Micro Cumulative: UNIT 1
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What are the groups of microbe organisms:
- Fungi (yeasts/molds)
Established by Carolus Linnaeus
Two names: Genus + Speccific eptithet(species--always lowercased)
ex: Staphylococcus aureus OR Staphylococcus aureus
--> cell walls?
--> how do they eat?
- Unicellular prokaryotes (means DNA is NOT in a nuclear membrane)
- Either Baccillus (rodlike), coccus (sphere), spiral (corkscrewed)
- Cell walls: Peptidoglycan (carb + prootein complex)
- Reproduce by binary fission-divide into two equal cells
- Some can photosynthesize, while others get food inorganically.
--> what are three groups?
- Prokaryotic-No peptidoglycan
- 3 groups: methanogens, extreme halophilles (salt lovers) and extreme thermophiles (hotsprings)
- **NOT pathogenic
--> cell walls?
--> uni/multi cell?
--> 2 types and characteristics?
- Uni or multicellular
- cell walls: chitin
- yeast: unicellullar
- mold: reproduce either sexually or asexually
--> uni/multi cell?
--> how do they move?
--> how do they survive?
- Move with: flagella, pseudopods, cillia
- environments: free living or parasitic
- Some can photosynthesize (euglena)
--> cell wall:
--> most common where?
--> how do they help envir?
- Photosyn. Eukaryotes
- usually unicelluar
- cell wall: cellulose (carb)
- Most found: in fresh water, salt water, and soil
ex: spyrogyra, diatoms,
**Produce O2 and carbs for other organisms.
--> Nucleus memb?
--> where do they reproduce?
- Accellular o.0
- Either only have DNA or RNA in a lipid membrane (neither euk/pro)
- Reproduce in hosts
multicellular animal parasites
Includes: flat and round worms
Three Domains & 4 kingdoms:
- 2. Protista: protozoa & algae
- 3. Fungi
- 4. Plants (no microbes)
Bacteria that retain the dye after decolorizing alcohol
-->thicker peptidoglycan cell wall,dye and iodine enter and form CV-I complex-larger molecule than crystal violet molecules that entered, so it cannot leave==> so alcohol does not wash out the dye.
Bacteria that LOSE the dark violet color after decolorization
must be added to stain these pink to counter the original purple stain so called a "counterstain"
- --> contain layer of lipopolysaccharide as part of cell wall (alcohol wash disrupts this outer layer, and the "CV-I" complex is washed out through the thin layer of petidoglycan)
- -->must be redyed with safranin. :)
Upper respiratory Bacterial infection caused by Corynebacterium diphtheriae
Begins with sore throat and fever, neck swells
- -often affects throat(pharynx) and larynx (voicebox)
- -creates a pseudomembrane of fibrin, dead tissue and bacterial cells that clogs throat/air passage
- Microbe: Corynbacterum diphteriae
- --> gram positive
- --> non-endospore-forming rod
- --> cell arranged: palisades
- DTap Vaccine: for children, "D" stands for Diphtheria toxoid (inactivated toxin) that allows body to make antibodies against diphtheria.
- --> "Toxoid vaccine" based on inactivated exotoxin
teens and adults (combined with tetanus shots)
Droplet transmission; resistant to drying (coughing, sneezing, talking)-also skin contact with humans
- Toxic proteins secreted by bacteria;
- produces strains that cause disease.
- Related bacteria are present on skin and are not pathogenic.
Mortality and complications from Diphtheria
- Suffocation/death-children mostly
- Heart/peripheral nerve damage
Diphtheria Diagnostic methods & treatments
Diagnose: throat swab culture; PCR (polymerase chain reaction-method to make many DNA copies) to grown and study
treatments: Antibiotics & antitoxins (penicillin/erythromycin)
Whooping cough; damages cilliated cells in respiratory system
- -paralyzes the cilliated cells
- -cause inflammation
- -impairs immune response
- caused by Bacterium "Bordetella pertussis"' obligatory aerobic
- gram negative
Pertussis Mode of Transportation
Transportation: respiratory droplets (coughing/sneezing)
The stages of Pertussis:
First Stage (catarrhal stage) resembles common cold- coughing, sneezing, low fever (100 deg F)
Second Stage (Paroxysmal stage): severe prolonged coughing fits, may make "whoop" sounds; difficult to cough up phlegm when cilliated cells are destroyed.
Third stage: coughing eventually become less frequent and less severe (convalescence)
- -break ribs
- -brain damage/death in babies by coughing
Diagnosis: culturing bacteria (swab and identify)
- 1. First stage: give antibiotics
- 2. second stage:
- 3. DTaP: subunit of pertussis (begins at 2 months old, given 3 shots total)
- 4. Boosters for teens
- 5. Tdap: adults
- 5. Vaccine rate: 93% herd immunity (reduced chance of infection of vulnerable individuals if a certain high percentage of individuals in the populations are vaccinated or immune.)
