Microbiology Midterm Flashcards
Microbiology
The study of microorganisms and their effects on other organisms
What is the difference between eukaryotic and prokaryotic organisms
Eukaryotic organisms have a nucleus. Prokaryotic organisms do not have a nucleus (nucleoid region instead)
Toxonomic Hierarchy
1) Domain 2) Kingdom 3) Phylum 3)Class 4) Order 5) Family 6) Genus 7) Species
3 Primary Domains
Bacteria, Archea, Eykarya
The Five Kingdoms
1) Monera - prokaryotes
2) Protista - eukaryotes
3) Fungi - eukaryotic, spore-producing
3) Plant - photosynthetic eukaryotes
4) Animal - complex multicellular, eukaryotic organisms
Binomial Nomenclature
Microorganisms have two names and are named based on their characteristics. The first name is the Genus and the second name is its species
Bacteriology
Study of bacteria
Mycology
Study of fungi
Protozoology
Study of Protozoa
Rickettsiology
Study of Rickettsia
Immunology
Study of the immune system
Characteristics of Bacterial Cells
1) prokaryotic
2) Single Celled
3) Multiply with Binary Fission
Basic Characteristics of Mycoplasma Bacteria
1) No cell wall
2) Smallest free-living organism
Basic Characteristics of Rickettsia Bacteria
1) Gram-negative
2) Intracellular (Lives inside other cell wall)
3) Spread by lice, fleas, ticks, and mites
Basic Characteristics of Chlamydia Bacteria
1) Nonmotile
2) Intracellular
3) Gram-Negative
Basic Characteristics of Protozoa
1) Eukaryotes
2) Single Celled
3) Simplest form of animals
Basic Characteristics of Fungal Organisms
1) eukaryotic,
2) non-vascular,
3) non-motile
4) heterotrophic
Basic Characteristics of a Virus
1) Microscope needed to see it
2) DNA or RNA
3) Intracellular
Basic Characteristics of a Prion
1) Protein
2) Highly resistant
3) Infectous
4) Alters other cells’ nucleus acids
Father of Microbiology
Anton Van Leeuwenhoek
(observed microorganisms in water and other substances; first to observe red blood cells)
Compound Light Microscope
Used to identify bacteria
Electron Microscope
Used to identify viruses (due to their submicroscopic size)
Gram Staining Technique Reactions
1) Gram-Positive - cell wall is thick; purple when stained; killed by penicillin
2) Gram-Negative - (cell wall is thin; pink when stained’ penicillin-resistant
Differential Staining Techniques
1) Gram Staining
2) Acid-Fast Staining
Acid Fast Staining Technique Reaction
Cell-wall is very fatty
Not decolorized easily by acids after staining
Morphology
Study of shape ad form (without regard to function)
What is the unit of measure used to report the size of bacteria cells
Micrometers (um)
3 Primary Shapes of Bacterial Cells
1) Spherical
2) Rod-shaped
3) Spiral
Draw and describe a coccus bacterial cell
1)Spherical
2) causes strep, skin abcesses
Describe & draw a bacillus bacterial shell
1) Rod-shaped
2) Cause tetanus, anthrax
Describe & draw a 1) Vibrio, 2) spirochete, & 3) spirillum bacterial shell
1) Comma-shaped, gram negative
2)Helical (spiral), Rigid when in motion
3) Helical (spiral), Flexible when in motion
Describe monomorphic vs pleomorphic bacterial cells, & which term best describes the majority of bacterial cells
1) monomorphic – Don’t change shape MOST CELLS
2) Pleomorphic – Change shape
Diplococci
Cocci= remains in pairs after dividing
Streptococci
- spherical,chain arrangement
-found in blood poisoning and strep throat
Tetrads
Divide in 2 planes, remain in groups of 4
Sarcinae
Spherical, divide in 3 planes, remain attached in cube-like groups of 8
Staphylococci
Cocci, divide in multiple planes, form grape-like clusters
Diplobacilli
Rod-shaped, divide across their short axis, remain in pairs after cell division
Streptobacilli
Bacilli, divide across short axis, remain in chains
Coccobacilli
Rod-shaped, oval, look like cocci (so called “coccobacilli”)
Describe structures that some bacteria can produce external to the bacterial cell wall
1) Capsule/Glycocalyx
2) Flagella
3) Axial Filaments
4) Pili/Fimbriae
Capsule/Glycocalyx
Sticky gelatinous coating, surrounds cell wall
- Resists phagocytosis (Too slimy to “eat”)
- example: Streptococcus pneumoniae (pneumonia)
Flagella
Long whiplike filament that provides movement
Types of Flagella
- Monotrichous – 1 flagellum
- Amphitrichous – 1 flagellum at both ends
- Lophotrichous – Bunch of flagella at 1 end
- Peritrichous – Entire surface covered in flagella
Taxis
The movement of a bacterium toward/away from stimulus/environment
Types of Taxis
1) Phototaxis: Stimulus= light
2) Chemotaxis: Stimulus= Chemicals
Axial Filaments/ Endoflagella
Unique flagella –(Like ridges on licorice wand); They move in a corkscrew motion
What bacterium has axial filaments/ endoflagella?
