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173 Cards in this Set
- Front
- Back
Microbiology: its major groups
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bacteria, viruses, protozoa, algae, helminths
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Microbiological endeaveors
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Immunology, public health& epidemiology, food/dairy/aquatic microbiology, biotechnology, genetic engineering/ recombinant DNA tech, astromicrobiology/martian microbes
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Viruses
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- simper than cells
- contains a small amount of hereditary material wrapped up in a protein covering |
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Microbial Dimensions-
Visible |
louse,reproductive structure of bread mold
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Microbial Dimensions-
light microscope |
colonial alga
red blood cell, white blood cell, amoeba most bacteria Rickettsia bacteria, Ro-shaped bacteria, Coccus-shaped bacteria |
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Microbial Dimensions-
electron microscope |
mycoplasma bacteria, pxvirus
AIDS poliovirus, Hepatitis B virus Flagellum, large protein, DNA dimater |
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Microbial Dimensions-
special microscopes |
amino acid
Hydrogene atom |
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Leeuwenhoek
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constructed more than 250 small microscopes (300X)
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Hypothesis will be invalid if experiments dont support it?
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not necessarily; it just means the hyothesis needs to be reevaluated with further tests
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Experiments support a hypothesis. This then becomes a theory?
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not right away; more experiments shall be tested by others as well.
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A theory is the result of a single experiment repeated over ad over again
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No. It is not jut one single experiment but "an entire body of ideas that expresses or exlains many aspects of a phenomenon"
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Law, the next level of confidency to theory, is always true
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No, with the advance of technology, the past laws can be found as false.
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Discovery of microbes everywhere
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People developed medicies for them
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John Tyndall
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found that some microbes are very resistant to heat
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Ferdinand Cohn
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bacterial endospores: heat resistant
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Robert Koch
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-microscopic organisms--> specific diseases
-supported germ theory with Koch' postulates (whether an org is pathogenic and which disease it cuases) -found bacteria for anthrax -provided basic premise for pathogen-disease link |
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Dr. Oliver Wendell Holmes
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babies born at home experienced fewer infections than those at hospitals
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Dr. Ignaz Semmelweis
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Babies get infected from physicians who came ffrom autopsy room
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Joseph Lister
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introduced aseptic techniques to prevent infections: washing hands, sterilization
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Louis Pasteur
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- pasteurization
- infection proved to cause diseases ----> gave foundation for the germ theory of disease |
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Classification
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organizing organisms that indicate evolutionary relationships and history
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Nomenclature
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"process"of assigning names to various taxonomic rankings of each microbial species
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Identification
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process of determining and recording the traits of organisms to enable their placement in an overall taxonomic scheme
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Three domains (Woese-Fox system)
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prokarya, eukarya, archea
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Scientific name
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binomial system of nomenclature
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Evolution is supported by study of
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morphology
physiology genetics |
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Evolution's two preconceptions
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all new species are from preexisting species
closely related org evolved from comon ancestral forms |
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All species that are present have evolved together to be called the "advanced" in comparison to the "primitive"
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No. They did not evolve at the same time; some arose earlier than others
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5 Kingdoms
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plants
animals protists bacteria (monera) fungi |
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Virus is in the kingdom of Monera
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NO virus is not included in any becuase it is not a cell.
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cells have..
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a figure,cytoplasm, cell membrane, ribosome, DNA
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Organelles of Eukaryotic cells
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do specific activities for metabolism, nutrition, synthesis...
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living beings..
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1.reproduction
2. growth 3. metabolism, cell synthesis, release energy 4. move/ irritability 5. cell support 6. transport things into/ out of the cell |
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eukaryotic cells mostly engage in ___ for cell division when prokaryotic cells do by ____
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mitosis, bnary fission
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prokaryotes have ribosomes
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that are smaller than those of eukaryotes. Scattered throughout the cytoplasm
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photosynthesis occurs
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in chloroplasts (eukaryotic)
in specialized areas of cell membrane (prokaryotic) |
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Engergy is generated
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in mitochondria (eukaryotic)
by cell membrane (prokaryotic) |
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All cells experience true mobility?
