agar: used as a differential medium - Blood has nutrients that support growth - Ex. RBC from sheep - Alpha hemolysis: less well-defined zones around the colonies - Beta hemolysis: well defined zones around the colonies (complete RBC breakdown; see light around colonies through plate) - Gamma hemolysis: no hemolysis Examples of Differential Media Medium Substances that facilitate differentiation Differentiates Blood agar RBC Hemolysis types Mannitol salt agar (MSA) Mannitol (sugar alcohol), phenol red (pH indicator) Species of Staphylococcus *ferments alcohol, creates acid, pH decreases, pH indicator changes color *red to yellow medium indicates fermentation MacConkey Agar Lactose (sugar), neutral red (pH indicator) Bacteria that ferment lactose (lowering pH) from Eosin-methylene blue Lactose, eosin, methylene blue those that do not Triple-sugar iron agar Triple sugars, iron, and phenol red Fermentation of sugars, H2S production *contains dyes and bile to inhibit gram-positive bacteria MacConkey agar - Selective medium o Bile salts inhibit most Gram-positives and allow most Gram-negatives to grow o Crystal violet dye inhibits most Gram-positives and allows most Gram-negatives to grow - Differential medium o Lactose: fermentation produces acid o Neutral red indicator: pink/red/purple = fermentation; white/cream = no fermentation Triple sugar iron agar - 3 sugars: lactose, sucrose, glucose (fermentation leads to acid production) - Phenol red pH indicator: yellow = acid production; red = basic medium - Iron salt ferrous sulfate: shows H2S gas production Comparison of Positive and Negative Stains Positive Staining Negative Staining Appearance of Cell Colored by dye Clear and odorless Cell surface is (-) Cell surface is (+) Stain is (+) Stain is (-) Cells stained; background not stained Cells not stained; background stained Simple and Negative Stains - Use 1 dye to observe cells - Crystal violet stain of Staphylococcus aureus o Coccus morphology o Grape-like cluster arrangement - *Bacillus and Staphylococcus made with nigrosin o Nigrosin colors the background black Differential Stains - Use 2 dyes to distinguish between cell types - Acid-fast stain o Red cells – acid-fast o Blue cells – non-acid-fast - Endospore stain o Spores – green o Vegetative cells - red The Gram Stain Procedure: helps differentiate gram-positive & negative based on cell wall thickness Microscopic appearance of cell Chemical reaction in cell Steps Gram (+) Gram (-) Gram (+) Gram (-) 1. Crystal violet (primary dye) Purple Purple Both cell walls stain w/ the dye 1a. Wash w/ distilled water 2. Gram’s iodine (mordant) Purple Purple Dye crystals trapped No effect Function: traps crystal violet in thick PG in cell 2a. Wash w/ distilled water 3. Alcohol (decolorizer) Purple White Crystals remain in cell Outer wall is weakened; Function: washes out crystal violet of gram (-) b/c PG is thin cell loses dye 3a. Wash out 4. Safranin (red/pink dye counterstain) Purple Red/Pink No effect Stains the colorless cell Function: stain gram(-) cell Ziehl-Neelsen acid-fast stain: used for presumptive identification in diagnosis of clinical specimens - Mycobacterium tuberculosis causes TB o Acid-fast bacterium o Red cells after stain - Primary dye o Carbol fuchsin (red dye) + heat 5 minutes (mordant) § Colors acid-fast bacteria red - Decolorizer o Generally acid alcohol § Removes stains from the non-acid-fast bacteria - Counter stain o Methylene blue § Non-acid-fast bacteria – blue § Acid-fast bacteria – red - Mycolic acids (in place of PG) as part of cell wall o Waxy – cells don’t stain well w/ gram stain - *All cells whether acid-fast or not stain grey Schaeffer-Fulton endospore stain (spore stain) 1. Malachite green (primary stain) is forced by heat (mordant, drives it into cell) into cells and into resistant bodies (endospores) 2. Rinsing w/ water washes out malachite green from cells – leaves stain in endospores 3. Counterstain with safranin - Vegetative cells – pink/red o Actively dividing/metabolizing - Endospores – green o Latent/dormant Flagella stain: staining increases the diameter of the flagella and increases visibility of flagella - Can’t see flagella w/o stain – too thin - Structural stain / simple stain - Ex. Bacillus cereus o See movement and structure Autotroph: use inorganic source of carbon (carbon dioxide) Heterotroph: catabolize reduced organic molecules as source of carbon Chemotroph: acquire energy from redox reactions using inorganic and organic compounds Phototroph: use light (photosynthesis) as energy source Nutritional Categories of Microbes by Energy and Carbon Source Microbe Source of carbon uses Source of energy it uses Photoautotroph CO2 Sunlight Photoheterotroph Organic carbon Chemoautotroph CO2 Simple inorganic chemical compounds