Microbiology

lack a membrane bound mucleus and organelles; about 1/10 the size of a eukaryote

single chromosome, a loop of double stranded DNA

• 1. proteobacteria
• 2. firmicutes
• 3. actinobacteria
• 4. cyanobacteria
• 5. chlamydiae
• 6. spirochaetes

gram - bacteria, includes many pathogens.  ex:  escherichia, vibrio, salmonella, neisseria, yersinia

firm skin, gram + bacteria.  ex:  streptococcus, staphylococcus, clostridium, bacillus, mycoplasma

soil borne, filamentus, resemble fungus; produce antibiotics.  ex:  streptomyces & actinomyces.  myc=fungus (but not a fungus it's a bacteria)

photosynthetic; formerly called blue green algae

1/2 the size of rickettsiae, most are pathogens, obligate intracellular parasites

helical cells, corkscrew.  ex:  syphilus & lyme disease

primitive, harsh living conditions, not pathogens

• 1. euryarcheota
• 2. crenarcheota

methanogens (produce methane) extreme halophiles (salt loving) hypothermophiles (above 80'c), thermoacidophiles (heat and low pH)

hyperthermophiles, hot springs and ocean vents

• 1. bacillus - rod shaped
• 2. coccus - spherical
• 3. coccobacillus - between rod shaped and spherical
• 4. vibrio - curved bacillus
• 5. square - tile like, very rare
• 6. spirillum - rigid spirals
• 7. spirochetes - flexible helix
• 8. pleomorphic - vary in shape

• 1. single - not connected to each other
• 2. pairs - diploid
• 3. tetrads - four
• 4. sarcina - cube
• 5. cluster
• 6. chains - strepto

appendage used for attachment, shorter than flagella; composed of pilin protein w/ adhesives attached (sticky)

• 1. sex pilus - bacterial conjugation, mating
• 2. fimbriae - attach cells to each other or the environment.  E coli use fimbriae to attach to urethra and migrate to bladder

bacterial motility

• 1. basal body - anchor to cell wall & membrane
• 2. hook - right angle bend, rotates 360'
• 3. filament - thread that extends out from cell, composed of flagellin protein

• run - counterclockwise, going straight
• tumble - clockwise cause them to spin, change direction

movement toward or away from a chemical

move to favorable O2 concentrate

sim to optimal light intensity

• monotrichous - single flagellum
• amphitrichous - flagellum on both ends
• lophotrichous - cluster on one end
• peritrichous - surface covered

on end of cell

periplasmic flagella, spirochestes have flagella inside of outer sheath, create "wiggle" movement

• polysaccharides outside of cell wall, gel-like
• protects cell from dessication (drying out)
• attachment
• appear moist (colonies), glisten

• capsule - organized, gelantinous, covalently bound to cell wall, virulence factor for pathogens. ex:  strep pneumonia - with capsule = sickness, without capsule = NO sickness
• slime layer - diffuse & irregular, tangled polysaccharide layer, sticky, biofilm

the cell wall and cell membrane

rigid, protect cell from lysis (withstand turgor pressure), maintain cell shape

thick layer of peptidoglycan with teichoic & lipoteichoic acid embedded in it

macromolecule of NAG & NAM

join NAM's, a lot of antibiotics don't let this happen (used on gram + bacteria)

"wall", attaches to NAM covalently, if it extend to cell membrane it is called lipoteichoic acid, may bind and regulate cations in/out, cell growth

• made up of two layers
•      * peptidoglycan
•      * outer membrane
•     

thin layer sandwiched between membranes

fluid between outer membrane and peptidoglycan

• 1. porin protein
• 2. lipoproteins
• 3. lipopolysaccharides 

transport

anchor the outer membrane to peptidoglycan

• extend out from outer membrane
•      * lipid A - anchor, pyrogen
•      * core polysaccharide
•      * O side chain (antigen) - your immune system "see" this.  ex: Ecoli O157:H7

• gram + cell wall w/ a high lipid content
• mycolic acid (waxy, tough to penetrate when staining)
• do not gram stain
• ex:  mycobacterium tuberculosis

• selectively permeable
• protective
• fluid mosaic model - not a static structure, can change to meet cell needs

fluid & dissolved substances

site of protein synthesis

dense region containing genome

• single chromosome
• 1N
• haploid
• single loop of double stranded DNA

extra loop of d.s. DNA, bonus genes for the cell, may include antibiotic resistance, exchanged during conjugation (mating)

storage or specialized

• 1. glycogen - store energy; carbon source
• 2. volutin - (metachromatic) granules - store phosphate
• 3. poly B hydroxy butyrate - store energy, carbon source

• 1. chlorosome - pigment for photosynthesis
• 2. magnetosome - composed of iron oxide, gram - cells, navigation
• 3. gas vacoules - rigid compartment, bouyancy

dormant, highly resistant to environment stressors, withstand high heat, drying, cold, UV radiation

formation of endospores, environmental trigger

calcium enters & water exits to dehydrate deposit dipicocolinic acid to stabilize the DNA & proteins

spore transforms to a viable vegetative cell

• 1. activation - brief exposure to heat or certain chemicals (reversible)
• 2. outgrowth - take up water, no turning back, transforms into vegetative cell, susceptible