Microbiology Exam 1
Microscopy that uses light
-bright field -dark field -phase contrast -epifluorescence -confocal
Eukarya
-can be single or multicellular -HAS nucleus -NO peptidoglycan -found in nonextreme environments -NOT prokaryotic in structure
Three most important energy-conserving cellular organelles
-chloroplasts -mitochondria -hydrogenosomes
Peptidoglycan
-contains D-amino acids not found in proteins -polymer of alternating N-acetylglucosamine (NAG) and N-acetykmuramic acid (NAM)
endospore
-core has high amounts of dipicolinic acid complexed with calcium ions -core has a slightly acidic pH -core has low water content
slime layer
-easily removed -diffuse (unorganized) -facilitate motility
algae
-eukaryotic -single cell or multicellular members -all members are photosynthetic -members have a cell wall
fungi
-eukaryotic -single cell or multicellular members -members are NOT photosynthetic -members have a cell wall
protozoa
-eukaryotic -unicellular members -SOME members are photosynthetic -members DO NOT have a cell wall
Plastids
-found in photosynthetic protists and plants -often contain pigments -can be a site of synthesis and storage of food reserves -chloroplasts are one type of plastid
functions of actin filaments
-moving structures within the cell -cytokinesis -endocytosis -amoeboid movement
gram negative
-pink -thin peptidoglycan -teichoic acids absent -outer membrane present -LPS present -less sensitive to penicillin -not sensitive to lysozyme
gram positive
-purple -thick peptidoglycan -teichoic acids present -outer membrane absent -more sensitive to penicillin -sensitive to lysozyme
microscopy that does not use light
-scanning electron -cryotomography -scanning tunneling -atomic force
Bacteria
-usually single-celled -NO nucleus -HAS peptidoglycan -found in all environments -prokaryotic in structure
Archea
-usually single-celled -NO nucleus -NO peptidoglycan -found in all environments -prokaryotic in structure
capsule
-well organized -not easily removed -helps resist phagocytosis
Koch's Postulates
1. The microorganism must be present in every case of the disease but absent from healthy organisms. 2. The suspected microorganisms must be isolated and grown in a pure culture. 3. The same disease must result when the isolated microorganism is inoculated into a healthy host. 4. The same microorganisms must be isolated again from the diseased host.
Defective proteins
1. Ubiquitin is attached to defective protein 2. The tagged protein is recognized by the proteasome 3. The defective protein is cleaved into smaller peptides 4. Ubiquitin is released and recyled
strain
A common definition is that bacterial and archaeal species are a collection
endospore
A dormant cell state
When observing flagella distribution patterns, bacteria with a single flagellum at each pole are called ________________ bacteria.
Amphitrichous
viroid
An infectious agent consisting of only RNA
prion
An infectious agent consisting of only protein
virus
An infectious agent made up of protein, nucleic acids and sometimes a lipid membrane
gas vesicle
Contains compounds that aid in buoyancy
chromosome
Contains genetic information required for survival
storage granules
Contains high-molecular weight polymers
plasmid
Extrachromosomal DNA molecules
Which of the following advances best describes that today we may be experiencing a second golden age of microbiology?
Genomic Testing
cytoskeleton
Involved in cell division and controlling cell shape
Examine the following genetic sequences and determine which pair are the most similar based on their ED (evolutionary distances). Species 1 = ATTGGCCATT Species 2 = ATTCCGGTTT Species 3 = TTTGGCCATT Species 4 = ATTCCCCCCC
Most similar are: Species 1 = ATTGGCCATT Species 3 = TTTGGCCATT
When analyzing the outer membrane of Gram-negative bacteria, which part of lipopolysaccharide induces an antibody response?
O antigen
To determine the relatedness of a new species of microbe to other species, genes that encode small subunit ____ molecules are compared to determine the number of differences in the sequence.
RNA
medical microbiology
The study of diseases in humans and animals is the field of _____________
in eukaryotic cells, the thinnest cytoskeletal filaments are composed of ______
actin
Merging both medical and microbial ecology, the field of ___________ microbiology concerns the role of microbes in crop production and as pesticides.
agricultural
biovars
biochemical or physiological differences
lipid rafts
contain lipids and proteins
proteasome
degrade misfiled proteins
Fredrick Griffith
describes bacterial transformation
John Snow
determined the source of the cholera outbreak
morphovars
differ morphologically
Louis Pasteur
disproves spontaneous generation with swan neck flasks
serovars
distinctive properties that can be detected by antibodies
Clostridium botulinum, which produces a toxin that causes botulism, is a major concern of the food industry due to its production of an extremely heat-resistant ________.
endospore
The three domain system, comprising the bacteria, the _________, and the archaea, was devised in the 1970s by Carl Woese.
eukarya
Which of the following microscopes typically uses dyes or antibodies?
fluorescence microscope
Another area that parallels agricultural microbiology is the study of microbial spoilage, which is part of the field of __________ microbiology.
food and dairy
Capsules and slime layers are networks of polysaccharides that can extend from the bacterial surface. Both capsules and slime layers can be encompassed by the general term _________________.
glycocalyx
Scientists study how the immune system protects the body in the field of
immunology
Researchers in the field of __________ microbiology develop ways to exploit the metabolic abilities of microbes to generate valuable products.
industrial
Atovaquone
inhibits the electron transport system in protozoans and thereby, limits the microbes abilities to have chemical reactions.
ribosome
involved in protein synthesis
The first direct evidence of primitive cellular life was the 1977 discovery of _________ fossils in the Swartkoppie chert, a type of granular sedimentary rock rich in silica.
microbial
In the field of _________, however, a variety of approaches are used to describe microbial diversity in terms of relationships between organisms and their environments.
microbial ecology
A(n) ________ microscope keeps an object in focus when the objective lens is changed.
parfocal
pathovars
pathogenic strains distinguished by the plants in which they cause disease
The bacteria flagellum is driven to rotate by protons moving down a charge and pH gradient and the energy provided is called the _________ ___________ ____________.
proton motive force
Epidemiologists working in the field of __________ microbiology monitor the prevalence of disease in populations.
public health
Carl Woese distinguished between the members of the Archaea and the Bacteria using studies of their
ribosomal RNA
What microscope would be the best to use to view cell surface features of a specimen?
scanning electron
Which microscope is the best for viewing the DNA double helix?
scanning tunneling
inside eukaryotic cells, the ________ pathway functions to move cellular material to various locations within the cell, as well as to the plasma membrane or cell exterior
secretory
A lens with a _____ focal length should have a greater magnification.
short
Many bacteria have overcome the difficulty of iron uptake by secreting low-molecular, weight iron-binding proteins called _________.
siderophores
When light generated by a lamp in a light microscope passes into a lens, the speed of the light _______ because the glass lens has a _______ refractive index than the air from which the light came.
slows; greater
Edward Jenner
smallpox vaccine
What would be the best technique to prepare and view the internal structures of fungal hyphae?
transmission electron
Which microscope would be the best to use to constituents within a cell?
transmission electron
penicillin
will bind to a microbial enzyme that synthesizes the bacterial cell wall.
Streptomycin
will bind to ribosomes and interfere with proper protein synthesis.
Acyclovir
will inhibit the process of viral genome replication.
Rifamycin
will prevent transcription machinery from producing mRNA.