Prokaryotes: distinguishing characteristics
- 1. Dna has no enclosed membrane
- 2. lack membrane enclosed organelles
- 3. cell walls are complex polysacharide peptidoglycan
- 4. Divide with binary fission
- 1.Has nucleus to sep dna from cytoplasm
- 2. have many membrane enclosed organeles
- 3. chemically simple cell walls.
- 4. cell division: mitosis.
Prokaryote vs Eukaryote Structures (image)
Plasma Membranes: Prokaryote vs. Eukaryote
BOTH have it!
similarities: phospholipid bilayer with proteins, separates cells from outside
Differences: not applicable
Cell Wall: Prokaryote vs. Eukaryote
- Bacteria has peptidoglycan;
- Fungi: Chitin
- Plants&Algae: Cellulose
: structural support, resists bursting, made of polysaccharides
: Chemical composition; some eukaryote do lack cell walls
Chromosome (genetic material)
: Circular, only one chromosome in "nucleoid" region
: Linear, variable number of chromosomes/associated with histone protiens
- Similarities: Made of DNA
- Differences: Different (?) and organization
Nucleus: Prokaryote vs. Eukaryote
- Prokaryote: NONE
- Eukaryote: Present :D
**THIS IS THE DIFFERENCE**
Flagellum: Prokaryote vs. Eukaryote
: Rotational motion in Bacteria
: whiplike in animals
- Similarities: Locomotion
- Differences: Diff type of motion & chem compositon
Ribosomes: Prokaryote vs. Eukaryote
- Prokaryote: Present
- Eukaryote: Present, some associated with RER
- Similarities: Protein synthesis
- Diffs: prok have smaller ribosomes
Membrane Bound Organelles: Prokaryote vs. Eukaryote
- Prokaryote: NOT PRESENT,
- Eukaryote: Rough ER, Mitochondria, Golgi Body, lysosomes, chloroplast
- Differences: Prok lack; euk often have several membrane bound organelles
Capsule (pg 70)
- Firmly attached to cell wall (made of glycolax-gelatinous polymer)
- -protect pathogenic bacteria from phagocytosis :(
- another type of glycolax;
- Loose, thinner, flexible attached to cell
- -Helps bacteria attach to surface
Endospores (70. 95-97)
-purpose and characteristics
Resting structures formed by some bacteria, allows for survival during adverse environmental conditions (dry conditions)
- very little water
- resistant to heat, uv rays and disinfectants
- Components: cytoplasm, plasma membrane, ribosomes, peptidoglycan, spore coat (protein) and dipicolinic acid
: terminal(very end), central and subterminal (almost end)
ex: clostridium tetani
- 1. DNA is replicated
- 2. Endospore forms when plasma membrane, peptidoglycan layer, and spore coat surround DNA
- 3. endopsore is related as vegative cell disintegrates
return of endospore to it's vegetative state
1. How do you get rid of endospores?
2. How is an endospore diff from a begetative cell?
3. can bacteria reproduce by using endospores?
4. what would happen if an endospore got into bloodstream of a patient?
5. Do we need to strilize our food to get rid of endospores?
- 1. calibrate by increasing or decreasing temp
- 4. spermination
- 5. Pasteurization, canned food: get rid of botchulism endospores
EPS: extracellular polymeric substance
a glycocalyx that helps cells in biofilm attach to target environment and allow bacteria to survive
Endoplasmic Reticulum (ER) & RER
- Nuclear envelop attached to Endoplasmic Reticulum (ER)
- --surface for chem reactions and transport network.
- --RER: protein synthesis/transport
flattened sacs (cisterns); fuctions in membrane formation & protein secretions
form by golgi complexes; store digestive enzymes
memb enclosed cavities; give rigidity to plant cells
- primary ATP site production;
- contain 70S ribosomes & dna.-multiply by binary fission
polymer consisting of NAG (N-acetylglucosamine) & NAM (N-acetylmuramic acid) and short amino acid chains; penicillin interferes with this wall
--in gram positive cell walls; crystal violet combines with peptidoglycan but decolorizer removed the lipid outer memb of gram negative bacteria and washes out crystal violet.
