Sporangiospore: produced in a sac-like structure called sporangia (e.g., Rhizopus).Conidiospore: a single-cell, bicellular, or multicellular structure that arises on the tip or side of a hyphal structure called a “conidiophore” (e.g., Aspergillus).Yeasts (e.g., Candida spp.) mainly reproduce using this mechanism.This fragment eventually detaches from the parent cell after the nucleus divides via mitosis and is capable of replicating using the same process.The nucleus of the parent cell divides and one daughter nucleus migrates into the bud.An outgrowth, bud, or appendage develops on the surface of the cell or the hypha, with its cytoplasm being continuous with that of the parent cell.Binary fission: a cell undergoes nuclear division and splits into two daughter cells capable of replicating.Fungal fragmentation: a portion of the mycelium splits from the body of the fungus, with the resulting fragment being capable of replication.A haploid cell is produced via mitosis and released from the parent body (e.g., hypha, sporogenous cell).Spores may be released outside or within a special reproductive structure, where they grow independently.Asexual spore production (most common mode of reproduction).Produces zygospores, which result from the union of two compatible nuclei and are genetically different from the parent bodies.Produces unicellular spores that are genetically identical to the parent body.Physiology of fungiįungi reproduce through sexually and/or asexually produced spores. To remember the temperatures at which the different forms of dimorphic fungi exist, think: Mold in the cold, yeast in the heat! Dimorphic fungi exist as molds at cooler temperatures ( cold) and as yeasts at warmer temperatures ( heat). They extract energy (e.g., sugar and proteins) from living or dead organic matter. Most commonly cause subacute pulmonary infectionsįungi represent a kingdom separate from plants and animals.Examples: Histoplasma capsulatum, Blastomyces dermatitidis, Coccidioides immitis, Paracoccidioides brasiliensis, and Sporothrix schenckii.Dimorphic fungi: fungi that can exist as both mold or yeast, depending on temperature.For clinical significance and further discussion, see “ Yeasts” and “ Molds” below.Molds: multicellular fungi, organized into hyphae.Yeasts: unicellular fungi, occasionally organize into hyphae and pseudohyphae.Monomorphic fungi: fungi that exist exclusively as either yeast or mold.Key enzymes in its synthetic pathway include squalene epoxidase and 14–α–demethylase, which converts lanosterol to ergosterol.Cell membrane component unique to fungal species.Fungal cell membrane: contains ergosterol (analogous to cholesterol in humans).Fungal cell wall: composed of chitin, glucans, and mannans.Fungi are chemotrophic organisms, i.e., they secrete enzymes to degrade organic substrates.Can be unicellular, multicellular, or dimorphic.Most are obligate or facultative aerobes.Microscopic fungi are either molds or yeasts or both. Macroconidium: a large asexual fungal sporeįungi vary widely in size and shape, from unicellular to multicellular forms.Microconidium: a small asexual fungal spore.Conidium: an asexual fungal spore formed from a vegetative yeast, hyphal cell, or a specialized conidiogenous cell. ![]() Teleomorph: sexual reproductive state of a fungus.Anamorph: asexual reproductive state of a fungus.An outgrowth produced by spores during germination.Conidiophore: simple or branched hyphae on which conidia are produced.Sporangiophore: modified hyphae bearing sporangia.May result from asexual (e.g., sporangiospores) or sexual reproduction.Haploid, reproductive particles that can be formed on reproductive hyphae or mycelium.Thallus: the vegetative body of a fungus.Pseudomycelium: mycelium-like mass of pseudohyphae.Mycelium : a haploid and multicellular network of hyphae forming a thread-like structure.Pseudohyphae can be identified by the presence of constrictions at the site of origin.A hypha-like filament formed by a chain of budding yeast cells that have not become detached from each other.Septa: hyphal cell wall divisions, typically porous.Hyphae : tubular, branching filaments of fungal cells, with or without septae.
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