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No
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Movement of cells
- locomotor organelles of eukaryotic cells |
cilia, flagella, pseudopods
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Movement of cells
of prokaryotes |
unique flagella of special fibrils for gliding (no cilia or pseudopods)
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All cells experience irritability
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Yes
-> diversity, adaptation |
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Transport of materials is similar in both eukaryotic and prokaryotic cells
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Yes: tow directional transport
Golgi apparatus in eukaryotic does specialized job-sorting and packaging |
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Bacteria is a category of prokaryotes with ___ in their cell walls
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peptidoglycan
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Appendages of bacteria :____. _____
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flagella and axial filamens(motility): fimbriae and pili (ttachment or channels)
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Flagella has three components...
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1. filament (with flagellin protein)
2. Hook (surrounds filament) 3. Basal body (anchored to cell membrane through cell wall) |
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flagellated bacteria
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all spirilla
half of bacilli some of cocci |
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flagellaged in two patterns
1) 2) |
1)polar arrangement - one or two ends of the cell ; monotrichous, lophotrichous, amphitrichous
2) peritrichous - dispersed randomly over the surface of the cell |
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__pathogens cause majority of illnesses, hospitalizations, and deaths
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8
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1/ ___ of americans get sick each year
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1/6
*3000 die from foodborne diseases |
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Top five pathogens causing domestically acquired foodborne illnesses
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Norovirus
Salmonella, nontyphoida clastridium perfringens Campylobacter spp Staphylococcus aureus |
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Top five pathogens causing domestically acquired foodborne illnesses "resulting in hospitalization"
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Salmonella, nontyphoical
Norovirus Campylobacer spp. Toxoplasma gondii E. Coli |
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Top five pathogens causing domestically acquired foodborne illnesses "resulting in death"
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salmonella
toxoplasma gondii Listeria monocytogenes Norovirus Campylobacter spp |
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Harms of Microbes overtime
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-People getting more susceptible as aging
- Population as become more mobile - Emerging new diseases - Resistance to drugs - Association roles of microbes in genetics/ lifestyle diseases |
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West Nile Fever
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- found in Africa, Asia, Middle East
- 1% of US=> West Nile encephaitis |
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Arbovirus
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- isolated in 200 bird species, dogs, cats, rodents, horses, alligators
- test sentinels routinely for evdence of infection |
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Benefits of studying medical microbiology
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1. emerging diseases control
2. Population mobility 3. Advances in medicine |
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6 Types of Microorganisms:
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bacteria
viruses Fungi Protozoa (protists) Algae (protists) Helminths (worms) |
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Eucaryotic cells are of:
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animals, plants, fungi and protists
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Procaryotic cells are of
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bacteria and archaea
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monotrichous &lophotrichous; amphitrichous & peritrichous
These are two patterns of flagella arrangement |
NO. peritrichous is on its own. other three are of a polar arrangement.
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To see arrangement of flagella...
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- special stain
- electron microscope - stab a tiny mass |
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Positive chemotaxis: moving towards the favorable chemical stimulus, a repellent
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No.
It shows a negative chemotaxis from a repellent. |
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What sets the signals to the flagellum to move?
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Receptors bound to specific molecules in the cell membrane
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Flagella ___ when rotating counterclockwise; ___ when rotating clockwise
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run, tumbles
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Bacteria makes sure to run straightly towards the stimulus
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No. Runs are interrupted by several tumbles to change the direction.
The runs will increase as nearing the stimulus. |
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Periplasmic Flagella is located in ____
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the space between the outer sheath and the cell wall peptidoglycan
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Periplasmic flagella can be found in ___ bacteria
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spirochetes
-> unusual "wriggly mode of locomotion caused by two or more long coiled threads:" |
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How does periplasmic flagella move?
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It contracts and imparts-> twisting or flexing motion
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Fimbriae are _____ from the surface of many bacterial cells.
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small bristlelike fibers
->function: adhesion -> leading to biofilms and other aggregaes of cells on liquids or inanimate solids |
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The composition of fimbriae varies.
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Yes. But most of them have protein.
