Protista and Fungi Protista and Fungi Agents of Human Disease and Health
Jan 13, 2016
Protista and FungiProtista and Fungi
Agents of Human Disease and Health
Features of fungiFeatures of fungi
• Eukaryotic and mostly multicellular
• Heterotrophic– digest food by secreting enzymes outside their
bodies, then absorb the digested nutrients
• reproduce sexually or asexually by spores
• decomposers help return nutrients to soil and air
Four Divisions of FungiFour Divisions of Fungi
1. Zygomycetes
• bread mold
• Some orders can
cause disease via
inhalation of spores by
immunocompromised
individuals
Four Divisions of FungiFour Divisions of Fungi
2. Ascomycetes
• yeasts, mildews, morels, truffles
• Some types can cause a type of athletes foot
Four Divisions of FungiFour Divisions of Fungi
3. Basidiomycetes
• common mushrooms
• Cryptococcus can cause meningitis in immunocompromised individuals
Four Divisions of FungiFour Divisions of Fungi
4. Deuteromycetes
• Roquefort cheese, athlete’s foot
Ecological and economic Ecological and economic importance of fungiimportance of fungi
• mycorrhizae were important in plant evolution• lichens important in soil formation, indicator of acid rain or air
quality• antibiotics – penicillin created with ascomycetes• cyclosporine - immune suppresser useful to transplant patients• Basidiomycota – decomposers that play a significant role in
the carbon cycle • Yeast necessary for bread production and are good genetic
engineering subjects
Kingdom ProtistaKingdom Protista
• mostly unicellular, some are multicellular (algae)
• can be heterotrophic or autotrophic
• most live in water (though some live in moist soil or even the human body)
• ALL are eukaryotic (have a nucleus)
• A protist is any organism that is not a plant, animal or fungus
3 Categories3 Categories
Grouped into three major, unofficial categories based on how they obtain nutrition
1.Protozoa - Animal-like Protists
2.Algae
3.Fungus-like Protists
ProtozoansProtozoans
Groups divided by type of locomotion • feed autotrophically as well as heterotrophically• most reproduce asexually
Zooflagellates - one or more flagella•Trypanosoma causes African sleeping sickness
Sarcodines - pseudopods
Ciliates – use cilia for feeding and movement
Sporozoans – parasites that do not move independently•Plasmodium causes malaria
AlgaeAlgae
•Photosynthesize but may become heterotophic in the absence of light•Live in fresh and salt water•Reproduce asexually
Euglenophytes – have two flagella but no cell wall
Chrysophytes – contain pectin instead of cellulose
Diatoms – cell walls are rich in silicon
Dinoflagellates – half photosynthesize, half heterotrophic–Gonyolax – toxin causing red tides which causes paralytic shellfish poisoning when is makes humans sick
•
Fungus Like ProtistsFungus Like Protists
• Heterotrophs that decay organic matter
• Have centrioles but lack chitin unlike true fungi
Slime Molds – recycle organic matter
Water Molds – live on dead matter in water; some are plant parasites on land
• Phytophthora infestans – type of water mold that caused the Irish potato famine between 1845 and 1851