Exam 1 Flashcards
What percent of microbes are pathogenic
3%
Microbiology
Scientific study of microscopic organisms and viruses.
What is normal flora?
Microbes that live in or on your cells
Ratio of microbes to human cells?
10xs or 10:1
How many different species in our flora?
500-1000
Average weight of human flora?
3lbs
What do they mean by opportunists?
The microbe may take advantage which can lead to disease
When do you start acquiring flora?
During birth process, care givers, etc
What percent of o2 that we breathe is produced by microbes.
50%
How are microbes beneficial to plants
They are needed in the soil
How do cows, horses, sheep use microbes
To digest cellulose in their gut
How do ecosystems rely on microbes?
To enrich soil and degrade wastes
What products that we eat or use are produced by microbes?
Wine, beer, yogurt, cheese bread, nail polish remover, detergent, flavorings
Who invented the first microscope?
What was its magnification?
Robert Hooke
25x
Why were cells named cells?
What was the first thing Hooke viewed under the microscope?
Hooke saw open squares
Cork
Who first saw microbes
What did he read
What mag was his microscope?
Anton Von Leeuwenhoek
Hooked micrographia
200-300x mag
What are considered microbes? 6
Fungi(yeast, mold) Protists Protozoa Algae Bacteria/archae Viruses S
Define spontaneous generation
When was this believed?
Who was the first to challenge it?
Life arising from non living matter
A very long time before it was prove
Redi
What did redi’s experiment test?
What was his profession?
What did the experiment consist of?
What was the conclusion.
Spontaneous generation
Italian md
3 jars with meat in them, one open, one closed and one with gauze. There were inky maggots in the open jar.
Spontaneous generation false
What was pasteurs experiment?
How long did he incubate?
What was the conclusion?
He. Got some swan necked flasks.
Boiled some broth until it was sterile
Incubated flasks and checked everyday fore 18 months
No growth
Tilted flask, within hours microbes grew.
Spontaneous generation FALSE
How could Pasteur tell. If. Their. Was microbes. In. His broth?.
Cloudiness indicated microbe growth, clear meant now growth
How. Did. People control rate of. Infection from disease. In. The 1300s?
Quarantine
In the mid 1500s what was the new idea about how diseases were transmitted?
Italian md said via clothes, touch, utensils, etc
What was miasma?
Poisonous particles in the air transmitting diseas
Definite epidemiology
The study of where and when infectious diseases occur
Who was the guy who invented hand washing?
What were his observations?
He did he die?
A Hungarian doctor ignez sennel weis
29% vs 3% md side to midwife side women died of a fever
Suggested washing hands, it decreased death by 2/3
No one liked it, drove him crazy, he was fired left Vienna
Went insane and stabbed himself with contaminated scalpel, died with same fever
Who was the English md who studied a deadly diarrhea outbreak in London ?
What was his conclusion?
What was the disease?
John snow
Contaminated water source of infection
Cholera
What does vaccination do?
Prevents infectious disease
Who (nation) discovered a prevention to small pox?
How did they do it?
Did it work?
Chinese
Took scabs off dead my people blisters, ground them up and blew the dust into people’s noses
It worked!
What was the european approach to the Chinese vaccination?
Did it work?
Inserted scabs under the skin
It worked!
What fraction of kids died in the small pox outbreaks in the 1700s?
Before what age would they die?
1/3
3
What did Jenner observe and then test?
What did he write?
He many in England were vaccinated.
Observed that milk maids would get cow pox and then survive small pox
He injected the cow pus into a little boy and he lived.
Wrote pamphlets for doctors
Over 100,000 were vaccinated
What was needed to really see microbes?
More powerful microscopes
What did they see in the stool of cholera patients.
Bacteria
What experiment did Pasteur do that led him to believe that microbes are cause of infectious disease
The French hired him to find out what was making their wine taste bad, so he looked at it under the microscope saw bacteria. Told them to heat it up to kill everything and then add yeast.