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Pilus is an elongate rigid tubular structure made of a special protein ____
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Pilin
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All bacteria have pilus for conjugation
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NO. only those gram negative cells.
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Those prodution of pili is controlled
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genetically
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Gram positive cells do conjugation
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through aggregation proteins rather than pili
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Glycocalys is the coating of macromolecules to ...
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1. protect cells from dehydration/ nutrient loss
2. inhibit killing by WBC by phagocytosis 3. attachment |
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Glycocalyx is located in ___,
made of ____ and ___ |
external to the cell wall
sugars proteins |
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Bacteria differ glycocalyces in
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thickness, organization, chemical composition
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Two types of glycocalyx
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1. slime layer
2. capsule: more tightly attached, thicker gummy sticky mucoid character |
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Capsules are formed by many ___ic acteria
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pathogenic;
it protects them against WBC |
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Some bacteria has highly adherent glycocalyx
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to colonize on plastic catheters, metal pacemakers. ...
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Outside of the cytoplasm is called ____ where has a chemically complex external covering
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cell envelope
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Cell envelope is composed of two layers:
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cell wall and cell membrane
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Physical difference of gram + and - bacteria
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+: two layers= hick cell wall mostly of peptidoglycan and cell membrane
-: three layers= outer membrane, thin peptidoglycan, cell membrane |
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Gram positive bacteria has thick cell membrane unlike gram netative bacteria
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No. It has thick cell WALL (which absorbs the stain) , thin cell membrane.
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Structure of cell walls does..
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1. determine cell shape
2. prevents lysis or collapsing from osmotic pressure |
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Peptidoglycan is a unique macromolecule composed of a repeating framework of _________.
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long glycan chains cross-linked by short peptide fragments (negatively charged.)
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Gram positive cell wall contains...
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acidic polysaccharides, peptidoglycan, lipoteichoic acid, teichoic acid (directly attached to peptidoglycan)
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Teichoic acid and lipoteichoic acid are both attached to the plasma membrane.
Their functions are ___. |
-No teichoic acid is embedded in "peptidoglycan sheath" while lipoteichoic acid is attached to the "lipids in plasma membrane"
- cell wall maintenance and enlargement during cell division |
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Gram positive cell membrane has big periplasmic space
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No. Its really tight mostly.
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How does gram positive cell wall stimulae a specific immunes response?
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it moves cations across the cell envelope
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Teichoic cids of S. aureus atract
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host secretory gllA phospholipase A2up to 1000X during cute inflmmation
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gram negative cell wall is similar to those of cell membrane
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Yes. And it contains lipopolysaccharides and lipoproteins.
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Gram negative cell wall also has lipoteichoic acid.
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No.
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Gram negative cell
-outer most:____ with ___ embedded |
polysaccaharidesstrands, lipids
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The lipid portion of gram negative
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become toxic when released during infection ENDOTOXIN
- polysaccharides function as receptors to block immune response |
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____ of gram negative cell wall hin the upper layer of the OM have some regulatory control over molecules entering and leaving the cell.
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Porins
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Bottom layer of the outer membrane has
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similar structure to the cell membrane: phospholipids and lipoprotein.
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Becuase of the rigid structure and thick cell wall layers of gram negative cell wall, lysis rarely occurs.
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No. It is three layers yet each layer is thin so has a relatively greater flexibility ad sensitivity.
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Periplasmic space is the place
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where substances enter and exit the cell
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Because of the thick peptidoglycan layer in gram positive, it is harder to kill gram positive cells.
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NO. It is harder to kill gram negative cells with more layers; more impervious
(its integrity can be interupted by dissolving the lipids on the OM) |
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Some bacterial groups have atypcal cell walls
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Mycobacterium and nocardia
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Mycobacterium and Nocardia have ____ faty acid or cord factor.
They have thick, waxy natrue to cell wall which is responsible for ____ which is the basis for the _____ to diagnose tuberculosis and leprosy |
mycolic acid
: it leads to their pathogenicity high resistance to certain chemicals and dyes Acid fast stain |
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Mycobacterium does not have cell wall
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NO. MYCOPLASMA does not have cell wall.--> cell membrane functions both support and transport.
