Mycology Class Notes
Mycology- study of fungi
Bacteria- kingdom of Monera: unicellular, prokaryotic. Proteoglycans
Fungi- most are multicellular but also unicellular, eukaryotes, Heterotrophic, saprophytic, store carbohydrate in glycogen. Chitin
plants- Multicellular eukaryotes, photosynthesis: autotrophic: make own food: starch, fructose. Cell wall: “cellulose”, chloroplasts
animals- Multicellular eukaryotes, heterotrophs- glycogen, membrane: made up of phospholipid bilayer. One nucleus
prokaryotic- lack of nucleus
eukaryotes- organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes.
saprophytic- obtaining food by absorbing dissolved organic material; especially: obtaining nourishment from the products of organic breakdown and decay saprophytic fungi.
Heterotrophic an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter.
carbohydrate- glycogen
heterotrophs- an organism that eats other plants or animals for energy and nutrients.
Fungi will do - external digestion Example lactose—> lactase—> Galactosetglucose- the pill gives you the enzyme
Cell wall: “cellulose” fiber
phospholipid- no cellulose
Chitin- protein a long-chain polymer of N-acetylglucosamine, an amide derivative of glucose
Proteoglycans-used by bacteria to attach to and invade host cells, and to evade host defense mechanisms
Fimbriae- long filamentous polymeric protein structures located at the surface of bacterial cells
chloroplasts-organelles in plant and algae cells that convert light energy from the sun into chemical: energy the organelles responsible for photosynthesis
Decomposer: Break down dead things
Penicillin is a group of antibiotics that are used to treat bacterial infections.
fungi Primary uses- Break down dead things, Medicinal-Penicillin, food, building, baking/brewing, cheese (yeast)
What fungi need to grow- Food source, temp, moisture, ph
Blood is great for growing fungi: 98.6
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Fungal Cell- Has Cytoplasm, mostly water. Organelles, Mitochrondria- produces ATP. Cellular Respiration- C 6 H 12 O 6 + 6 O 2 --> 6 CO 2 + 6 H 2 O + ATP
C6H1206= Glucose: fat: protein
What does Fugus use ATP for: protein synthesises, Chitin synthesises, synthesis of DNA, Cell Synthesis (pH, Moisture, temp)
Ribosomes: protein synthesis
Golgi apparatus: an organelle in cells that processes and packages proteins and lipids. Helps package toxins. Penicillin is toxins
Nucleus- DNA replication→ protein synthesis
Hyphal wall-
Spitzenkorper- is a structure found in fungal hyphae that is the organizing center for hyphal growth and morphogenesis. It consists of many small vesicles and is present in growing hyphal tips, during spore germination, and where branch formation occurs.
Hypha (pl., hyphae) -filamentous thread of fungal mycelium
Septate-(describing hyphae) partitioned by cross walls known as septa
Mycelium-body of a fungus, most of which is underground or hidden within wood
Mycorrhiza-structure by which a fungus and a plant exchange nutrients mutually
Spore-reproductive structure of a fungus, usually a single cell contains DNA and glycogen
Thallus-(pl., thalli) the body of a fungus or a lichen
Outside the cell wall in fungi, several extramural layers may exist- including fimbriae and capsules. Fungal fimbriae are long, protein-containing protrusions appearing from the cell wall of certain basidiomycetous and ascomycetous fungi that are involved in cell to cell conjugation
Chitin is also found in- yeast cell walls and is a major constituent of bud scars . These are remnants of previous budding events found on the surface of mother cells following birth of daughter cells (buds).
The cell walls of filamentous fungi- are mainly composed of different polysaccharides according to taxonomic group. For example, they may contain either chitin, glucans, mannoproteins, chitosan, polyglucuronic acid or cellulose, together with smaller quantities of proteins and glycoproteins .
Cell wall of a fungus- The fungal cell wall is a dynamic structure that protects the cell from changes in osmotic pressure and other environmental stresses, while allowing the fungal cell to, interact with its environment. The structure and biosynthesis of a fungal cell wall is, unique to the fungi, and is therefore an excellent target for the development of antifungal drugs.
Amanita species- Most are poisonous. Do NOT eat. Most have a ring around the stem and cup like volva at the base. Many have patches on the cap. All Amanitas have a universal veil that they emerge from. Grow from the ground not on trees. Fly agaric can cause delirium and coma is eaten. Used to kill flies when mixed with milk.