Published his paper
What is the germ theory and who wrote it?
What three vaccines did he produce
MIcrobes are the cause of infectious disease
Pasteur
Chicken cholera, sheep anthrax, human rabies
Who thought of using phenol in the operating room? What caused him to try this? Whose paper did he read? How much did the death rate drop by? What is phenol? What did they later use instead?
Lister
Half of his patients were dying after surgery, wanted to up his odds
Pasteurs on spontaneous generations
the rate dropped by 2/3 when they dressed wounds with phenol
Phenol is caustic and highly toxic to human skin
Boric acid
Who wanted to verify the germ theory?
How did he do it?
Robert Koch
By using Koch,s postulates on sheep while studying anthrax.
What are kochs postulates? 4
- Find the same microbe in every case of the disease
- Isolate the microbe and grow it in pure culture.
- Inoculate a healthy host with pure culture and the identical disease must be produced
- Rue isolate the microbe from experimental host and compare microbe to pure culture, must be identical.
What is pure culture?
Only the one microbe is growing
What else did Koch invent?
Solid bacterial growth media, Petrie dish, stain microbes, aseptic technique.
Who set standards for hygiene in patient care and. Kept stats for all. Of it?
Florence. Nightingale
Who in vented the magic bullet and what is it?
Paul ehrlich
Kills microbes but not harm humans
How much magnification is the ocular piece?
10x
What are the two major types of microscopes?
Light and electron
What is the total mag of the light microscope?
What does immersion oil do?
What state can the bacteria be in?
100x
Increase resolution
Alive
What are the two kinds of electron microscope?
Scanning and transmission
What can you see with an SEM?
What is its max mag?
Surfaces of cells
650,000x
What can’t you see with a transmission microscope?
What is its max mag?
Internal surfaces
1,000,000x
Why do we stain?
I improve ability to see colorless microbes
What is the first step in staining?
Prepare a smear
What is a smear.
What amount of microbes?
Next step?
Thin film of microbes on a slide
PINPOINT
Air dry
What does “fixing” do?
How do we do it? (2)
Attaches microbes to the slide so they don’t rinse off, and it kills them
- use heat (we do this
- use chemicals (formalin)
What is this overall charge of most bacteria.
What charge is the stain/dye?
Negative
Positive
What is a simple stain?
What does it allow you to see?
Uses one + charged dye
Only one color
See size, shape, and arrangement of bacteria
What is a differential stain?
What do you see
What are the three examples?
Uses two + charged dyes Primary and secondary/counter stains 2 colors at the end See size, shape,arrangement, and something more Gram, acid fast, and endospore
Gram stain, what colors? After adding crystal violet what color are the bacteria? After iodine? After decolorizer? After safranin?
Purple and pink All bacteria are purple All bacteria are purple Gram + are purple, gram - are clear Gram + are purple, gram - are pink
What does adding iodine to the gram stain do?
Forms iodine crystal violet complexes that decrease solubility and get stuck under the gram positive cell walls
Why does the gram positive bacteria hold on the the crystal violet while the gram negative do not?
The crystal violet iodine complexes get stuck under the thick wall of gram positive cell walls where gram negative have thin cell walls so the deocolorizer washes it right out
What extra thing does a gram stain tell us?
Size, shape, arrangement AND whether the bacteria has a thin or a thick wall. And therefore tells us which kind of antibiotic to use
Acid fast stain, what kind of bacteria is used for?
Those with waxy walls (mycolic acid)
What are the steps of an acid fast stain?
- Prepare smear and heat fix
- Flood HOT smear with CARBOL FUSION (+)
- Wait 5 minutes and rinse
- Decolorize with acid alcohol for 2 minutes and rinse
- Flood smear with METHYLENE BLUE
- Wait 1 minute and rinse
In acid fast stain, what are the colors of the product?
What color are the baCteria after the CARBOL fusion?
After acid alcohol?
After methylene blue?
