Eukaryotic Microbes Flashcards 5

Flashcards on Eukaryotic Microbes

Algae

Photosynthetic, eukaryotic organisms belonging to the Kingdom Protista. Studied in Phycology. Possess cytoplasm, cell wall, cell membrane, nucleus, plastids, ribosomes, mitochondria, and Golgi bodies. Can be unicellular to multicellular, arranged in colonies or strands, produce energy through photosynthesis, and appear in different colors depending on pigments.

Diatoms

Usually unicellular algae found in freshwater and seawater, classified as phytoplankton. Known for potential use in drug delivery and nanotechnology.

Dinoflagellates

Unicellular, flagellated, photosynthetic algae that are classified as phytoplankton. Responsible for 'red tides' and can be found in ponds as green algae. Produces oxygen.

Desmids

A division of green algae; Highly symmetrical, attractive and diverse in forms; Found mostly in fresh water; Unicellular and form chains of cell called filaments. Reproduce through asexual fission.

Protothecosis

A very rare human infection caused by algae. Begins as a subcutaneous lesion that progresses to wart-looking lesion and can be debilitating or fatal in the lymphatic system. Can release phycotoxins.

Protozoa

Eukaryotic organisms belonging to the Kingdom Protista, studied in protozoology. Most are unicellular, free-living in soil and water, and do not have cell walls. Animal-like cells that ingest algae, yeasts, bacteria and smaller protozoans

Amebae

Protozoa that move by pseudopodia (ameboid movement). Entamoeba histolytica causes amebic dysentery. Fluids are ingested in a process known as pinocytosis.

Ciliates

Protozoa that move by hairlike cilia exhibiting an oarlike motion. Transmitted to humans from drinking water contaminated with swine feces (Balantidium coli). Mostly asymptomatic but some experience persistent diarrhea, abd. Pain and perforated colon

Flagellates

Protozoa that move by whiplike flagella exhibiting a wave like motion. Examples include Trypanosoma brucei (African sleeping sickness), Trichomonas vaginalis (trichomoniasis, STD), and Giardia intestinalis & lambdia (diarrheal disease).

Nonmotile Protozoa

Protozoa lacking pseudopodia, flagella, or cilia, such as Plasmodium spp. (malaria) transmitted by Anopheles mosquitoes, Cryptosporidium parvum (cryptosporidiosis) in patients with AIDS, and Babesia spp. (babesiosis).

Fungi

Diverse organisms classified across 3 kingdoms, with pathogenic fungi in the kingdom Fungi (Eumycota). Studied in mycology. Includes yeasts, moulds and mushrooms that are saprophytes. Fungal cell wall contains chitin and can be unicellular or grow as filaments called hyphae.

Sexual Spores

Spores produced by fusion of 2 gametes. Classified taxonomically by type of sexual spore they produce or the structure which the spores are produced (e.g., ascospores, basidiospores and zygospores).

Asexual Spores

Spores produced in sac-like structure called sporangium (sporangiospore) or from fungal component called conidiophore (conidia) which are carried by wind and resistant to elements which causes allergies to humans

Zygomycotina

Lower fungi that include common bread moulds and other fungi causing food spoilage.

Ascomycotina

Higher fungi known as sac fungi or ascomycetes, including yeasts like Candida species, Aspergillus, penicillium and plant pathogens.

Basidiomycotina

Higher fungi including yeasts like Cryptococcus, some skin and plant pathogens, and large 'fleshy fungi' like mushrooms and puffballs.

Deuteromycotina

Fungi Imperfecti with undiscovered sexual form or lost ability to reproduce sexually. Includes Candida albicans, which causes yeast infection.

Yeasts

Unicellular fungi lacking mycelia, reproducing through budding, and forming pseudohyphae. E.g., Saccharomyces cerevisiae ('baker’s yeast') ferments sugar to alcohol under anaerobic condition

Moulds

Fungi with cytoplasmic filaments or hyphae making up the mycelium that extends above the surface (aerial hyphae) or beneath the surface (vegetative hyphae). Reproduction is through spore formation (sexually or asexually)

Dimorphic Fungi

Fungi that can live as yeast or moulds depending on temperature (unicellular at 37 C, moulds at 25 C). Includes human pathogens like Histoplasma capsulatum and Sporothrix schenckii.

Microsporidia

Obligate intracellular parasitic fungi (new in Eumycota) that possess a polar filament to penetrate recipient cells and cause eye or GIT infections.

Mycoses

Fungal infections caused by moulds & yeasts, classified as superficial, cutaneous, subcutaneous, or systemic.

Dermatophytes

Fungi that causes tinea infections (ringworm). Examples include tinea pedis (athlete’s foot), tinea unguium (nail infection), and tinea capitis (scalp infection).

Candida albicans

Opportunistic yeast that causes oral thrush, skin thrush, and vaginitis (candidiasis) when microflora is reduced.

Systemic Mycoses

Severe fungal infections of internal organs, often arising from inhaled conidia (e.g., blastomycosis, coccidiodomycosis, cryptococcosis, and histoplasmosis).

Lichens

Colored, circular patches on tree trunks & rocks; combination of algae and fungus and includes yeast embedded in the cortex. Represents mutualism in symbiotic relationships.

Slime Moulds

Organisms found in soil and on rotting logs with fungal and protozoal characteristics, transferred to the Kingdom of Protozoa. Starts as ameba to multicellular organism and not know to cause human disease