Mycobacterium has atyipical cell wall. |
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Myplasma has ______ in cell membrane to control the permeability of cell substances. Its shape is a type of ____.
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sterols, pleomorphism.
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L forms (wall deficent froms) can be made artificially.
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yes by penicilin or lysozyme.
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Gram negative cell if losing its cell wall becomes _____; gram positive becomes _____
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spheroplast, protoplast
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How are the membranes dynamic?
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The lipid phase of the cell membrane is in motion where proteins can move freely
-> allows intaking food and excreting wastes or etc. |
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What is the importance of having the lipid phase of the cell membrane?
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It provides some protective barrier for better integrity of the cell's inner substances.
-controls cell permeability - regulate transport of molecules |
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Sterols:mycoplasmas= ____; archaea
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unique branched hydrocarbons unlike fatty acids of the sterols
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Mesosomes are found in gram positive bacteria not in gram negative bacteria.
Their functions:____ |
No. Just prominent in the positive.
increase internal surface area for better cell membrane activities, cell wall synthesis, guide duplicated bacterial choromosomes during cell division. |
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Cell Membrane of bacteria does ////
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-regulate transport, secretion
-energy reactions, nutrition processsing and synthesis of ATP...(it does not have metochondria) |
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Bacterical choromosome
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single circular strand of DNA(some have multiple or linear chromosomes)
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DNA and plasmid are important to carry information needed for bacterial maintenance and growth.
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NO. plasmids are nonessentail parts of DNA that may or not be in the chromosome.
-may be passed on to offspring. (like reistance) |
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Cytoplasm is composed of
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amino acides, sugar, salt, water
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Prokaryotic ribosome has ribosomal density of
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70S
Eukaryotc-80S |
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Bacterical DNA in choromosome is tightly coiled around ___
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a protein => in a dense area called nuceoid
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Plasmids
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-may encode antibiotic resistance, tolerance to toxic metals, enzymes and toxins
- used in genetic engineering; readily manipulated and transferred from cell to cell |
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Difference between inclusion and granules
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they are both storage bodies
-Inclusions: food storage (organic substances;glycogen, poly b-hydroxybityrate), bounded by a single membrane -granules: not membraned, has inorganic compounds *metachromatic granules are building blocks for necleic acid and ATP synthesis |
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Sporulation is not a menas of reproduction of endospores
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yes
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Germination of endospores?
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returning to vegetative growth
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endospores by some Gram positive gnera
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clostridium, bacililus and Sporosarcina
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Bacterial actin
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help stabilizing shape
similar to actin filaments in eukaryotes |
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Sporangium forms in this condition:
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depletion of nutriends especially amino acids
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Heat resistance is possible in endospores because of
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high content of calcium and dipicolinic acid dehydrate the cells and prevent damages from the heat
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Germination of endospores occurs when
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water is present
with the agent of amino acid or an inorganic salt -> the agent helps forming hydrolytic enzymes y endospore membranes to digest cortex and expose core to water |
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Most of the spore-forming bactera are harmful
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No.
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Endospores are especially important
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in food-canning industry for its potential to contaminate the foodYes
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Bacterial cells can be classified based on...
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cell wall that forms its figures
colonial arrangement size |
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A type of Bacillus that is gently curved :___
the other one that is short and plump:___ |
vibrio; coccobacillus
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Cell wall is rigid to retain its structure ad does not change
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No. It can change with nutrition and hereditary differences.
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Cocci/ Bacilli has more variety of colonial arrangement
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cocci
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Sporangium forms in this condition:
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depletion of nutriends especially amino acids
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Heat resistance is possible in endospores because of
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high content of calcium and dipicolinic acid dehydrate the cells and prevent damages from the heat
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Germination of endospores occurs when
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water is present
with the agent of amino acid or an inorganic salt -> the agent helps forming hydrolytic enzymes y endospore membranes to digest cortex and expose core to water |
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Most of the spore-forming bactera are harmful
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No.