Spirochetes (spiral-shaped)
example: Treponema pallidum (syphilis)
Pili/ Fimbriae
Grabs things (“attachment”)
Example: Neisseria gonorrhoeae (gonorrhea)
Describe important characteristics of the bacterial cell wall
1) Prevents bacteria from rupturing
2) maintains shape
3) point of anchorage for flagella
4) can cause disease (in humans)
5) site of action for antibiotics
6) Made of Peptoglycan (“chain-link fence” look)
7) Chemical composition can be used to differentiate types
Describe characteristics of the Gram-positive cell wall
Purple (when stained), thick cell wall
Describe characteristics of the Gram-negative cell wall
Pink (when stained), thin cell wall
Identify a digestive enzyme that can cause damage to the bacterial cell wall
Lysozyme
Protoplast
Cell whose cell wall was removed
Spheroplast
What remains of a cell/its cell wall after being partly destroyed
[ex: by lysozyme]
Describe the plasma membrane of a bacterial cell
1) Inside the cell wall
2) function: determine what substances enter/exit the cell
3) breaks down nutrients
3) produces ATP (energy)
Describe the difference between a 1) passive and 2) active transport mechanism
1) Substance passes from area of high concentration to low concentration (no energy needed)
2) Substance passes from area of low concentration to high concentration (energy needed)
Different Types of Transport Mechanisms
a. Simple diffusion - for small molecules
b. Facilitated diffusion - Needs a carrier protein to help it cross, but still NO energy required (“gets a ride”)
c. Osmosis - Only for water
Describe what may happen to a bacterial cell in an isotonic solution
Equilibrium (solute outside cell= same concentration as inside)
Describe what may happen to a bacterial cell in a Hypertonic solution
Will explode (solute outside cell= higher than inside cell)
Describe what may happen to a bacterial cell in a Hypotonic solution
Will implode (solute outside cell= lower than inside cell)
Active transport
Uses transporter proteins
Substance being transported is NOT chemically altered during transport
Group translocation
Used by prokaryotic cells
Substance being transported is chemically altered during transport
Describe the location of the cytoplasm for a prokaryotic cell
Inside plasma membrane – basically the whole inside of the cell (they’re basically the same thing)
Describe the location of the cytoplasm for a eukaryotic cell
Everything around nucleus (inside plasma membrane)
Describe the nuclear body
Protects/surrounds the nucleus
Other names: “Nuclear region,” “nucleoid”
Describe the primary function of a bacterial ribosome
Create proteins (protein synthesis)
Describe the function of bacterial inclusion bodies
“Temporary storage containers” – (Like when a squirrel stores nuts away for use in the winter when he needs them)
What is the shape of an endospore?
Rod-shaped
What is the Genera of an endospore
1)Clostridium
2) Bacillus
What environmental conditions may cause endospore formation
1) Boiling
2) drying
3) radiation
Other names for the process of endospore formation
1) “Sporulation,”
2) “sporogenesis”
Another name for the non-spore state of the endospore-forming bacterium
Vegetative
The process of an endospore returning to a vegetative state
Germination
Describe endospore formation as either a reproductive or protective mechanism
Protective