Chemoheterotroph Organic carbon Organic chemical compounds ‘Obligate:’ requirement of condition for growth - Ex. Clostridium spp. (obligate anaerobes) ‘Facultative:’ not so restrictive; adapts to wider range of conditions - Ex. A facultative anaerobe (can grow w/ or w/o O2) Optimum temperature for growth - Too high = denatures proteins; cell membranes become too fluid - Too low = rigid and fragile membranes - Chart o Psychrophile: -20 to 15 § Artic and Antarctic o Psychrotroph: 5 to 35 o Mesophile: 10 to 50 § Most things that grow in the human body § Ex. E. coli at 37 o Thermophile: 45 to 80 § Hot springs o Extreme thermophile: 65 to 130 § Hydrothermal vents; usually archaea Environmental factors that influence microbes – oxygen - Oxygen can transform into toxic products: o Singlet oxygen (1O2), superoxide ion (O2-), peroxides (H2O2), and hydroxyls (OH-) can destroy cells o Most cells have enzymes (ex. Superoxide dismutase, catalase) to capture and neutralize these toxic products § *Aerobic, facultative anaerobic organisms have these, but anaerobic organisms do not Oxygen requirements - Aerobes: undergo aerobic respiration - Microaerophiles: aerobes that require oxygen levels from 1-15% - Facultative anaerobes: do not need oxygen and can grow w/o it - Obligate anaerobes: cannot tolerate oxygen (toxic) - Capnophiles: grow optimally at carbon dioxide levels of 3-10% - Aerotolerant anaerobes: can survive and grow in oxygen Thioglycolate broth: a reducing medium; the oxygen concentration decreases with depth in the tube (obligate anaerobe at bottom of tube) Glovebox: an anaerobic chamber for cultivation of anaerobes Anaerobic culture system: made of an air evacuation system and gas generator packet pH - Neutrophiles: grow best in narrow range around neutral (6.5-7.5) - Acidophiles: grow best in acidic habitats (7.5) All microorganisms require water for growth – allows chemical reactions to run and hydrates - Osmophiles: live in habitats with a high solute concentration (hypertonic) - Facultative halophiles: can tolerate high salt environments o *Ex. Staphylococcus aureus in nasal passages or on skin - Obligate halophiles: bacteria that must have high salt for cell growth (up to 30% salt) o *Ex. Halobacterium (member of Domain Archaea) Physical effects of water - Exerts pressure in proportion to its depth - Barophiles (air and water pressure): organisms that live under extreme pressure (ex. at bottom of ocean) Principles of bacterial growth - Divide by binary fission (1 cell splits to 2) – not mitosis or meiosis - Doubling time/generation time: time required for parent cell to divide and produce 2 daughter cells o *exponential growth: Initial # cells x 2n = # cells after growth § n = doubling time or generations Bacterial growth curve 1. lag phase: growth lags; cells adjusting; not multiplying at max. rate 2. log phase: exponential growth, max rate of cell division 3. stationary phase: cells stop growing/grow slowly; metabolic rate declines; see depletion of nutrients, buildup of wastes 4. death phase: cells die off - Drawing – x-axis (time), y-axis (logarithm of viable cells) Measuring microbial growth - Viable plate count o Measures viable cells growing on solid culture media o Count based on assumption that one cell gives rise to one colony § Number of colonies = number of cells in sample § Ideal number to count is 30-300 colonies  - Turbidity method o Measures with spectrophotometer § Measures light transmitted through sample Measurement is inversely proportional to cell concentration § Limitations: must have high number of cells; cannot differentiate between living and dead cells § *cells sink to bottom - Direct cell count o Bacterial cell number is measured in a known volume in a hemocytometer o *Does not distinguish between living and dead cells Pathogen: a microbe that can cause harm (fungus, virus, bacteria) Procedures for identifying pathogens and diagnosing infections - Phenotypic: physical traits o Ex. biochemical tests, motility - Macroscopic examination: see w/ naked eye o Color/Height of culture and colony o Texture – smooth, rough, wet, dry - Microscopic examination: see w/ microscope o Morphology and arrangement o Endospores present? o Differentiate gram-negative or gram-positive o Microbacteria w/ acid-fast stain - Physiology, biochemistry o Fermentation o Enzymes present? o Aerobes vs. anaerobes o Catalase test - Genetic analysis o Obtain DNA sequence and use known pathogen data base to compare o PCR: copies of DNA of particular sequence - Immunologic examination o Using antibodies that attach to antigens o Use a fluorescence microscope § Antibodies attach to cell surface Diagnosing pathogens 1. Sample patient site with a sterile swab and put in broth 2. Aseptic techniques (PCR test) 