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Endospores are especially important
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in food-canning industry for its potential to contaminate the foodYes
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Bacterial cells can be classified based on...
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cell wall that forms its figures
colonial arrangement size |
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A type of Bacillus that is gently curved :___
the other one that is short and plump:___ |
vibrio; coccobacillus
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Cell wall is rigid to retain its structure ad does not change
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No. It can change with nutrition and hereditary differences.
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Cocci/ Bacilli has more variety of colonial arrangement
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cocci
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Sporangium forms in this condition:
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depletion of nutriends especially amino acids
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Heat resistance is possible in endospores because of
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high content of calcium and dipicolinic acid dehydrate the cells and prevent damages from the heat
|
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Germination of endospores occurs when
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water is present
with the agent of amino acid or an inorganic salt -> the agent helps forming hydrolytic enzymes y endospore membranes to digest cortex and expose core to water |
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Most of the spore-forming bactera are harmful
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No.
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Endospores are especially important
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in food-canning industry for its potential to contaminate the foodYes
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Ribosomes are in bacterial cell membrane?
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Yes
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Bacterial cells can be classified based on...
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cell wall that forms its figures
colonial arrangement size |
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A type of Bacillus that is gently curved :___
the other one that is short and plump:___ |
vibrio; coccobacillus
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Cell wall is rigid to retain its structure ad does not change
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No. It can change with nutrition and hereditary differences.
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Cocci/ Bacilli has more variety of colonial arrangement
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cocci
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Classification is/ is not enough to identify "prokaryotes"
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IS NOT
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classification systems in the procaryotae
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1. microscopic morphology
2.macroscopic morphology -colony appearance 3. physiological/ biochemical characteristics 4. chemical anaylsis 5.serological analysis 6. Genetic and molcular analysis |
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since PHENETIC classification method is not enough, now _____is used as a major resource for that purpose.
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Bergey's manual of systematic bacteriology
, PHYLOGENETIC |
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Thermal vents , Aquifex and radiation resistant Deinococcus are in Archaea
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NO.
they are bacteria. |
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Phylum proeobacteria
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-gram negative
-obligate intracellular parasites : rickettsias |
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Phylum Frimicutes
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-gram positive
-low G+C |
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Phylum Actinobacteria
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- gram positive
-high G+C |
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Phylum Tenericutes
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bacterial without cel walls like Mycoplasma
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Medical microbiologists assuredly use the phenogenetic methods to identify bacteria
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No. they use phenotypic qualities in identification--> limited to bacterial disease agents not on nomenclature
- divides based on cell wall structure, shape, arrangement, physiological traits |
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Species of bacteria can be divded into ___
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subspecies= strains and types
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Bacteria from a single parent with different metabolism
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different strain or variety (Flagella...)
*they are called biovars or morphovars |
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subspecies that show differences in antigenic make up (serotype/ serovar)or susceptibility to bacterial viruses (phage type), and pathogenicity (pathotype)?
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TYPE
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Bacteria is heterotrophic
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NOt all-photosynthetic bacteria exist
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Cyanobacteria has gram negative cell walls that have ____ which convert N gas into a usuable form to plants.
They have ___ that makes them float. |
cysts; gas inclusions
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Green and Purple Sulfur Bacteria
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have bacteriocholorophyll
- makes sulfur not oxygen -in anaerobic condition |
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Gliding, fruiting bacteria are gram ___ bacteria that live in water and soil.
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NEGATIVE
- no flagella -many morpho forms |
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Eukaryo/prokaryo/archea
: which is known to be the most ancient? |
ARCHAEA
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Since Rickettsias and Chlamydias are OIP, they are close to virus.
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HmmmNO. they are still bacteria with celluar structure.
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What isOIP -gram negative?
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Rickettsias
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what OIP cuases eye infection, secually transmitted diseases?
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Chlamydias
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Unique characteristics of ARCHAEA?
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- unique membrane lipids and cell contstruction
- in extreme habitats -unique genetic sequences in r RNA |
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Sulfur reducers are bacteria/ archaea?
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ARCHAEA
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archaea is adapted to:
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hit
salt acid PH pressure atmosphere |