Lecture 5 Swimming Tumbling spin counterclockwise flagella not bound move back and forth in little space Run rotate clockwise flagella bind together more attractants more runs Spirochete twisting way through media flagella don t make it through outer membrane stay b w outer and cell membrane rotating of flagella twists entire cell Twitching extension and retraction of pili into cell pili are like arms can extend from body and bind to chemicals to pull itself in bacteria disassembles pili as it enters cell pili assembled inside cell one subunit at a time and pushed out attachment of pilus tip to surface is very specific pili and flagella cannot be seen under microscope can see movement though pili good for liquid media and attaching to surfaces walk along Pushing actin filaments being synthesized behind the cell and move around by this pushing inside the cell is great place to live b c of nutrients and environment happens inside cell Sliding have slime jets that push out polysaccharides like rocketship good motility for damp surfaces ie soil but not liquid media Prok Cytoplasmic Membrane phospholipid bilayer phosphate heads lipid tails hydrophobic interior hydrophillic exterior gases and water diffuse through large molecs trapped on one side or another permeated by proteins transport sensing embedded or span whole bilayer Bacterial cytoplasic membrane energy storage harvest light energy in photosynthetic bacteria selectively permeable naturally impermeable to most substances proteins allow substances to cross maintain concentration and electrical gradient Passive Movement 1 Simple Diffusion move down concentration gradient 2 Facilitated Diffusion molecs too big or polar to pass through proteins allow movement down concentration gradient 3 Facilitated diffusion through permease protein bind to substrate and induces change in shape of protein that allows passing no energy used high to low conc 4 osmosis water moves across at low rate through specific proteins Effects of solutions on cells animal cells w o cell wall shrink burst more easily plants and bacteria cells w cell wall not subjected to as extreme conditions can survive better in hypotonic solution because it can push out more w o bursting Active transport move chemicals UP concentration gradient 1 uniport molec inside cell recognized my transport protein use ATP to transport across CM 2 antiport transport of molec outside cell is couple by transport of molec inside cell simultaneous 3 symport transport of two molecs at same time in same direction 4 coupled transport 2 of these Lecture 6 Group Translocation ex glucose must be moved up conc gradient detects glucose molec binds them phosphorylates them substance chemically altered during transport found only in some prokaryotes Active transport ATP dependent usu with ions Na K Cl Environmental factors affecting how cells grow 1 Temperature 2 Oxygen requirement aerobic anaerobic 3 pH how acidic environment is most live in aqueous 4 Water availability need water to survive b c all living are water based salt and sugar make water availability low 5 Solute concentration Effects of temperature on growth growth rate how long it takes microorg to grow one cell two cells as you increase temp growth rate increases up to the optimum past optimum temp denaturation of proteins and loss of enzyme activity time is shortest at optimum temp fastest growth minimum temp no growth below this temp max temp no growth above this temp org dies Temperature ranges 1 Psychrophiles low temps ie salt water water under high pressure near bottom of ocean 2 Mesophiles optimal temps 37C associated w us b c body temp is 37 ie E coli 3 Thermophiles heat loving ie hot springs 4 Hyperthermophiles extremophiles ie volcanic structures at bottom of ocean most archaea pH 1 Acidophile like acidic 2 Neutrophile like pH 7 3 Alkalophile like basic Other microbial lifestyles 1 Halophile high salt conditions 2 Osmophile low water availability homemade jam which has massive amt of sugar limited water more likely fungi than bacteria 3 Piezophile High Pressure Facultative anaerobes tend to have more growth on oxygenated side can switch b w metabolism that uses O2 and one that doesn t use O2 can generate more ATP with O2 metabolism Aerotolerant anaerobes can survive in presence or absence of O2 in either case does NOT use O2 as part of metabolism evenly distributed General culture media 1 defined media all components quantified list of very specific ingredients 2 complex media undefined components extracts of materials dyes tryptone agar digest of proteins one 3 enriched media complex media for growth of fastidious organisms need certain nutrients need combination of certain ingredients to grow 4 nutrient media general growth media often complex ex TSA 5 minimal media contains minimal requirements for growth 6 selective media allows some to grow but eliminates others 7 differential media has indicators that highlight differences in physiology ex pH indicators Lecture 7 Blood agar enriched and differential medium alpha hemolysis some rupture green brown colonies beta hemolysis destroy RBC as they grow clear gamma hemolysis grow on media but RBC not affected no clearing Carbohydrate tubes liquid differential media has pH indicator neutral red acidic yellow uses glucose lactose fructose etc if it ferments media will turn yellow b c alcohols acids are produced MacConkey selective and differential medium selects for gram negative and inhibits gram positive growth this is b c it contains bile salts and crystal violet things G can t grow in presence of pH indicator and lactose also in medium colonies turn pink if org ferments lactose medium might also turn darker pink e coli colonies grow colorless or yellow if it doesn t ferment lactose salmonella bacterial metabolism catabolism use energy anabolism biosynthesis what do bacteria need to grow carbon source need carbon in many parts of cell DNA bilayer cell wall energy source required elements H N O P S Na K Cl Fe Mg Ca Cu Mn Se Zn photoautotrophs use light and CO2 plants algae cyanobacteria use H2O to reduce CO2 make O2 as byproduct get fixed carbon organic photoheterotrophs use light to make ATP not capable of fixing CO2 need source of outside C chemoautotrophs can break down chemical compounds to get energy from them get enough to fix CO2 into organic forms that can be used chemoheterotrophs aerobic respiration most animals fungi protozoa bacteria anaerobic respiration some