3. Handling and transport to the lab a. Mixed culture sent – what’s normal on skin? Virulence factor: property of a pathogen (organism) that helps it cause infection and disease - Examples: toxin made by bacteria, flagella that help cell movement through host, pili stick to surface, LPS Diagram of skin - Ex. cut on skin through which pathogen enters - On surface of skin: yeast and bacteria - Skin defense: showering sheds a layer of skin - Sweat (oil) glands: contain compounds that are antimicrobial o Salty skin is an adverse environment for some (*Staphylococcus aureus) Staphylococcus aureus - Causes: skin infections, food intoxication (toxemia due to presence of toxins), pneumonia, and bacteremia (blood stream infection) - Resists high salt concentration (7.5-10%) – facultative halophile - Morphology/Arrangement: coccus; grape-like clusters - Identification w/ beta-hemolysis using RBC (completely lyse caused by a-toxin - Biofilm former: found on aesthetic devices Major Virulence Factors of Staphylococcus aureus Name Enzyme/Toxin Effect Coagulase *diagnosed by this Enzyme Coagulated blood plasma (forms clot around *Staphylococcus epidermitis doesn’t normally bacterial cells; protects immune system) make this Hyaluronidase *part of connective tissue that Enzyme Digests connective tissue of host breaks it down – goes deeper into tissue – allows bacteria to spread Hemolysins (a, b, g, d) Toxin Lyse RBCs Enterotoxins *active against gut Toxin Induce nausea, vomiting, diarrhea (food poisoning) Exfoliative toxins (A, B) Toxin Cause desquamation of skin Toxic shock syndrome toxin (ex. tampons) Toxin Induces fever, vomiting, rash, organ damage, fatal Local staph infections - Abscess: Inflamed fibrous lesion enclosing pus Systemic staph infections - Spread to specific sites from local cutaneous infections o Bones (osteomyelitis), organs (pneumonia), bacteremia (blood stream) Staphylococcal Scalded Skin Syndrome (SSSS) - Some S. aureus strains - Exfoliative toxins - Rarely fatal, but possible w/ secondary infections - Prevention is challenge due to transmission between people o Use PPE and wash hands o Treat w/ antibiotics o Elderly and young more susceptible – prime immune system age (20) Tests used to differentiate Staphylococcus (clusters) from Streptococcus (linear chain, oral cavity) - Catalase test: add H2O2 to bacterial growth; positive test shows production of bubbles (release of oxygen) - Coagulase test: tube of plasma inoculated w/ organism; positive test shows clot formation (coagulase produced) o Epidermis is negative - Antibody-latex bead agglutination test: positive test shows clumping (antibody binds to Staphylococcus) Metabolism - Anabolism: building up molecules from smaller units (monomers); requires ATP; endergonic reactions - Catabolism: breaking down large molecules; releases ATP; generates reducing power Redox reaction - LEO: loses electron; oxidized - GER: gains electron; reduced o Energy is carried by electron - FADH2 and NADH have reducing power - 𝑁𝐴𝐷! (𝑜𝑥𝑖𝑑𝑖𝑧𝑒𝑑) + 𝐻 ⇌ 𝑁𝐴𝐷𝐻 (𝑟𝑒𝑑𝑢𝑐𝑒𝑑 𝑓𝑜𝑟𝑚) o NAD+ and NADH are electron carriers - 𝑋 → 𝑋𝐻 - 𝐹𝐴𝐷(𝑜𝑥𝑖𝑑𝑖𝑧𝑒𝑑 𝑓𝑜𝑟𝑚) + 2𝐻 ⇋ 𝐹𝐴𝐷𝐻" (𝑟𝑒𝑑𝑢𝑐𝑒𝑑 𝑓𝑜𝑟𝑚) Electron Transport Chain (ETC): in cytoplasmic membrane; series of redox reactions Respiration: high concentration of oxygen to low concentration - Complete aerobic respiration: 6𝑂" + 𝐶# 𝐻$" 𝑂# → 6𝐶𝑂" + 6𝐻" 𝑂 + 𝐴𝑇𝑃 - Facultative anaerobe ex. E. coli Glycolysis: partial breakdown of glucose - All cells do this; easily accessible - 1 𝑔𝑙𝑢𝑐𝑜𝑠𝑒 (6𝐶) C⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯E 2 𝑝𝑦𝑟𝑢𝑣𝑎𝑡𝑒𝑠 (3𝐶) + 2𝑁𝐴𝐷𝐻 + 2𝐴𝑇𝑃 (𝑛𝑒𝑡 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠) %&'()% +,-.%& /0%1/ o 1 step involves substrate level phosphorylation (SLP) § Donation of a phosphate from an organic compound to another Oxidative Phosphorylation - Uses loss of electron to generate ATP - Uses both the ETC and chemiosmosis together o Movement of chemical from high to low concentration across a membrane Proton Motive Force: proton gradient using ATP synthase (enzyme) to generate ATP Glycolysis: partial oxidation of glucose - Overall a catabolic reaction - Most ATP comes from ETC and chemiosmosis – not Krebs cycle - SLP in glycolysis and Krebs cycle Prokaryotic Aerobic Respiration Glycolysis Transition Krebs Input 1 glucose 2 pyruvate 2 Acetyl Co-A *one at a time Output 2 pyruvate 2 Acetyl Co-A 3 NADH x 2 ( = 6 NADH) 2 NADH CO2 1 FADH x 2 ( = 2 FADH) *2ATP (net) 2NADH CO2 1 ATP x 2 ( = 2 ATP) Total 8 ATP 6 ATP 24 ATP Net 38 ATP total Fermentation: done by microbes that cannot respire - Examples: o Eukaryotes: Saccharomyces cerevisiae (yeast) o Prokaryotes: many species of bacteria; some produce acids (ex. Lactobacillus); some produce ethanol - *Involves glycolysis – cannot occur w/o it - All in cell cytoplasm