Chapter 12

Biology 305 with Madden at George Mason University

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By: ester yang
Textbook:

Microbiology: An Introduction, Books a la Carte Edition (10th Edition)
Created: 2011-04-11
Size: 30 flashcards
Views: 30

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Fungi (nutrition, form embryo?)

Chemoheterotroph. mutilcellular except yeasts. Unicellular, filamentous, flesh. Absorbs food. Sexual/asexual spores. no embryo formation.

Fungi characteristics (metabolism, pH, environment)

Optimum pH of growth: ~5 pH
more resistant to high osmotic pressure. grow in high sugar/salt. require less nitrogen than bacteria. can metabolize complex carbs.

Molds (body)

Thallus- body of mold/fleshy fungus. long filaments of cells joined together.
Hyphae- the long filaments. can grow to huge proportions.
Mycelium- mass of hyphae
Septa- cross walls in hyphae. divides in cell-like units.
Vegetative hypha: obtains nutrients
Reproductive/aerial: projects above surface.

Yeast (buddy, fission)

Nonfilamentous. Unicellular, typically spherical/oval. can do facultative anaerobic growth.
Budding: divide unevenly
fission: divide evenly

Dimorphic Fungi

Dimorphism: 2 forms of growth: either mold or yeast.
mold forms: vegetative/aerial hyphae
yeast: budding

Pathogenic d. Fungi: yeastlike (37 C) moldlike (25 C)

Asexual Reproduction (conidiospore, conidiophore)

Asexual spores formed by hyphae. Germination results in identical progeny. No fusion of nuclei of cells.

Conidiospore/condium: unicell/multicellular spore not in a sac. Conidia are made in a chain at the end of a conidiophore (aerial hyphae with conidiospores)

Arthroconidi, Bastoconidia, Chlamydoconidium, Sporangiospore

Conidia formed by fragmentation of septate hypha into individual, thickened cells.
ex: Coccidioides immitis

Bastoconidia: buds coming off parent.
ex: Candida albicans, cryptococcus

Chlamydoconidium: thick walled spore from hyphal segment.

ex: C. albicans

Sporangiospore: formed in sac (sporagium). made by Rhizopus.

Sexual Spores (plasmogamy, karyogamy, meiosis, zygospore)

Plasmogamy: fusion of cytoplasm of 2 cells. haploid nucleus of donor cell penetrates cytoplasm of recipient cell

Karyogamy: Fusion of nuclei of 2 cells. Form diploid zygote nucleus.

Meiosis: diploid nucleus makes haploid nuclei

Zygospore: fusion of haploid cells: 1 zygospore

Sexual Spore cont (Ascospore, Basidiospore)

Ascospore: formed in ascus. results from fusion of nuclei that can be morphologically similar or different.

Basidiospore: formed outside on a pedestal (basidium)

Telomorphs, anamorphs

T: make both sexual/asexual spores.
A: asexual, lost ability to sex

Medically important Phyla of Fungi

Zygomycota

Ascomycota

Anamorphs

Basidiomycota

Zygomycota (asexual, sexual, what kind of fungi? )

conjugation fungi
coneynocytic
make sporangiospores (asexual) and zygospores (sexual)

Ascomycota (what do they produce, asexual/asexual?)

sac fungi
septate
teleomorphic fungi
Ascospores and frequently conidiospores

Anamorphs

make Asexual spores only
rRNA sequence mostly in Ascomycota, few in Basidiomycota
Ex:
Penicillium (came from mutation in a teleomorph)
Sporothrix
Pneumocystis
Candida Albicans

Basidiomycota

Club fungi (includes fungi that produce mushrooms)
Asexual (fragment breaks off) and sexual (meiosis, plasmogamy)

Septate hyphae

Produce basidiospores and sometimes conidiospores
Spores are formed outside on a base pedestal

Mycosis, Pneumocystis

chronic fungal infection
Pneumocystis: opportunistic fungus (most aids patients)

Economic uses of Fungi

-Food production
-Medicine
-Agriculture

Food production (niger, cerevisiae, trichoderma)

Aspergillus niger- makes citric acid for foods/drinks
Saccharomyces cerevisiae- makes bread and wine

Trichoderma: makes enzyme cellulase which removes pant cell walls to make fruit juice

Medicine

Taxomyces makes taxol, anti cancer drug.

Agriculture

fungi used as biological pest control
Can also be used to prevent undesired fungal growth on fruits
also decomposes plant litter/organic material

Algae

Eukaryotic plants
unicellular, filamentous, or multicellular
photoautotrophs
multicellular body: thallus
all replicate asexually, some both

Divisions of algae (Brown, red, green, diatoms, dinoflagellates)
(Their purpose?)

Brown algae (kelp): used for algin (thickener in ice cream)

Red algae: make agar

Green: mostly microscopic

Diatoms: unicellular. Silica/pectin cell walls.

Dinoflagellates: unicellular, mostly plankton. some make neurotoxins: kill fish. some make red tides.

Dinoflagellates (what's in their plasma membrane, pigments, what do they store, what do they do in animals?)

Cellulose in plasma membrane
chlorophyll a/c, carotene, xanthins
keep starch
some symbionts in marine animals

Lichen (green tree bark looking fungi)
(How do they work together?)

Combination of green alga (cyanobacter) and fungus (usually ascomycete). both benefit.

Holdfasts (hyphae) anchor lichen to surface. Algae makes carbs for fungus and fungus protects algae.

Slime molds

Amoeboid-like eukaryotic cells. both fungal/protozoan traits.
Cellular slime mold life cycle: amoebas ingest bacteria and aggregate, enclosed in a sheath forming a slug. Slug migrates and makes spore cap structure. Spores released to form amoeba.

Acellular/plasmodial slime mold life cycle:

Protozoa ( reproduction, niche, Trophozoite, cyst?)

Unicellular, eukaryotic chemoheterotrphic. in water and soil.
Trophozoite: feeding/growing stage. feeds on bacteria and nutrients.

Reproduce asexually by fission, budding or schizogony (multiple fission)

Some reproduce by conjugation (cell-cell contact)

Some make protective capsule, Cyst. lets it survive in adverse conditions.

Archaezoa (What organelle do they not have?) (Trichomonas Vaginalis, Giardia lamblia)

no mitochondria, but mitosome (similar)
multiple flagella
Trichomonas Vaginalis: no cyst so must be transferred quickly. Can be transmitted sexually or by toilet/towels.

Giardia lamblia: in small intestine of humans. Excreted in feces as cyst, survives

Amoebozoa (Entamoeba histolytica)

Move by its extensions/ projections (pseudopods)

Entamoeba histolytica- only pathogenic amoeba in human intestine. Causes amoebic dysentery. In humans, causes cell lysis.

Apicomplexa (examples?)

Not motile when mature. Obligate intracellular parasites. Complex life cycle.
Ex: Plasmodium, malaria. Grows by reproduction in Anopheles. Definitive host.

Toxoplasma gondii (cats)

Cryptosporidium- causes respiratory/gallbladder infections in AIDS patients, immunosuppressed. lives in intestine.

Euglenozoa

Move by flagella
euglenoids: photoautotrophs.

hemoflagellates: blood parasites.
Trypanosoma: kissing diseases.

About this deck

By: ester yang
Textbook:

Microbiology: An Introduction, Books a la Carte Edition (10th Edition)
Created: 2011-04-11
Size: 30 flashcards
Views: 30

About StudyBlue

“I have used this website for three exams, and I see a huge difference in my test results.”
Naj