- Some are unicellular
- Mostly aquatic with chloroplasts and cholorophyll
ex: spirogyra, diatoms, chlamydomonas
Ways to move: cillia (paramecium), flagella (euglena), pseudopods (amoeba) and Phylum Apicomplexa
- Photosynthetic prokaryotes
- No chloroplasts
- Produce Oxygen (O2)
Anabaena (Pond Organism)
- A gliding cyanobacteria (belongs to domain Bacteria)
- Heterocyst: fixes nitrogen: take Nitrogen gas from air
- They have photosynthetic pigments: give off a blue-green hue.
- Trichromes: found in chains, No chloroplasts, Produce Oxygen and Use Nitrogen Gas.
Spyrogyra (Pond Org)
- Part of Algae group: contain distinctive spiral chloroplasts.
Diatoms (Pond Org)
- Photosyn unicellular Prokaryotes:belong to ALGAE group.
- Either centric or pennate (billaterally symetrical and elongated)
- Pigment: fucoxanthin--gives off a golden brown hue.
Giardia Lambia Cysts:
--> what is a cyst?!
--> where is it found, how is it transmitted?
inactive form, non-motile and resists DISINFECTION.
-oval shape, 4 nuclei
Shed in Feces, transmitted in fecally contaminated water and by oral contact of food.
--> what is a Trophozoite?
--> common where?
- Trophozoite: Active-Feeding form
- Most common in duodenum; also found in stool
- Has two nuclei with karyosomes and axostyle-a line in the middle of the cell and 8 flagella
Plasmodium Falciparium (ring stage)
- Transmitted by mosquitos;
- cause malaria: fatal vessel obstruction and thrombosis.
- --sporozoite transmitted my mosquito bite
- --reproduces in liver THEN RBC's
- Ring stage-parasite in RBC.
Most found in vaginal area, transmitted sexually- STD: trichomoniasis
What are the groups of microbe organisms:
- Fungi (yeasts/molds)
--> 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)
Most useful-classifies bacteria into two large groups-gram positive and gram negative.
- 1. heat-fixed smear covered with crystal violet( Primary stain: gives its color to all cells).
- 2.Then dye is washed off, smear covered with iodiine and washed off so that both gram positive and negative bacteria appear dark violet.
- 3. Slide is washed with alcohol solution: decolorizing agent-removes purple from cells of certain species.
- 4. Alcohol is rinsed off ==> slide is stained with safranin (basic red dye). Blot dried.
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. :)
- 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)
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
- Reacts with oxygen, removed oxygen from medium
- --> good for growing bacteria
Two reasons to use agar?
can liquify at 100 deg celsius, 50 degrees water bath keeps it liquid and does not injure bacteria when doing pourplates. --Incubated at 100 deg friendly to thermophilic bacteria
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
What is the equation for calculating number of bacteria?
- N: total number of bacteria
- N0: number of cells at beginning/start
- n: number of generations
Direct Methods to count bacteria and their advantages/disadvantages:
- 1. Direct microscopic count:
- --> Advantage: fast;
- --> Disadv: count dead and viable (still reproducing/alive) cells
- 2. Standard Plate count:
- --> Adv: Only counts viable cells.
- --> Disadv: slow because you have to wait days
Indirect methods of counting bacteria: Two ways
ONE WAY: Turbidity
: Gets the relative number of all cells; complements standard plate count ("how cloudy")
- 1. Use spectrophotometer
- 2. Measure light absorbance of test tube with bacteria;
- 3. measurements are in Optical density (stay between 0 to 2)
**CORRELATES WITH STANDARD PLATE COUNT BECAUSE IT MEASURES DEAD CELLS ALSO*
- SECOND WAY: Dry weight or mass
- --> Advantages: Fast and good for clumping organisms
- --> Disadvantages: measures live and dead cells
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.
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
form by golgi complexes; store digestive enzymes
EPS: extracellular polymeric substance
a glycocalyx that helps cells in biofilm attach to target environment and allow bacteria to survive
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
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
-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
-found: teeth, rock in a pond, pet's waterdish
advantages of biofilm:
- prevents dehydration
- share nutrients
- protection from host immune system (antibodies or wbc phagocytosis)
pure substance that can be broken down into simpler substances (elements)
-two ore more elements joined together
Two or more atoms joined together
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.
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
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
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)
- 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.)