Microbiology Chapter 12: The Eukaryotes: Fungi, Algae, Protozoa and Slime Molds

Lichens—What is a lichen? Parts of a lichen.

-A mutualistic relationship between green algae and fungus -The first life form to colonize rock or soil Parts: Thallus (body) of lichens are made of: Medulla—hyphae grown around algal cells Rhizines (holdfasts)—hyphae projections below the body Cortex—protective coating over the algal layer

Basidiomycota

-Club fungi; septate hyphae -Produced asexually:conidiospores -Produced sexually: basidiospore -Formed externally on a base pedestal called a basidium

What is the environmental significance of fungi?

-Eukaryotic heterotrophs: decompose organic matter -Can metabolize complex carbohydrates -Produce both asexual and sexual spores -Fungal spores are used in identification of fungi -Most fungi grow well in acidic culture condition -Fungi tolerate low moisture conditions

Zygomycota

-Forms when nuclei of two similar cells fuse -Asexually produce sporangiospores -Sexually produce zygospores Example: Conjugation fungi and Coenocytic hyphae

Microsporidia

-No sexual reproduction is observed, but probably occurs in a host -lack mitochondria Example:Obligate intracellular parasites; ) Giardia and Trichomonas

Ascomycota

-Sac fungi; septate hyphae -Teleomorphic fungi -Produced asexually: conidiospore -Produced sexually: ascospore

What does each component of a lichen provide for the organism?

-The algal partner produces carbohydrates that are absorbed by the fungal partner; the fungal partner provides a means of attachment and protects the algal partner from desiccation.

Helminths

-They are heterotrophic. -They are multicellular animals. -They have eukaryotic cells. -Transmits diseases through gastrointestinal route -Some have male and female reproductive organs in one animal.

Protozoa

-Unicellular eukaryotes reproduce asexually -Can be found in water or soil -Some protozoan pathogens are transmitted by arthropod vectors example: Euglena

• Algae: multicellular, unicellular

-aquatic; classified as plants -They use light as their energy source. -They use CO2 as their carbon source (fix CO2 in organic molecules). -They produce oxygen from hydrolysis of water (Produce 80% of Earth's O2) -Some are capable of sexual reproduction. -can be multi or unicellular -Can produce toxins -Oil production -Symbionts of animals

hyphae

-branching filaments for vegetative growth -produces asexual spores example: chlamydoconidium

What is their environmental significance?

-they serve as primary producers in rocky ecosystems. -they are used as indicators of air pollution. -they are arranged in foliose, fruticose, or crustose morphologies. - they are a major food source for tundra herbivores.

Green algae and dinoflagellates.

Both are eukaryotic, photoautotrophs, and reproduce asexually. Algae get their color from chlorophyll a. Dinoflagellates: -Unicellular and Cellulose in plasma membrane -Neurotoxins (saxitoxins) cause paralytic shellfish poisoning -Chlorophyll a and c, carotene, xanthins -Some are symbionts in marine animals giant clams) -Store starch -Produces compounds toxic to humans; paralytic selfish poisoning; Green algae: -Cellulose cell walls -Unicellular or multicellular -Chlorophyll a and b -Store starch -Gave rise to terrestrial plants

Slime mold - What is the difference between a plasmodial & cellular

Both are members of Amoeboza Plasmodial: Mass of protoplasm with multiple nuclei; moves as a giant ameba and sporangia Cellular: Resemble amoeba; Ingest fungi and bacteria by phagocytosis; Cells aggregate to form stalks and spore caps that differentiate into spores

Fungi

Chemoheterotrophs Tolerate acidity ( grow best at ph of 5) Grow in high sugar and salt concentration (high osmotic pressures) Can metabolize complex carbohydrates (can cause ringworm)

Where does it grow and why does it grow where it does?

Locations depend on nutrient availability, wavelengths of light, and surfaces to attach

Most photosynthetic

Most algae are photosynthetic; however, the oomycotes, or fungal-like algae, are chemoheterotrophs.

Describe amebae

Move by extending pseudopods Entamoeba histolytica—causes amebic dysentery Acanthamoeba—infects corneas and causes blindness Balamuthia—granulomatous amebic encephalitis

Name two types of apicomplexas

Plasmodium: Anopheles mosquito causes malaria

What is the difference between a sporangiospore & conidiospore

Sporangiospore: Zygomycota; enclosed in a sac Conidiospores: Ascomycota; not enclosed in a sac; formed in a chain; ex. penicillium

holdfasts, blades, stipes

Thalli of the larger multicellular algae, those commonly called seaweeds, consist of branched holdfasts (which anchor the alga to a rock), stem- like and often hollow stipes, and leaflike blades

What is the difference between a yeast and a mold?

Yeast: caused by Candida Albicans Nonfilamentous and unicellular Mold: fleshy fungi that contain hyphae

septate hyphae

contain cross-walls; cells divided by septa

coenocytic hyphae

do not contain septa; continuous cells

thallus

fungal body that consists of hyphae filaments

dimorphic fungus

grows as a yeast or a mold at diff temperatures

anamorph

have spores; can't sexually reproduce

telomorph

produces both sexual and asexual spores ex. ascomycota

Rhizopus

sporangiospore zygospore

plasmogamy

stage in fungal sexual life cycle; haploid donor cell nucleus (+) penetrates cytoplasm of recipient cell (−)

karyogamy

stage in fungal sexual life cycle; + and − nuclei fuse and form diploid zygote

mycorrhizae

symbiotic fungi that help the roots of plants absorb minerals and water from the soil