Mycology 410: Lecture 2

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Mycology 410: Lecture 2
2014-01-27 09:50:06
Mycology 410

Mycology 410
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  1. Useful Fungal Metabolites
    • Secondary:
    • -Antibiotics (penicillin, cephalosporins)
    • -Other drugs (cyclosporine, lovastatin)
    • -Mycotoxins (aflatoxin, trichothecines, gliotoxin)
  2. Funguses are commonly what kind of organisms
    Saprophytes or symbionts (mutualists and parasites)
  3. Saprobes (saprophytes)
    • Heterotrophs: use non-living organic material for fuel
    • Important scavengers
    • Important in nutrient recycling
  4. Examples of fungal mutualists
    • Mycorrhizae: associations of fungi with plant roots
    • Lichens: associations of fungi with algae or cyanobacteria
    • Endophytes: fungi that live within the cells of plants
  5. Fungi are the ___ most diverse group
    2nd (after bugs)
  6. Fungal Biology
    • -Eukaryotic
    • -Non-vascular (no transport tissues)
    • -Heterotrophic
    • -Reproduce via spores
    • -Sexual and aesexual cycles
    • -Typically non-motile
    • -Cell walls of Chitin
  7. Funal cells wall components
    • Polysaccharide units: Mannans, Glucans, Chitin
    • Protein fibrils
    • Ergosterol (cholesterol substitute)
  8. Environmental Factors for fungi
    • Water is essential
    • mesophillic (mild temperatures i.e. 15-40 degrees celcius, more tolerant species do exist though)
    • Fungi acidify their environment, more tolerant of low pH
    • No absolute requirement for light for growth, most need light to sporulate
  9. Vegetative growth
    • Single celled: Yeast
    • Multi-cellular: mycelium (apical growth)
  10. Characteristics of Hyphae
    • Polarized, apical growth
    • Branching occurs behind hyphal tip
    • Can septations or aseptate
    • Growing hyphae have aggregations of vesicles at apices/growing regions, this is how they grow
  11. Spitzenkorper
    Structure made up of tiny vesicles that facilitates the elongation of a hyphae, It pushes vesicles with growth materials to the tip of the hyphae
  12. How do Fungi differ from other heterotrophs
    Most ingest then digest, not digest then ingest
  13. What are the implications of exoenzymes
    Fungi can grow through substrates
  14. Where do branches/septums form on a hyphae
    Behind the apical tip once it has moved a sufficient distance
  15. Septums do what to cytoplasm
    They do not impede it's travel not that of organelles, fungi are only kinda 'multicellular'
  16. Woronin bodies
    Plug up septums when growth needs to end (i.e tip of hyphae cut off, do not want the cytoplasm to go everywhere)
  17. Mycelia are diploid of haploid?
    Haploid, can produce aesexual spores
  18. A diploid hyphae is called what?
    Dikaryotic, two hyphae grow together, become (n+n) not technically truly diploid
  19. Process of two hyphae coming together but not merging nuclei
  20. Process of nuclei merging in fungi
  21. What makes fungal taxonomy difficult?
    Could have been categorized twice in sexual/aesexual forms. When know, the teleomorphic classification is used (not the aesexual anamorphic)
  22. Fungi are closer to ___ then ___
    Animals, plants
  23. Four major phyla of Fungi:
    • Chytridiomycota: sexual/aesexual spores are motile, posterior flagella
    • Zygomycota: sexual spores are thick walled resting spores called zygospores
    • Ascomycota: spores borne internally in a sac called an ascus
    • Basidiomycota: spores borne externally on a club-shaped structure called a basidium
    • "deuteromycetes": Fungi Imperfecti, have no sexual stage
  24. Funal effects on humans
    • Mycotoxicosis: illness borne of eating metabolites of fungus, not the fungus
    • Mycosis: fungus invades human tissue
    • Mycetismus: illness caused by eating the fungus (toxic fungus)
    • Mycoallergies: allergic reaction