Shared Flashcard Set

Details

Ch 11 and 12
Archea and Fungi
49
Microbiology
Undergraduate 2
07/24/2010

Additional Microbiology Flashcards

 


 

Cards

Term
Archea
Definition
-membranes composed of branched hydrocarbon carbon chains attached to glycerol by ether linkages
-no peptidoglycan
-no sensitive to muramic acid or D-amino acids (antibiotics)
-unique rRNA
-extremophiles
Term
Sulfolobus
Definition
-aerobic, irregularly lobed, spherical bacteria
-thermoacidophiles
-oxidize sulfur to sulfuric acid
Term
Thermoproteus
Definition
-long thin bent or branched rods
-strict anaerobes
-temp optima 70-97
-PH optima 2.5 -6.5
-grow in hot springs and hot aquatic habitats containing sulfur
Term
methanogens
Definition
-strict anaerobes that obtain energy by converting CO2, H2, formate, methanol, acetate to methane (and CO2 sometimes)
-suggested earliest organisms
-thrive in anaerobic environments rich in organic compounds
-great potential importance
Term
Thermoplasma
Definition
-no cell wall
-found in coal mine refuse
-optimum temp and pH 55-59 degrees C, 1-2pH
Term
Picrophilus
Definition
-aerobic
-grows between 47-65 deg C
-only grows under 3.5 pH
-optimum .7
Term
mycology
Definition
study of fungi
Term
3 exmaples of fungi
Definition
yeast, mold, fleshy
Term
fungi characteristics
Definition
-eukaryotic
-rigid cell wall
-chemoheterotrophs (require organic compounds for both carbon and energy sources_
-obtain nutrients by absorption
-obtain nutrients as saprophytes (live off decaying matter) or as parasites
Term
fungi are involved in...
Definition
-animal/plant diseases
-food spoilage
-decomposition of organic material
-recycling organic compounds in nature
-production of antibiotics
Term
fungal cell wall
Definition
-no peptidoglycan, teiochic acids, or polysacharrides
-contain peptidomannan (mannose polymer antigenic to humans)
-contain glucans (glucose polymers for strength)
Term
chitin
Definition
-long unbranched chains of poly N acetyl glucosamine
-structural support
Term
fungal plasma membrane
Definition
-contains ergosterol
-major target of antifungal drugs
Term
hyphae
Definition
-basic morphological unit of all fungi
-branching threadlike tubular filaments
-septate
-coenocytic
Term
septic hyphae
Definition
-contains septa (cross walls) that divide them into distinct units with one nucleus
Term
conenocytic
Definition
-long continuous cell with manu nucelei
-no septa
Term
fungo elongate at...
Definition
tips by extension
Term
vegetative hypha
Definition
-portion that obtains nutrients
Term
reproductive/aerial hypha
Definition
portion involved in reproduction
Term
mycelium
Definition
mass of hypha
Term
yeasts
Definition
-Unicellular
-Usually appear as oval cells 1-5 μm wide by 5-30 μm long
-typical eukaryotic structures
-thick polysaccharide cell wall-
-Facultative anaerobic
-Reproduce asexually by budding or fission
-S. cerevisiae
-S. pombe
Term
dimorphic fungi
Definition
-exist in mycelial or yeast morphology depending on environment
-Candida albicans
-Histoplasma capsulatum
Term
fungal reproduction
Definition
1. Budding
2. Fission
3. Hyphae fragmentation (tubular filaments)
4. Sporulation
Term
budding
Definition
-uneven cytoplasmic division
Term
fission
Definition
even cytoplasmic division
Term
hyphae fragmentation
Definition
each part is capable of growth by elongating at tip
Term
sporulation
Definition
-can be asexual or sexual
-not same as bacterial spores
Term
asexual spores
Definition
-conidiospores
-sporangiospores
Term
conidiospores
Definition
-unicellular or multicellular not enclosed in a sac
-conidia are produced in a chain at the end
-Aspergillus produces conidiospores
-Candida albicans and Cryptococcus produce blastoconidia (buds coming off
the parent cell)
-Candida albicans also produces chlamydoconidia (thick-walled spore
formed by rounding and enlargement within a hyphal segment
Term
sporangiospores
Definition
-formed within a sac (sporangium) at the end of sporangiophore
-can contain hundreds of sporangiophores
-Rhizopus produces sporangiospores
Term
sexual spores phases
Definition
-plasmogamy
-karyogamy
-meiosis
Term
plasmogamy
Definition
Haploid nucleus of a donor cell (+) penetrates the cytoplasm
of a recipient cell (-)
Term
karyogamy
Definition
The donor (+) and recipient (-) nuclei fuse to form a diploid
zygote nucleus
Term
meiosis
Definition
The diploid nucleus gives rise to haploid nuclei (sexual spores)
Term
Zygomycota
