Test 1 Flashcards
What do you think of when someone mentions microorganisms?
Human Health
How do microorganisms impact human health?
Disease can have a negative or positive impact. Probiotics are positive
What did the Human Microbiome Project state?
Humans did not evolve on their own
How do bacteria have a dominant role in our lives?
We protect them and they protect us
Are microorganisms the most populous and diverse group of organism?
Yes
Where are microorganisms found?
Everywhere on the planet
How do microorganisms benefit society?
Production of food, beverages, antibiotics, and vitamins
What does it mean when microorganisms are termed ubiquitous?
they are found everywhere, occupy 50% of the biome
How does reproduction help microorganisms become abundant?
It is a simple process and they have simple construction
What type of cells lack a membrane bound nucleus?
prokaryotic cells
What type of cells have a membrane bound nucleus?
eukaryotic cells
What is included under Cellular Organisms?
Fungi
Protists
Bacteria
Archaea
What is included under Acellular Organisms?
Viruses
Viroids
Satellites
Prions
What are viruses composed of?
Protein and nucleic acid
What are viroids composed of?
RNA
What are satellites composed of?
Nucleic acid enclosed in a protein shell
What are prions composed of?
Protein
What are the three domains that are based off of rRNA?
Bacteria
Archaea
Eukarya
What are the characteristics of Bacteria (domain)?
Single celled Cell wall w/ PGC Lack membrane bound nucleus Ubiquitous Produce oxygen
What are the characteristics of Archaea (domain)?
Unique rRNA gene sequence Lack PGC in cell wall Have unique membrane lipids Unusual metabolism Live in extreme environments
What is included under the Eukarya Domain?
Fungi
Protists
Animals
Plants
Protists characteristics?
larger than bacteria and archaea
Fungi characterists?
can be unicellular or multicellular
What is the smallest of all microorganism?
Viruses
What do viruses require in order to function?
host cell
What are infectious agents composed of RNA?
Viroids
Virusoids
What are infectious proteins?
Prions
Definition of Life includes?
Cells and organization Response to change Growth and development Evolution Energy use and metabolism Homeostasis Reproduction
How old may life on earth be?
3.5 billion years
What is the original molecule of heredity?
RNA
What is thought to have bacterial lineage through the Endosymbiotic Hypothesis?
Mitochondria and Chloroplasts through rRNA
What does hydrogenosome mean?
anaerobic lineage
What are catalytic RNA called?
Ribsomes
What is the energy currency for a cell?
ATP
How do bacteria and archaea increase their genetic pool?
horizontal gene transfer
What is another way of gene evolution?
mosaic
Why do Bacteria and Archaea not reproduce sexually?
They are strains that consists of pure cultures
What are tools used for studying microorganisms?
Microscopes
Culture techniques
Genetics
Genomics
Who was the first person to observe microorganisms correctly?
Leeuwenhoek
How did Leeuwenhoek discover them correctly?
Looked at pond water while trying to find inconsistency in his textiles
Spontaneous Generation
living organisms develop from nonliving matter
Who is responsible for the “Swan Neck Flask”?
Louis Pasteur
What did the swan neck result in?
no growth of microorganisms because he boiled the solution and left it exposed it to air
What was the final blow to spontaneous generation?
the demonstration that dust carries microorganisms (Tyndall) and that heath resistant bacteria could produce endospores (Cohn).
What did Joseph Lister do to study the relationship between microorganisms and diseases?
cleaned his surgical equipment
What did Louis Pasteur do to study the relationship between microorganisms and diseases?
Fermentation
Who was the final person to seal the study between microorganisms and diseases?
Robert Koch
What did Koch do?
developed the Koch postulate, which is used today, that established a link between microorganisms and a particular disease.
What did Koch’s discovery to to the development of?
Agar
Petri dishes
Nutrient broth and agar
Isolation of microorganisms
What two people discovered that incubation for a period of time can kill a disease?
Pasteur and Roux
Who developed vaccines?
Pasteur
Who created the vaccine for smallpox?
Jenner
Who found evidence for antibody based immunity?
Behring and Kitasato, through antitoxins
Who discovered phagocytes?
Metchnikoff
The root or origin of modern life is on a bacterial branch but nature still controversial
xx
What is the largest microorganism?
protists and bacteria
What is the range for the sizes in microscopy?
Largest to smallest: Cm mm um nm A
How does light pass from one medium to another?
it is refracted (bent)
What is the refractive index?
Measure of how greatly the velocity of light is slowed down
What is the focus of light rays at a certain point called?
Focal point
What is the distance between the lens and the focal point?
focal length
What type of lens is stronger?
shorter, the shorter the focal length the stronger the magnification
What are the different types of light microscopes?
Bright Field Dark Field Phase Contrast Fluorescence Confocal
What is the microscope we use?
the bright field
What type of image does a bright field produce?
Dark image against a bright background
What is total magnification?
product of magnifications for the ocular lenses and objective lenses
What is the working distance?
distance between front surface of lens and surface of slide.
Describe the Oil Immersion Objective?
Oil replaces air allowing for ray that could not enter to now do so to enhance the resolution of the image.
