MICROBIAL WORLD AND YOU Flashcards
5 types of microbes
Bacteria, fungi, protozoa, algae and viruses
What produces can microbes produce?
insulin, cellulase ect..
What chemical products can microbes produce?
ethanol, acetone and vitamins
How are microbes useful
Prevent food spoilage, can prevent disease and epidemics
Genus
Capitalized
ex: Escherichia, Staphylococcus ect.
Bacteria
- Prokaryote
- Peptidoglycan cell well (enclosed)
- Binary fushion for reproducing and dividing
- Single cel organism
Archea
- Prokaryotic
- found in extreme enviornment
- 3 groups: methanogen, extreme halophiles, extreme thermophiles
What is a methanogen
bacteria that produces methane as a waste produce from respiration
What is an extreme halophile
bacteria that lives in extremely salty environment
What is extreme thermophiles
bacteria that lives in extremely hot environments
Fungi
-Eukaryotes
- can’t go through photosynthesis
- reproduces sexually and a sexually
What is the most common type of fungi
Mold called mycelia
- cottony growth found typically on bread
Protozoa
- Eukaryotes unicellular
- lives as a free entity or as a parasites
- can be mobil using flagella, cilia, or pseudopods
Protozoa energy source
Light as energy and uses CO2 to produce sugar
Algae
- Eukaryotes that are photosynthesized
- Reproduces sexually and asexually
- cell well made of cellulose
Where is algae found
Salt water, fresh water, soil and some plants
Algae important role
Balancing nature b/c it releases O2 and carbohydrates
Viruses
-Acellular
- Surrounded by a protein coat
How does viruses reproduce
- By cellular machinary using other organisms
Multicellular animal parasites
- Eukaryotic
- 2 main group
- Helminths are microscopes
What are the 2 main groups of multicellular animals parasites
- Flatworms
- Roundworms
What are the 3 domains of organisms
-Bacteria
- Archea
- Eukarya
Bacteria
cell wall contains peptidoglycan
Archea
Cell wall (if any) lacks peptiodgylcan
Eukarya
Fungi, plants, animals, protist
Eukaryotic fungi
- unicellular yeast
- multicellular molds
- mushrooms
Eukaryotic plants
- Mosses
- ferns
- flowing plants
Eukaryotic animals
- sponges
- worms
- insects
- vertebrates
Eukaryotic protist
- Slime mold
- protozoa
- algae
Robert Hook
- All living things are composed of cells
- Made a crude microscope
- lead the discovery of cell theory
Leeuwenhoek
- First to observe live organisms w/ microscope
- Animalcules
Redi
- Set out to disproved spontaneous generation combustion
- 2 jar experiment: one was left open and the other was sealed shut. The open jar produce maggots and the closed one didn’t
Spallaniza
- “Vital source” was needed for generation
Pasteur
- Disproved spontaneous generation “S-shaped flask experiment)
- Proved that microorganism in the air contaminate and cause microbes
- Fermentation
- Pasteurization
Jospeh Lister
- First physician to preform aseptic technique during surgery
Robert Koch
- Directly linked specific microbes to specific diseases
- Kosh postulate: step by step why to isolate bacteria
Jenner
- First vaccination
- Cure smallpoxs using cowpox
- Discovery that is you get the virius once its virulence factor decreases
Ehrlich
- Magic bullet
- used for chemothearpy
- Find a way to harm the pathogen only and keep the host safe
- Synthetic drugs
- Discovered Salvarson which is used to fight against syphilis
Flemming
-Discovered antibiotics
- observed penicillin
Biogenesis
Theory that all living cells come from existing cells
Genomics
Study of genes and their functions
Microbial ecology
- study of relationships between micrcoorganisms and their environment and how they interact with plants/ animals in various environments
Conjugation
the process of genetic information being tranferred from one bacterium to another
Bioremediation
the process of using bacteria to remover toxins
- from underground wells, chemical spills, toxic waste sites oil spills ect
Recombination DNA
used to produce natural proteins, vaccines and enzymes
Gene therapy
-Method of recombination DNA
- Inserting a missing or replacing a defective gene in humans
- uses a harmless virus to carry the gene into the host
Pasteurization
- The application of applying high heat for a short amount of time to kill harmful bacteria in beverages
Normal microbiota
- Acquired as newborns
- May colonize permentant residents or transient microbiota
- only colonized where their are proper nutrients and the right environment
- pervent growth of pathogens
What vitamins does the normal microbiota produce growth factors for
Vitamin B and K
Resistance factors for normal microbiota
Immunological benefits of normal microbiota
bacterial antagonism
Is biofilm harmful or helpful
Both
How is biofilm helpful
-Can protect mucous membrane from harmful microbes
-source of food in lakes
How is biofilm harmful
- can clog pipes and medical devices
- cause infection
where can you find biofilm
On teeth, on rocks in lakes, on medical devices
What is biofilm
- A thin layer of slime that covers surfaces
- its made of bacteria from the same species or a group of species
How can the body destroy biofilm
- By fever, white blood cells, inflammatory response, antibiotics
What are the types of light microscopy
- Compound
- Darkfield
- Brightfield
- Phase-contrast microscopy
- Differential interference contrast
- fluorescence
- confocal
Compound microscope
- Standard microscope
- enlarge appearance
- 40x, 100x, and 400x
- Shorter wavelengths to provide greater resolution
Bright field
- Brightly illuminated background
- dark specimen
-Used to see visualized stained specimen
Dark field
- Dark background
- Light visible speicmen
- cant be stained the stand way
- opaque disk blocks out the light
- used to examine unstained microorganisms in liquid
Phase-contrast
- examines living organisms and internal cell structures (ex. DNA)
Differential interference contrast
-Specimen is brightly colored and appears 3D
-Higher resolution than phase contrast
Fluorescence
- Uses UV light (short wavelengths)
- used as a diagnostic technique to detect antigens in the body (ex. syphilis, rabies, tuberculosis ect.