Pink and blue
All bacteria are PINK
Waxy wall pink (acid fast bacteria), no waxy wall colorless (non-acid fast)
Acid fast pink, non-acid fast blue
What does acid fast stain tell you?
What are its primary and secondary dyes, what are their charges?
Size, shape, arrangement, and if it has a waxy wall
Primary=CARBOL fusion (+)
Secondary=methylene blue (+)
What are the steps of the endospore stain?
- Prepare a smear and heat fix.
- Flood HOT smear with MALACHITE GREEN (+)
- Wait 10 minutes and rinse
- Flood smear with SAFRANIN (+)
- Wait 2 minutes and rinse
What is what color in an endospore stain?
What does an endospore stain tell you?
Red bacteria
Green endospores
See size shape color, arrangement, and learn if an endospore or bacteria
What are he the two genus that produce endospores?
Clostridium and bacillus
What kind of stain is a capsule?
What are the he steps.?
Negative stain
- Prepare a smear, DONT HEAT
- Flood smear with crystal violet (+)
- Wait 2 minutes
- rinse with copper sulfate
What is a capsule? What are they made of. Why can we not heat fix the slide? What is the charge of the capsule? Why can't you rinse with water? What colors are at the end?
A gelatinous sticky layer on the outside of bacteria, protein
We want them alive, and heating will destroy the proteins of the capsule
Neutral charge
The capsule is soluble in water
Background and bacteria are purple, the capsules are clear.
What are the different morphologies of bacteria?
What shape are they.
What two make up the majority of bacteria?
Cocci, Bacillus, and Spirals
Round cocci, rod bacillus
Cocci and bacillus
What is binary fission?
How does it work?
The process bacteria use to divide (asexually)
- Replicate DNA
- Two copies of DNA move to opposite sides of the cell
- Form a cross wall
- Separate completely or hang around together
What two questions that relate to binary fission are needed to consider when thinking of arrangement?
How many planes does it divide?
Do they separate or stay together after binary fission?
What are the 5 different arrangements of cocci?
How many planes do they divide?
How many stay together?
Dipolococci-one plane, two stay together Streptococci- one plane, long chain Tetrad- two planes, 4stay together Sarcina- 3 planes, 8 stay together Staohlococci- random planes, big clusters stay together
What are the 3 different arrangements of bacilli?
Planes and how many stay together
Diplobacilli- 1 plane, two stay together
Streptobacilli- 1plsne, long chains
Palisade- 1plane, v shape
Why do we classify? (4)
- bring order and organization to living things
- enhances communication
- allows us to make prediction ps about structures and function
- uncover some evolutionary ties/connections
What is the science of classifying and naming living organisms?
Taxonomy
What are the the 4 rules of binomial nomenclature?
- Must underline or italic entire name of microbe
- Use genus and species
- Genus first letter must’ve be capitalized
- Species first letter must be lower case
What is lenean taxonomy?
Kingdom, phylum, class, order, family, genus, species
Who invented the 5 kingdom system?
What are there 5 kingdoms?
Whittaker
Animalia, plantae, fungi, Protista, monera
Who invented the 3domain system?
He did he discover it?
What are the three domains?
Woese
By sequencing rRNA
Archae, bacteria, and eukaria
What are the 4 chareacteristics of life?
Growth, reproduction, metabolism, and responsiveness
Compare and contrast prokaryotes and eukaryotes on the board
There are 5 things
What are the cell basic and give a brief description.
4
- DNA-genetic blueprint
- Cytoplasm- open space inside cell
Cytosol- gel-like fluid tha fills cytoplasm (made of mostly water) - Ribosomes- site of protein synthesis
- Cytoplasmic/plasm membrane- boundary controls traffic in and out of cell
What is the gelatinous sticky substance that surrounds the cell wall?
What is it made of?
Where is it made?
What is the difference between a capsule and a slime layer.
Glycocalyx
Polypeptides and/or carbohydrate
Produced by the bacterium and sent to surface
Capsule, firmly attached to cell wall
Slime layer, loosely associated with cell wall
What are the functions of glycocalyx?