What is the dark field used to study?
living, unstained organisms
What type of image does the dark field produce?
bright image against a dark background
What does the phase contrast microscope do?
converts refractive index differences into variations of light intensity
What does the DIC do?
determines differences in refractive index and thickness of the specimen parts
What does the fluorescence microscope do to a specimen?
Exposes them to UV, Violet, or blue light
What are the specimens under a fluorescent microscope stained with?
fluorochromes
Why is the fluorescent microscope essential to microbiology?
it tags specific cell structures by using dyes and fluorochrome probes to identify pathogens. Also localizes specific proteins in cells
What microscope creates a 3D image?
Confocal Microscope
What increases visibility of a specimen?
Staining
What method preserves internal and external structures and fixes them into position?
fixation
What are the two types of fixation?
Heat and Chemical
What is heat fixation?
used for bacteria and archaea; preserves overall morphology
What is chemical fixation?
used with larger organisms; protects fine structures
What do dyes do when used for staining?
Make internal and external structures more visible to contrast with the background
What charge do basic dyes have?
positive
What charge to acid dyes have?
negative
What is a simple stained used for?
a single stain to determine shape, size and arrangement of bacteria
What does a differential stain do?
divides microorganisms into groups based off of the stains
Examples of differential stains?
gram stain
acid fast stain
What structures are differential stains used to detect?
endospores, flagella, and capsules
Describe the process of gram staining?
- Crystal violet (primary stain) for one minute; rinse
- Iodine (mordant) for one minute; rinse
- Alcohol (decolorizer) for 10-30 seconds; rinse
- Safranin (counterstain) for 30-60 seconds; rinse; dry
What is a gram positive stain?
cell remains purple
What is a gram negative stain?
cell became colorless then pink/red after the safranin (secondary stain)
What genus is acid fast staining used for?
Mycobacterium
What does the acid fast staining stain?
the cell wall high lipid content
What structure staining involves double sating technique where the endospore is one color and the vegetative cell is another?
Endospore staining
Which type of structure stain is used to identify the polysaccharide capsules surrounding bacteria?
Capsule staining
What is applied to increase the thickness of a flagella when doing the structure stain?
mordant
What replaces light in the electron microscope?
Electrons
How do electrons work in the TEM?
they would usually scatter, but the TEM holds them in a vacuum to produce a clear image
What is a type of metal stain used for studying viruses?
negative staining
What type of metal staining is useful for viral morphology, flagella, and DNA?
shadowing
What is another stain that does not use metals?
Freeze etching
What microscope produces a realistic 3D image?
Scanning electron microscope
What is a rapid freezing technique to preserve native state of structures?
electron crytomography
How do prokaryotes differ from eukaryotes?
Lack internal memb. systems, size, and simplicity
What shape can bacteria and archaea have?
cocci and rods are most common
How is the arrangement determined in bacteria and archaea?
by plane of division and if they separate or not
What are the shape of cocci?
Sphere
Structure of diplococci?
in pairs
Structure of steptococci?
chains
Structure of staphylococci?
grape like
Structure of tetrads?
4 cocci in a square
Structure of sarcinae?
cube of 8 cocci
What shape do bacilli have?
rods
What shape do vibrios resemble?
rod ( , shape)
What shape do spirilla have?
rigid helices
What are spirochetes?
flexible helices
What does mycelium look like?
network of long filaments
What is important for nutrient uptake dealing with size and shape?
surface to volume ratio
What are common features for bacteria?
cell envelope
cytopolasm
external structures
What does the bacterial cell envelop consist of?
Plasma membrane
Cell Wall
Layers outside the cell wall
What are plasma membrane functions?
encompasses cytoplasm
selective permeable
interacts with the environment
How does the plasma membrane interact with external environment?
receptors for detection of chemicals
transport systems
metabolic processes
Describe the fluid mosaic model structure of the plasma membrane.
lipid bilayer with floating proteins (amphipathic lipids, membrane proteins)
What are the amphipathic lipids of the fluid mosaic model?
polar (hydrophilic) and non polar (hydrophobic) tails
What are the membrane proteins of the fluid mosaic model?
peripheral (loosely connected)
integral (amphipathic embedded within the membrane)
What does amphipathic mean?
having both hydrophobic and hydrophilic ends
What do saturation levels of membrane lipids reflect?
environmental conditions
How do sterols help membranes?
stabilize membranes
What are the macronutrients?
C, O, H, N, S, P, K, Ca, Mg, and Fe
Which of the macronutrients are found in organic molecules?
C, O, H, N, S, P
Which of the macronutrients are cation?
K, Ca, Mg, and Fe
What do cations do primarily?
assist enzymes and biosynthesis
What are the micronutrients?
Mn, Zn, Co, Mo, Ni, and Cu
How are micronutrients supplied?
through water and media components
Micronutrients do not assist enzymes?