-Fluorescent antibody and immunofluorescent - cells maybe dye with fluorochrome if the dont naturally fluoresce
Confocal
- cells are stains with fluorochrome dyes
- 3D image is made with a computer (stock images, digital images)
- Used to examine cellular physiology
- short wavelengths (blue)
Two-photon microscopy
- cells are dyed with fluorochrome dyes
- long wavelengths (red)
- study living cells ip to 1nm deep
Scanning acoustic
-Measures sound waves from specimen
- used to study cells attached to surfaces
- cancer cells, artery plaque and bacteria biofilm
Electron microscopy
-Uses electron instead of light
- shorter wavelength
- used for images too small to be seen with light microscopes (virus)
- 2 types: transmission and scanning electron
Transmission electron
- can be stained with heavy metal salts for contrast
10pm resolution - Specimen is on a copper mesh grid
- used to study the very smallest specimens
- shadow casting ( helps determine actual size)
- Disadvantages
- very thin layers, no 3D aspect, specimens must be fixed, dehydrated and vacuumed which could cause damage
Scanning electrons
- provides 3D view of the specimen
- used to study the surface structures of intact cells and viruses
Scanning tunneling microscopy
- used a thin tungsten probe to scan specimens
- produces images that are used to reveal bumps and depressions of the atom on the surface of specimens
- Provide great images of molecules like DNA
Atomic force microscopy
- Metal and diamond probe that gently forces down onto the specimen
- creates a 3D image
- used to image biological substances (atomic detail) and molecular process of fibrin (a componet in blood clots)
Basic dyes
-positive ions
- crystal violet, methylene blue, malachite green and safranin
Acidic dyes
- negative dyes
- eosin, acid fushsin, and nigrosin
Simple stains
- highlights the entire microorganism so cell shape and basic structure is visible
- uses methylene blue, carbofuchsin, crystal violet, and safranin
Differential staining
-Gram staining
- postivite and negative staining
Acid fast staining
- Used to identify all bacteria of the Mycobacterium
Special stains
- used to stain specific parts of microorganisms
- negative staining, endospore staining, flagella staining
Negative staining
- For capsules
- doesn’t accept biological dyes
- appears as halos around the bacterial cell
- used to determine the virulence of the organism
Endospore staining
- uncommon in bacterial cells
- ordinary methods of staining wont penetrate the endspore wall
- malachite green is the primary stain
- safranin is the counter stain
Prokaryotes
- bacteria cell wall: peptidoglycan
- archaea cell wall: pseudomurein
- 1 circular chromosome not in a membrane
- no organelles or histones
- Divides by binary fushion
Eukaryotes
- Polysaccharide cell well if present
- Paired chromosomes
- has organelles and histones
- Divides by mitosis
Shapes of bacteria
- Coccus
- Bacillus
- Spiral
- Star-shaped
- Rectangular
Coccus
Spherical/ circles
Bacillus
Rods
Spiral
Vibrio: comma
Spirillum: external flagella
Spirochete: endoflagella
Star-shaped
-from food vacules
Spherical shaped
- from in nature
- takes a lot of energy to maintain
Pairs of bacteria
-Diplococci
- Diplobacilli
Cluster of bacteria
- Staphylococci
Chain of bacteria
- Streptococci
-Streptobacilli
Group of bacteria
Tetrads
Cubelike group of eight
Sarcinae
Glycocalyx
- Sugar coating
- sticky, gelatious polymer
- A substance prokaryotes produce on thier surface
-made inside the cell - described as a capsule
What is glycocalyx made from
- peptides
- polysaccharides
- or both
What is a capsules
- important contributor to bacterial virulences
- protects pathogens from phagocytosis
How is glycocalyx important to biofilm
- helps biofilm adhere to their surface and the bacteria to each other
Extracellular polymeric substance
- helps facilitate communication
- enables cells to attach to various surfaces
How does glycocalyx protect cells
- protects cells from dehydration
- inhibits nutrient movement outside the cell
Flagella
- long filaments appendages that propel bacteria
Types of flagella
- Atrichous
- pertitichous
- polar
- monotrichous
- lopotrichous
- amphitrichous
Atrichous
- bacteria that lack flagella
Pertitichous
- flagella all around the cell
Polar flagella
- flagella on one or both poles of the cell
Monotrichous
- single flagella on one pole of the cell
lopotriichous
- a bundle of flagella coming from one pole of the cell
Amphitrichous
- flagella at both poles of the cell
3 basic parts of flagellum
- Filament: long outer region
- Hook: attaches to filaments
- Basal body: anchors flagellum to the cell wall and plasma membrane
Flagella runs vs swims
Runs: interrupted by periodic, abrupt and random changes in directions (tumbles)
Swims: no interruptions
Chemotaxis
- Chemical stimuli invloved
Phototaxis
light stimuli invloved
Atrractants
Chemotactic signs are positive
Repellent
chemotactic signals are neg.