Gram neg walls: thin peptidoglycan layer and a lipopolysaccharide-lipoprotien-phospholipid layer (-.-)
Gram Negative cells (chemical structure)
- -MUCH more complex-Thin layer of peptidoglycan
- -LPS (lipopolysaccaride)
- -Periplasms with chemoreceptors: gel like fluid between outer membrane and the plasma membrane
- -NO teichoic acids;
- OUTER membrane: contains LPS, lipoprotiens and phospholipids
- --gives wall strong neg charge
- --provides barrier to antibiotics, digestive enzymes,and dyes
- --Porins: channels allow nucleotides, amino acids
Gram Positive Cells (chemical structure)
- -Many layers of peptidoglycan
- -Thick ridgid structure
- -teichoic acids: alcohols (glycerol) and phosphate; gives wall antigenic specificity to allow group into "gram pos" cells
How do Gram stains work?
-Crystal violet purpose
-Alcohol effect to both walls
- ADD what dye after, what kind of dye is this?
-Based on differences between cell wall structure (type of differential stain)
Crystal violet (primary) stain both cells
Iodine: forms large crystals with dye that are TOO large to escape through wall
Alcohol: dehydrates peptidoglycan of gram positive cells and make it more impermeable to crytal violet-iodine. BUT on gram negative: the alcohol dissolves the outer membrane of gram negative cells and even leaves small holes in the thin peptidoglycan layer SO THAT crystal-violet-iodiine leaves!
This is why safranin must be added to stain gram negative cells (turn them red)--contrasting stain
Tetra peptide Side Chain
- Composed of NAG & NAM
- -NAG: N-acetylglucosamine
- -NAM: N-Acetylmuramic acid
coccus, spiral, star, pleiomorphic
- Rod/bacillus: cylinders
- coccus: sphere
- spiral: spirillium (w/flagella) or spirochete (axial filaments-rotate)
- pleiomorphic: many shapes (corynebacterium diphtheriae-cause diphtheria)
Bacterial Cell ARRANGEMENTS:
- the ways cell stick together:
- 1. strepto: chains of cells
- 2. tetrad: group of 4 cells
- 3. stahylo: grape like clusters
- 4. palisade: picket fence
- 5. diplococcus: two circle oo
- a. nutrient storage:
- --> ex: polysaccharides granules for store starch
- --> lipid inclusions store lipids
- -->sulfur bacteria store sulfur as energy source
- b. metachromatic granules with phosphate (turn red): inorganic phosphate storage
- --> used to diagnose Corynebacterium diphtheriae
contains iron compounds, use to orignet to magnetic fields
Pili and Fimbriae
Pili: straight, hairlike, gene transfering
Fimbria: straight hairlike for attachment ex: neisseria gonorrheae
Parts of flagellum?
long appendages that propel bacteria
single flagellum at one pole
: flagella distributed over entire cell
flagella at both poles of the cell
: protein that is the main component of the filament
- Main parts of flagella:
- Basal Body-anchored the whole flagellum to the cell wall and PM
- Hook: rotates
-Community of bacteria; form at liquid-solid interfaces; slime layer (extracellular polymeric substance-EPS
:helps bacteria attach to surfaces)
-protected from antibodies and antibiotics; wbc's create inflammation
teeth, rock in a pond, pet's waterdish
- advantages of biofilm:
- prevents dehydration
- share nutrients
- protection from host immune system (antibodies or wbc phagocytosis)
Biofilms Review Questions:
1. Explain how a biofillm protects bacteria from antibiotics
2. Best way to get rid of biofilms
- 1. Protective barrier
- 2. Physically remove them
- Bacteria organize into communities using chemical communication to make biofilms,
- disruption will allow for prevetnion
removes water; convalently link molecules (CONDENSATION)
ADD water to break apart two covalently linked molecules
Four groups of biological molecules?
- 1. carbs
- 2. Lipids
- 3. Proteins
- 4. Nucleic acids
Functions: energy source/storage, carbon source and part of cell structure
- -Composed of C,H,O
- -Hydrophillic (waterloving)
: hexose, pentose
(glucose+galactose) and sucrose
/canesugar (glucose and fructose)
(plant/algae cell walls), starch
(energy storage), petidoglycan
(bacterial cell walls)
Lipids functions and structure::
2. fatty acids
3. saturated vs. unsaturated
Fn: energy storage, cell memb components
Structure: C,O,H and sometimes P & S
-HydroPHOBIC (dont dissolve)
Triglycerides: 3 carbon glycerol + 3 Hydroxyl (OH) groups
Fatty acids: C-H chain + carboxyl group at the end
saturated fatty acids: only single bonds b/w carbons (fats: butter and shortening)
Unsaturated: double or triple bonds give it a kink (oils)
Phosoplipids: two fatty acids + glycerol + phosphate group + "R" group (hydrophillic)
Sterols: 4 connected carbon rings, not composed of fatty acids, hydrophoics
: cell structure (flagella, cytoskeleton, enzymes, chem signals)
: transporters in cell membranes (botulism toxin)
- Amino acid: building block of proteins:
- --> amino group (NH2)
- --> carboxyl group (COOH)
- --> R group connected to central carbon
created by dehydration synt. b/w 2 amino acides; spacial type of covalent bond
: short chain of amino acids; Polypeptides (structure: primary, secondary, tertiary and quaternary sturcture)
DNA: genetic code/template fro protein making
RNA: helps make proteins
- Nucleodtide has 3 parts:
- 1. 5C sugar (ribose/deoxyribose)
- 2. Phosphate backbone(PO42-)
- 3. Nitrogenous base (can form H bonds)
ATP (adenosine triphosphate):
- DNA bases: Adenine, guanine, cytosine, and thymine
- RNA bases: uracil instead of thyamine
function as energy "currency"; stores and provides chemical energy, made out of ribose, adenine and 3 phosphates linked together.