False they are cofactors
What classes help growth factors?
amino acids
purines and pyrimidines
vitamins
What are amino acids needed for?
protein synthesis
What are purines and pyrimidines needed for?
nucleic acid synthesis
What are vitamins need for?
enzyme cofactors
What are the methods for nutrient uptake?
passive diffusion
facilitated diffusion
active transport
group translocation
What is passive diffusion?
molecules move from HIGHER to LOWER concentration; energy dependent
What is facilitated diffusion?
movement of molecules from HIGHER to LOWER concentration; not energy dependent
What impacts the rate of uptake in facilitated diffusion?
size of gradient; smaller is most significant
What is active transport dependent on?
ATP or proton force
What are permeases?
carrier proteins
How does active transport move molecules?
against the gradient
What are the primary transporters in active transport?
ABC Transporters
What do ABC Transporters consist of?
a hydrophobic membrane, ATP binding sites, and substrate bindings
What do secondary active transport systems use?
ion gradients
Two substances both move in the same direction
symport
Two substance move in opposite directions
antiport
What system chemically modifies molecules as they are brought into the cell?
Group translocation
What is the bacterial cell wall mad up of?
peptidoglycan
What is peptidoglycan?
rigid structure lying outside the plasma membrane
What are the function of the cell wall?
maintain shape
protect
contribute to pathogenicity
What are the results of the gram stain on the peptidoglycan layer?
Positive; thick
Negative; thin
What are the alternating amino acids in the peptidoglycan layer?
D and L
How are peptidoglycan strands shaped?
cross linked by peptides
What are type of amino acids are found in proteins?
L amino acids
Why are there D amino acids in the bacterial cell wall?
to help against degradation
What acid helps maintain the cell envelope, protect, and help bind to host cells?
teichoic
Where is the periplasmic space of a G+ bacteria?
between the cell wall and the plasma membrane
What do the exoenzymes in the periplasmic space help in?
degradation of large nutrients
What is the structure of a G- bacteria?
outer membrane
thin peptidoglycan layer
plasma membrane
What lipoproteins connect the OM to the peptidoglycan in G- cell walls?
Braun’s lipoproteins
What are the three parts to the lipopolysaccharide?
lipid A
core polysaccharide
O side chain
What is the importance of LPS?
(-) on cell surface
stabilize OM
attach to surfaces
What does lipid A do for the LPS?
acts as an endotoxin
What does O do for the LPS?
hosts defense
What allows G- to be more permeable than G+?
porin and transporter proteins
What do G+ cells do when CV hits it?
pores shrink trapping the CV
What do G- do when CV hits?
nothing
How does osmotic protection help in hypotonic environments?
prevents cell wall fro lysis
How does osmotic protection help in hypertonic environments?
doesn’t; lysis occurs
What cells can survive in isotonic environments without a cell wall?
protoplasts
spheroplasts
mycoplasma
Glycocalyx is …?
outermost layer in cell envelope
What do glycocalyx do?
aid in attachment
What do the components outside the cell wall do?
protect from phagocytosis and desiccation
What does the S layer function in?
protection
maintaining of shape
promotes adhesion
What are the structures in the cytoplasm?
Cytoskeleton Intracytoplasmic membranes Inclusion Ribosomes Nucleoid and Plasmids
What is the protoplast?
plasma membrane and everything within
What is the cytoplasm?
material bounded by the plasmid membrane
FtsZ cytoskeleton look like?
rings
MreB cytoskeleton look like?
rods
CreS cytoskeleton look like?
curve shape (rare)
What are plasma membrane infoldings?
intracytoplasmic membranes
What are inclusions?
granules of organic or inorgranic material that are stored for future use
What do inclusions store?
glycogen, carbon, phosphate, and amino acids
Are micro compartments bound by membranes?
no
What do gas vacuoles do and where are they found?
provide buoyancy in gas vesicles and found in aquatic bacteria and archaea
What is the sire for protein synthesis?
ribosome
70S is in what?
bacteria and archaea ribosomes
80S is in what?
eukaryotic ribosomes
The nucleoid is what for the bacteria?
one enclosed circular double stranded DNA molecule
What is a plasmid?
closed circular DNA molecule found in bacteria, archaea, and some fungi
How do plasmids replicate?
independently
What are external structures of the cell?
pili and flagella and fimbriae
What are short hairlike, protein appendages?
fimbriae
What are longer, thick, hair like structures?
Sex pili
What is flagella?
locomotive appendages, help attach to surfaces
Monotrichous flagella?
one flagellum
Polar flagellum?
flagellum at the end of cell
Amphitrichous flagella?
one flagellum at each end of cell
Lophotrichous flagella?
cluster of flagella at both ends
Peritrichous flagella?
spread over all surface
What powers a bacterial flagella?
basal body of rings
What secretion system is used for flagellar synthesis?
Type III
What are the different types of motility?
flagellar swarming spirochete twtich glide
how do bacterial flagellar move?
propeller movement
What are the two parts to the flagella motor?
Rotor and Stator
What are chemotaxis?
movement towards a chemical attractant or away from a chemical repellent
What is the endospore?
dormant structure formed by some bacteria that also protects from environmental conditions
What type of coat does the endospore have?
protein
What is in the core of the endospore?
nucleoid and ribsomes