4
What kind of bacteria often have this?
-protect from drying out and chemicals and environmental stress
-source of nutrition
- decrease phagocytosis
- helps cling to surfaces
Pathogens
What are flagella?
Functions?
How many can they have?
How do they move?
Hair-like structure anchored to cell wall
Motility, move away or towards something
1,2, or several
By rotation, clockwise (tumble), counterclockwise (run)
What are fimbriae? How many on a bacteria? Function Example Bio films and example
Short, hair like appendages Many per bacteria Attachment STD bacteria Bacteria + debris!dental plaque
What are pili?
How do they compare to flagella and fimbriae?
How many?
Functions
Long hairlike appendage extends from the cell wall, hallow
Longer tha fimbriae, shorter than flagella
1-10 per bacteria
Bacterial sex (conjugation), grappling hook (movement)
What are the functions if a cell wall?
Who has them?
What are they made of?
Structure, shape, protection from osmotic forces
Bacteria only, animal cells have no cell wall
Peptidoglycan
What is peptide glycol made of?
Nam and nag (2 sugars) plus amino acids weaves together
Gram + cells have what thickness of cell wall?
What is it made of?
What color is it.,
Thick
Peptidoglycan and teichoic acids
Purple
What do teichoic acids do?
Anchor cell wall to underlying cell membrane
Help with overall charge of bacterium
Ion permeability through they wall
What does adding iodine to a gram stain do?
Iodine binds to crystal violet forming iodine-crystal violet complexes that get trapped I the thick layer of peptidoglycan
What does decolorizing a gram stain do to gram positive bacteria?
We dehydrate the bacteria and trap the iodine crystal violet complexes even more
What does gram negative bacteria wall consist of?
What is the outer membrane made of?
Outer membrane outside the layer of peptidoglycan
LPS- lipopolysaccharides (fat and sugar)
What symptoms does LPS cause?
Fever, inflammation, clots, shock, death
Compare gram positive and gram negative Bactria on the board
3 things
What kind two genus have waxy walls?
What are waxy walls made of and percentage
Function
What kind of stain used
Mycobacterium and nocardia 60% mycolic acid 40% peptidoglycan Protects against drying out Acid fast stain
What are inclusions and their functions
Storage of bacterium
When nutrients bit available, store in inclusions, use stored nutrients when needed
When do bacteria produce endospores? How do they work? What are they resistant to? What is sporulation, how long does it take? Germination, how kong dies it take
When bacteria is under environmental stress
The genetic copy of bacterial DNA is surrounded by super thick coat of peptidoglycan
Resistant to drying out, heat, radiation, boiling, chemicals
Sporulation- when bacteria produce endospores. 6-12 hours
Germination- when endospore is Ina good environment it will turn back into bacteria. 1.5 hours
What is microbial growth.
Increase in population size of a microbe
What is a colony.
Pure culture?
Where a single microbe divided and produced a pile of identical microbes
Energy source
Light
Organic
Inorganic
Phototroph
Heterotroph
Lithograph
Carbon source
Organic
Carbon dioxide
Heterotrophs
Autotroph
Draw table combining carbon and light sources
Look in notes
What elements make up 95% of microbe weight
The rest.?
Carbon, oxygen, nitrogen, hydrogen
Trace elements
Carbon percentage
What macromolecules use it?
50%
Carbs, protein, lipids, nucleic acids
Where do they get hydrogen?
From water
What percentage of microbes are nitrogen?
Why needed?
12-15%
To build proteins, nucleic acids, ATP
What percent of the air is oxygen and what percent carbon dioxide?
20% o2
.03% co2
Obligate anaerobes
What kind of energy production
Final member of etc
Can they ferment?
Require O2
Aerobic energy
Oxygen
Yes
Obligate anaerobes
Final member of etc
Can they ferment?
