Fungi

• Kingdom Fungi


  Eukaryotes, fungus is called
• Fungi


  • Cell wall made of chitin, a carbohydrate (same compound as exoskeleton of insects!!!!)
  • Most multicellular: mushrooms, molds
  • Some unicellular: yeasts
  • Heterotrophs: decomposers, some parasites
  • Body made is made of filaments called hyphae
  • Reproduce using spores
• Mycelium


  The body of a fungus, a matt of thin, tangled threads
• Hyphae


  The individual thread like strands of cells
• Hyphae are one cell thick but many cells long
• Reproduction of mushrooms


  1. Mushrooms reproduce using spores

  2. Spores are small reproductive cells released from the gills

  3. Mushrooms can also reproduce when hyphae break off and grow on their own
• Fungi


  • Most are decomposers, break down organic material like dead animals, plants, etc.
  • They feed by releasing digestive enzymes that break down organic compounds, then the cells (hyphae) absorb the digested compounds
  • Some are parasites, feed on other living organisms
• Fungal infections


  • Athlete's foot
  • Candida albicans (vaginal and mouth yeast infections)
• Candida albicans (yeast infection) is usually kept in check by competition with bacteria, but this balance can be upset by antibiotics that kill the bacteria
• Useful fungi


  • Some produce antibiotics like Penicillium notatum making Penicillin
  • Used to make cheese like blue cheese with Penicillium roquefortii
  • Yeast (Saccharomyces cerevisiae) used to make bread, wine, beer
• Lichens


  Symbiotic relationship between a fungus and a photosynthetic organism (algae or cyanobacteria)
• Lichens are made of densely packed hyphae with a layer of algae/cyanobacteria and loosely packed hyphae
• Some mushrooms contain deadly toxins, don't touch unknown mushrooms! Hallucinogens in some (high doses deadly)
• Importance of fungi to humans

  • Diseases like yeast infections
  • Food spoilage from molds
  • Mycorrhizae allow more robust plant growth
  • Succession restores soil
  • Food sources like mushrooms
  • Fermentation of alcoholic beverages
• The cellulase enzyme allows fungi to act as decomposers, essential in every food web
• Fossils of fungi are rare because of their composition of soft materials and ability to form protective spores
• Fungi do not make their own food, they absorb their food
• Fungi resemble plants in that they both have cell walls
• Stinkhorns mimic the odor of rotting meat to disperse their spores using flies
• Bread rises because fermentation by yeast produces carbon dioxide
• Penicillium is the source of the antibiotic penicillin
• An important role of fungi in an ecosystem is breaking down dead organisms
• The growth of yeasts in moist regions of the body is kept in check by competition from bacteria
• Lichens are composed of an alga or a cyanobacterium and a fungus living together