Definition
-asexual reproduction through sporangiospores
-sexual reproduction through zygospores
-cause serious infections particularly in diabetics and people with immune deficiency
-zygomycosis is potentially lethal and can affect fetus
-Rhizopus stolonifer, the common black bread mold
Term
Ascomycota
Definition
-reproduce asexually through conidia
-sexual reproduction results in ascospore occurs in ascus
-Aspergillus flavus, which grows on peanuts generates
aflatoxin, which damages the liver and is highly carcinogenic
-Candida albicans, a yeast which attacks the mucous membranes, can
cause an infection of the mouth or vagina called thrush, and is also blamed
for "yeast allergies"
Term
Basidiomycota
Definition
-includes fungi that produce mushrooms
-most reproduce sexually by club shaped basidia that bear external basidiospores
-Cryptococcus neoformans is the most prominent medically important
species
-causes meningitis and
meningo-encephalitis in people with HIV/AIDS
-There are about 37 recognized species of Cryptococcus, the majority
living in the soil and are not harmful to humans
Term
classification of fungal species (based on site of infection)
Definition
-superficial mycoses
-subcutaneous mycoses
-opportunistic mycoses
-systemic mycoses
Term
4 virulence mechanisms
Definition
-produce a capsular polysaccharide
-metabolize keratin (colonization of epidermis, hair, nails)
-grow at host temp (37) as well as temp or normal environment(25)
-can survive in lowered oxidation-reduction state, situation found in damaged tissues
Term
producing a capsular polysaccharide...
Definition
-isolates organism from surrounding environment
-plays role in triggering immune response
Term
superficial mycoses
Definition
-cause infections of outermost layers of skin and hair
-common
-include ringworm and athlete's foot
-tissue damage is minimal and rarely induces immune response
Term
subcutaneous mycoses
Definition
-development of lesions at sites of infection
-involves deep layers of epidermis like subcutaneous or bone
-feet, legs, arms, hands, butt
-commonly found in soil or decaying vegetation
-hard to treat, requires surgery
-Sporotrichosis found mostly in
gardeners and farmers
-Chromoblastomycosis. Pigmented fungi
in the soil may cause this disease
Term
Candida species
Definition
-Most commonly causes vaginitis, thrush, balanitis, and cutaneous infections
-women with diabetes, taking contraceptives, having menopause are more prone to vaginitis (high sugar low pH)
-150+ species
-few are important pathogens
-C. albicans is part of the normal flora
-can cause opportunistic infections in people who are immunosuppressed, debilitated, or received prolonged antibacterial therapy
Term
opportunistic mycoses
Definition
-caused by fungi found in environment or in normal flora
-may take advantage of weaker host and causes disease
-most common are candida, aspergillus, pneumoncystis
Term
symptoms of opportunistic mycoses
Definition
-thrush (infection of tongue/oral muscosa often seen in HIV)
-esophagitis (painful swallowing, chest pain)(hematologic disease/HIV)
-vaginitis (women pregnant, diabetic, receiving antibiotics)
-chronic mucocutaneous candidiasis (lesions on face, scalp, hands, defects in T cells)
Term
Pneumocystis carinii
Definition
-widespread in environment
-doesnt cause illness in healthy people
-causes lung infection in people with weak immune systems, AIDS, organ/bone marrow transplant, premature/malnourished children
-prior to AIDS, p. carinii pneumonia was rare
Term
control of fungi
Definition
1. Antibiotic griseofulvin interferes with nuclear division by binding to tubulin
2. Antimetabolites interfere with normal nucleic acid synthesis.
3. Antibiotics such as amphotericin B, pimaricin, and nystatin are fungicidal drugs
that bind to ergosterol and cause leakage of cellular contents
4. Antibiotics such as clotrimazole, miconazole, itraconazole interfere with
ergosterol biosynthesis
5. Naftifine (Naftin) and terbinafine (Lamisil) block synthesis of ergosterol
Term
systemic mycoses
Definition
-caused by most virulent fungi
-may cause serious progressive systemic disease
-primarily originate in lung but may spread
Term
Useful fungi
Definition
-baking and brewing (S. cerevisiae)
-antibiotics (penicillin, cephlosporin)
-citric acid in Coke (Aspergillus niger)
-steroids and hormones (birth control pill)
-cheese
Supporting users have an ad free experience!