- results in multiple tumbles
Archella
- Knoblike structures that anchor archella to the cell
- Pili and archaella use ATP for energy
- consist of glycoproteins called archellin’s
Axial filaments
- spirachetes: group of bacteria with a unique shape and structure and mobility
- Spriochetes move this way
Fimbriae and Pili
Pilian is the protein that arranges around a central core and are divided into 2 : pili and fimbriae
- Pili mobility involves gliding and twitiching
- fimbriae can occur at the polor around the entire cell
- Fimbriae: has hairlike appendages that allow attachment
Conjugation pili
DNA transfer from one cell to another
Gram- positive cell walls
- Teichoic acid
- lipoteinchoic acid links cell wells to plasma membranes
- carries a negative charge
- polysaccharides and teichoic acid provide anitgenic specificity
- produces exotoxins
- high susceptibility to penicillin
- disrupted by lysoxymes
Gram- negative cell wall
- outer membrane and the plasma membrane
- outer membrane is made of ploysaccharides, lipoprotiens, and phospholipids
- produces exotoxins and endotoxins
- low susceptibility to penicillin
Damage to the cell wall
- lysozymes hydrolyzes bOnds in peptidoglycan (GRAM P)
-Penicillin ( GRAM P) - Spheroplast
- Irregular shaped cell walls
Chemical and physcial requirements for growth
Chemicals:
-C, N, S, P, O
- Trace elements
- Organic growth factors
Physical:
- Temp
- pH
- Osmotic pressure
Temperture
Psychrophiles: cold
Mesophiles: moderate
thermophiles: hot
Psychrophiles
- 0’ C
- Slowly degrades food
- slime on food
- off taste or color to food
Mesophile
-25-40’ C
- Host temp
- pathogenic bacteria is usually 37’ C
- Food spoilage and disease organism
Thermophiles
- 50 - 60’ C
-Cant grow below 45’ C - Not considered a health problem
Hyperthermophiles
- 80’C or higher
- hot springs w/ volcanic activity
- sulfur in their metooblic activity
pH of bacteria
- Most bacteria is neutral (6.5 -7.5)
Acidic bacterias
- acidphiles
- pickles, sauerkraut, most cheeses and bacteria fermentation
- Molds and yeast
Osmotic pressure in bacteria
- Pressure needed to stop the movement of water across the plasma membrane
- get nutrients from surrounding water
- plasmolysis: shrinkage of cytoplasm
Types of movement across the membrane
- Passive process
- Active processes
Passive process
- moves from high to low concentration
- goes with the flow
- no energy needed
EX: simple diffusion and facillitated diffusion and osmosis
Simple diffusion
- from high concentration to low concentration
- continues till equalilbrium is reached
Facilitated diffusion
- transporter protein helps with moving across the membrane
- transport ion and large molecules
Osmosis
- the movement of water across the membrane
- high water to a low area of water concentration
- through the lipid bilayer
- aquaporins ( water channels)
Active processes
- Active transport
Active transport
- requires ATP and transport protein
- Low concentration to a high concetration
Aerobes
Uses oxygen for nutrients
anaerobes
dont need oxygen
obligated aerobes
-require oxygen to live
- poor solubles
Facilitated anaerobes
- can grow in the absence of oxygen
- can use oxygen if prensent
with oxygen effiecncy is decreased
anaerobes
- cant used molecular oxygen for energy reaction
Endospores
- Resting cells when nutrients is depleted
- resistant to desiccation, heat, chemicals and radiation
- sporulation: formation of endospores
- germination: endospores return to a vegetative state
Culture medium
- material prepared in a lab for the growth of microorganism growth