How does o2affect them
Anaerobic energy production
Nitrate or sulfate
Yes
Inhibited or killed by o2 because toxic free radicals are produced when oxygen is used,they don’t have enzymes to break Dow radicals so the py get electrons from nucleic acids and proteins and kill microbe
Microaerophile
Energy production
Can they ferment?
Like 2-10% o2
Aerobic
Yes
Facultative anaerobes
Energy production
Ferment?
Can do all three aerobic anaerobic, fermentation
Capnophile
Love co2 3-10%
How can you determine oxygen requirement of microbes?
Streak plates- provide three different atmospheres and see which ones grow (20% o2, 0% o2, and a candle jar-decrease o2 increase co2)
Thioglycollate media
What are the trace elements and where are they found?
Iron, copper, zinc-cofactors for enzymes
Phosphorous-cell membranes
Sulfur- proteins
What are minimum optimum and maximum growth temps
Minimum- lowest temp microbe can grow
Optimum- best temp for growth
Maximum- highest temp
Psychrophile
Temp?
Where found
Cold loving
Below 15 C
Refrigerator, food spoilage
Mesophile
Temp
Where found
Moderate temp loving
20-40 C
Our body!
Thermopile
Temp
Where found
Heat loving
45-80 C
Compost piles
Hyperthermophile
Temp
Example
Extreme heat loving
Over 80 C
Archae
How do you maintain good ph in media
Add buffers
Neutrophile
pH 6.5-7.5
Acidophile
<6.5
Alkinophile
7.5-11.5
What are the majority of microbes pH requirements?
Neutrophile
Can microbes tolerate acid or base better?
Acid
What is osmotic pressure?
Pressure exerted on a semipermeable membrane by a solution containing solutes that cannot freely cross the membrane.
What are the solutes of cell?
Sugar and salt
What is osmosis?
Draw hypotonic isotonic and hypertonic solutions on board
Diffusion of water from a area of high water concentration to an area of low water concentration
What is media
What are three kinds
Nutrient material suitable for the cultivation of microbes
Broth(liquid)
Solid (slant/Petri dish)
Sterile (no microbes)
Defined media
Aka
Cost
Exact chemical composition is known
Synthetic media
Very expensive, so uncommon
Complex media
Made of
Cost
What is it great for
Chemical composition varies batch to batch
Contains extracts
Inexpensive so very common
Great for unknown microbes cuz most if em love it
Selective media
Example
Encourages growth of wanted microbes and inhibits growth of unwanted microbes
Mannitol salt agar (high salt)
Differential media
Example
Makes it easier to distinguish different microbes
Blood agar
How would you preserve microbes for short term?
Long term?
Very long term?
Fridgerator
Deep freeze (-50 to -95 C)
Lyophilization- liquid culture, remove water under a vacuum until it is a powder.
Define generation time
How long does it take most bacteria
Time required for the bacteria to divide by binary fission and it varies for each species from 20 min to 10 days
1-3 days
What are hey be four stages of bacterial growth curve?
Lag phase
Log phase
Stationary phase
Death phase
What lag phase (3)
How long does it last.
No increase or decrease in number if bacteria
Bacteria are adjusting to new environment
Figuring out what nutrients are available, and make necessaryh enzymes to use these nutrients
- several hours to several days
What log phase
Increase in number of bacteria, constant binary fission, most active metabolically
What binary fission phase would someone see symptoms of disease?
Log phase
What binary phase are bacteria most susceptible to antibiotics
Log phase
Stationary phase
No increase or decrease in number of bacteria, if they grow any more they will die because they are running out of nutrients and ph is changing because of toxic by products
Death phase
Decrease in number of bacteria
Overcome by ph change and waste products and lack of nutrients
Draw and label a binary fission growth chart
Look in notes
What are the two methods for measuring microbial growth?
Direct and indirect
What are the 4 ways to directly count microbial growth.
Plate count of colonies
Membrane filtration
Grid count
Electronic counter
What are the indirect methods for measuring microbial growth?
Turbidity (cloudiness)
Dry weight
Metabolic activity