Growth Condition Factors of Microbes
- A. Temperature
- B. Liquid water-with vapor
- C. pH: most enjoy neutrality; peptones used as buffer salts in mediums
- D. Nutrients: Carbon (auto/hetero) or Electrons (Chemotrophs)
- E. Oxygen levels or Lack of it (need a balance)
Optimal, Minimal, Maximal
- Minimum: lowest temp at which species will grow.
- Optimum: best temperature for growth.
- Max: highest temp at which growth is possible.
- Likes 0-20 deg C
- 15= optimum
- -cold-loving microbes
- -found in oceans/polar regions.
- -unlikely to spoil food
Grow slowly at low temps but optimum from 20-30
-Responsible for food spoilage; grow well at refrigerator temps though cold temps slow down reproductive rates.
: 20-40 deg temps "middle" (room)
- -moderate-temperature loving microbes
- -live in terrestrial/aquatic areas, plants & animals
- - may cause disease: likes body temp of host
: 40 degs Celsius and higher
- - heat-loving microbes
- -endospores: fromed by these bacteria; may survive heat treatments given to canned foods.
- -found: hot spring run offs; compost piles
- ex: Thermus aquaticus: yellowstone
- Optimum: Higher than 80 deg C (boiling/acidic water)
- Domain: Archaea; different from bacteria (don't denature)
Acidophiles vs. Alkaliphile
- Bacteria tolerant to acidity
- -Molds: pH 5; Lactobacillus bacteria
-->importance of osmotic pressure?
--> extreme, obligate and faculative
--> osmotic pressure: loss of water causes plasmolysis (shrinkage); imp b/c inhibits cell growth and preserve food
Extreme halophiles/obligate(require) vs. Faculatative halophiles (don't require but won't hurt either)
Oxygen: obligate aerobes, facultative anaerobes, obligate anaerobes
Nitrogen :Dna & RNA synthesis; nitrogen fixation by cyanobacteria (anabaena)
Sulfur: synthesize vitamins-biotin, thiamine
Phosphorous: ATP synthesis; nucleic acids and phosopholids of cell membranes
Use Oxygen; extract more energy from nutrients than anaerobes.
- a.Obligate/Strict Aerobes: MUST have it.
- --> disadvantaged b/c not much oxygen in water
b. Microaerophilic: uses small amounts
- a. Obligate: bacteria that are unable to use molecular oxygen for energy yielding reactions; require oxygen to live
- ex: clostridium (known for botulism & tetanus)
: cant use oxygen for growth, but can tolerate it.
-ferment carbs to lactic acid. ex: lactobacillus makes pickles/cheese
Forms water to remove oxygen
Bacteria that have developed or retained the ability to continue growing WITHOUT oxygen.
microbe communities; in slime
(matrix of polysaccharides with DNA/proteins)
- -quorum sensing: allows bacteria to coordinate activity and group together
- ex: plaque, pond rocks
- -work cooperatively on same task
- -primitive circulatory systems: incoming nutrients and waste channels
- -1000x More resistant to microbicides; form on medical devices
- -protected by antibodies, WBC phagocytosis and antibiotics
: block quorum sensing, incorporate antimicrobial into possible biofilm surfaces; must physically remove them
Binary Fission Diagram
Shows binary fission (bacteria) or mitosis (fungi) reproduction
- a. Lag Phase: Preping/intense activity; no increase
- b. Log Phase: exponential increase
- c. Stationary Phase: equilibrium (deaths balance new cell production)
- d. Death phase: decreasing population
Nutrional names for organisms
: use lights a primary energy souce
: depend on oxidation-reduction reactions of inorganic/inorganic compounds for energy.
- Autotrophs (self feeders: use CO2)
- --> litotrophs(rock eaters)
- Heterotrophs (use organic carbon source)
- --> organotrophs
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