Fungi
Make your own free website on Tripod.com
Basic Fungi Information
Nutrition
  • Fungi are usually heterotrophs meaning they derive their energy from other organisms.
  • They ingest their food through the process of absorption.
    • Small organic molecules are absorbed from the surrounding environment.
    • They digest their food outside their body by secreting powerful hydrolytic enzymes into the food.
    • These enzymes decompose complex molecules to the simply compounds that can be absorbed.
  • Their aborptive mode of nutrition seperates the fungi into 3 distinct types:
    • Saprobic - Energy from nonliving organic material such as dead things.
    • Parasitic - Energy from cells of living host.
    • Mutualistic - Energy from another organism, however they reciprocate with function. Meaning it is beneficial for both.
Habitat
  • Fungi live almsot everywhere on the planet, on both land and water.
  • Their usual habitat is associated soemhow to another organism.
Structure
  • The vegetative bodies of most fungi is usually hidden, being diffusely organized around and within the tissues of their food sources.
  • The body of the fungi is composed of basic building units called hyphae which are minute threads of tubular walls surrounding the plasma membrane and cytoplasm.
  • When combined, hyphae form an interwoven mat called mycelium the "feeding" network of a fungus.
  • Hyphae are usually divided into cells by crosswalls called septa.
  • Septa usually have pores large enough to allow ribosomes, mitochondria and even nuclei to flow from cell to cell.
  • Fungi cell walls are made of chitin a nitrogen containing polysaccharide wall.
  • Some Fungi are aseptate meaning their hyphae are not divided by septa. These type of fungi are called coenocytic fungi.
  • Some fungi have haustoria which are modified hyphae that penetrate their host to absorb nutrients.
Growth
  • Fungal mycelium grows rapidly sometimes up to a kilometer a day.
  • This is because fungi usually concentrate in adding hyphal length rather than girth.
  • Since they are nonmotile, mycelium makes up for it by swiftly extending the tips into new territory.
Reproduction
  • Fungi reproduce by releasing spores that are [produced either sexually of asexually.
  • These sproes come in all shapes and sizes and are spread by wind and water.
  • When conditions are stable, fungi usually reproduce asexually to clone themselves rapidly.
  • When environmenal conditions are changing, fungi usually repoduce sexually to adapt to the changes.
  • A form fo sexual reproduction for fungi is called syngamy which is the sexual union of cells from two individuals.
    • Syngamy occurs in two stages; Plasmogamy and Karyogamy.
      • Plasmogamy is the fusion of the cytoplasm.
      • Karyogamy is the fusion of the nuclei.
    • Dikaryon is a process that occurs are plasmogamy when the 2 nuclei pair up but do not fuse yet.