Fungi Flashcards
Fungi includes these 3:
- Yeast:unicellular usually nonfilamentous
- molds:filamentous, multicellular
- fleshy fungi:mushrooms, puffballs, shelf fungus
Mycology:
Study of fungi
Is fungi eukaryotic or prokaryotic?
Eukaryotic. Has true nucleus
Hyphae:
Fungal filaments (microscopic) grow by elongation at the tips to form a mycelial mass or mycelium(visible to naked eye)
2 types of mycelium:
Vegetative mycelium
And
Aerial or reproductive mycelium
Vegetative mycelium:
Absorbs food, on surface or beneath
Aerial or reproductive mycelium:
Bears reproductive spores
Filamentous:
Fleshy fungi composed of closely packed hyphae
External digestion:
Absorptive heterotrophs: secrete digestive enzymes and absorb nutrients
Fungi contain what in the cell wall?
Chitin-rigid polysaccharide
What solutions do fungi grow in?
Hypertonic solutions, at lower pH than bacteria
Fungi are primarily saprophytic:
Decomposers which acquire nutrients from dead or decaying organic matter (recyclers)
Industrial uses for fungi?
Bread, wine, cheese, source of antibiotics including penicillin
How many known fungi species?
100,000 known only 100 are pathogenic to man or animals. (Most are plant pathogens)
Fungi reproduction;
- Both asexual and sexual reproduction by true reproductive spores.
- spores form on the aerial mycelium in a variety of ways and in a variety of structures.
Asexual spores:
Sporangiospores, and conidiospores formed by mitosis.
Sexual spores:
Zygospores, ascospores, basidiospores formed by fusion of nuclei from + and - mating strains followed by meiosis
How are fungi classified?
By the type of sexual spore produced
3 types of fungi classifications?
- Zygomycota(zygospores)
- Ascomycota(ascopspores)
- Basidiomycota(basidiospores)
Most fungi species are produced asexually. True or false?
True
Mycoses:
Fungal disease
Fungi are opportunist:
Usually affect only weakened or immune compromised hosts
Fungi are long lasting:
Because it grows slowly
Fungal Infections may be:
Superficial
Subcutaneous
Deep
Superficial(cutaneous):
Dermatophytes infect skin, hair, nails and scalp(keratinized epithelium).
4 Examples of superficial fungal infections:
- ringworm(tinea)
- Microsporum
- Trichophyton
- Epidermophyton
Subcutaneous(beneath skin):
- caused by saprophytic fungi from soil and vegetation
- usually introduced by puncture
- more difficult to treat
Deep(systemic):
- usually caused by soil fungi that are inhaled and spread from lungs
- May be fatal
Zygomycota(conjugation fungi):
- sexual spores are zygospores
- asexual spores are sporangioapores
Zygomycota slide representative is Rhizopus nigricans(black bread mold):
-sporangioapores (asexual spores)
Ascomycota(sac fungi):
- Sexual spores are ascospores
- asexual spores are conidiospores
- most pathogens are Ascomycetes
4 Ascomycota representatives:
- Penicillin
- Aspergilus
- Saccharomyces cerevisiae(bakers yeast)
- Peziza
- Candida albicans
Penicillin:
- conidiospores(asexual spores)
- P. notation is source of penicillin
Aspergillus:
- Conidiospores(asexual spores)
- common in soil
- Aspergillosis: fungal pneumonia
Saccharomyces(bakers yeast):
- Reproduce by budding
- often dimorphic: differ t morphology depending on temperature (unicellular at 37C and filamentous at 25C)
Peziza:
Ascospores (sexual spores)
Candida albicans:
- Normal flora of vagina and mucous membranes
- cause of candidiasis(yeast infection) - vaginitis and thrush
- usually superficial but may become systemic in immune-compromised patients
Basidiomycota(club fungi):
- Sexual spores are basidiospores
- asexual spores are conidiospores
Basidomycota representative:
Coprinus (a small mushroom)
Coprinus:
Basidiospores (sexual spores) on basidia (the dents on slide)