Fungal Cell Make up-
Functional components of an idealized fungal cell.
Organelle or cellular structure Function
Cell envelope Comprising: the plasma membrane, which acts as a selectively permeable barrier for transport of hydrophilic molecules in and out of fungal cells; the periplasm, containing proteins and enzymes unable to permeate the cell wall; the cell wall, which provides protection, shape and is involved in cell–cell interactions, signal reception and specialized enzyme activities; fimbriae involved in sexual conjugation; capsules to protect cells from dehydration and immunecell attack.
Nucleus Relatively small. Containing chromosomes (DNA–protein complexes) that pass genetic information to daughter cells at cell division and the nucleolus, which is the site of ribosomal RNA transcription and processing.
Mitochondria Site of respiratory metabolism under aerobic conditions and, under anaerobic conditions, for fatty acid, sterol and amino acid metabolism.
Endoplasmic reticulum Ribosomes on the rough ER are the sites of protein biosynthesis. Proteasome Multi-subunit protease complexes involved in regulating protein turnover.
Golgi apparatus and vesicles Secretory system for import (endocytosis) and export (exocytosis) of proteins.
Vacuole Intracellular reservoir (amino acids, polyphosphate, metal ions); proteolysis; protein trafficking; control of cellular pH. In filamentous fungi, tubular vacuoles transport materials bidirectionally along hyphae.
Peroxisome Oxidative utilization of specific carbon and nitrogen sources (contain catalase, oxidases). Glyoxysomes contain enzymes of the glyoxylate cycle.
Fungal root- What are mycorrhizae? The associations between roots and fungi are called mycorrhizae.
What do fungal roots do to help the plant?- Nutrients and water
The oomycetes, also known as “water molds”- are a group of several hundred organisms that include some of the most devastating plant pathogens. The diseases they cause include seedling blights, damping-off, root rots, foliar blights and downy mildews. One of the most infamous plant disease epidemics, the Irish Potato Famine, was caused by Phytophthora infestans (cause of late blight).
Fungi are - haploid or dikaryotic during the major part of their lifecycle, and form septate hyphae. Oomycetes are diploid during their vegetative stage, form coenocytic (nonseptate) hyphae, and produce motile zoospores with two kinds of flagella
The Oomycota were once- classified as fungi, because - of their filamentous growth, and because they feed on decaying matter like fungi. The cell wall of oomycetes, however, is not composed of chitin, as in the fungi, but is made up of a mix of cellulosic compounds and glycan.
While downy mildew is an oomycete pathogen (water mold disease), powdery mildew is a fungal disease caused by a variety of species.- It consists of a large number of microscopic spores (conidia) borne in chains. As the fungi spread on the plant, it develops structures that insert into plant cells to extract nutrients. Oomycetes also cause damping off and white rust on plants.
The Stramenopiles, also called Heterokonts- are a group of organisms distinguished by the presence of stiff tripartite external hairs. In most species, the hairs are attached to flagella, in some they are attached to other areas of the cellular surface
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Phylum Basidmycota
Characteristics of Basidiomycetes:
Haploid somatic hyphae
Chitin in the cell walls
septate hypha
Central pore in the hypha
Hypha my fuse and merge
Produce a fruiting boby
produce basidiospore
Shitake mushrooms:
Amanitas
rust
smuts toadstools
Spore Formation in Basidiomycetes
Meiosis results in the formation of 4 basidiospores
the basidiospores
Ustillaginomycotin - Smuts attack fruits/seeds and cause them to swell into galls
Haploid- Cells with one nucleus and one set of chromosomes
Yeast:
Anamorph- asexual
Telomorph- sexual
Dimorphic: two forms, two shapes, unicellular, pseudohyphae
Yeast needs: organic substrate for engergy usually carboohydrates like sucrose, maltose, glucose, and fructose.
Mositure that is number one
Grow best neutral or slightly acidic pH
grow in aerobic conditions
common in the enviroment, berries and plant, soil
Asexual Reproduction of yeast
-sycromisties
Budding via mitosis
some yeast are ascospores (produce 4 yeast spores)
Sexual reproduction in yeast
-this usually occurs when the yeast is stressed as in not having enough nutrients or dessication
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250 species of yeast only 24 interact with other foods
Lichens:
Are symbiotic organisms. Main components: fungus and alegae
lichens need moisture
Fungal partner provides:
Structural framework
protection
physiological and ecological features.
Crustose lichens:
tightly attached