The Eukaryotic Members of the Microbial World Chapter 12

12.1 Algae Engage in photosynthesis Fresh and salt water habitats Phytoplankton Structural composition Cell wall Nucleus Chloroplast Mitochondria

Toxins Algae do not infect animals However, many produce toxins Brevetoxin is associated with red tide Various shellfish toxins neurotoxins saxitoxin (dizziness, diarrhea and vomiting, disorientation, respiratory distress) gonyautoxins (paralysis) 12.1 Algae (cont.)

12.2 Protozoa Free-living single-celled organisms Highly motile Nutritional acquisition Decomposers Predators The largest genome belongs to a protozoan Amoeba dubia x nucleotides Highly motile Cilia Flagella Pseudopodia

Diseases caused by protozoa Toxoplasmosis (Toxoplasma gondii) Schizophrenia? African sleeping sickness (Trypanosoma sp.) Malaria (Plasmodium sp.) Amoebic dysentery Giardiasis (Giardia sp.) Leishmaniasis (Leishmania sp.) Cryptosporidiosis (Cryptosporidium sp.) 12.2 Protozoa (cont.)

12.3 Fungi Yeasts, molds and mushrooms Most are aerobes or facultative anaerobes Nutritional acquisition is primarily through absorption of dead organisms or organic matter Some exhibit dimorphism Exist as single-celled yeast, or... Multicellular organisms Some are fermenters

Diseases Fungal diseases are termed mycoses Mycoses are rare in immunocompetent people Topical or superficial mycoses are usually treatable Visceral mycoses are serious, often fatal Toxins Aflatoxins (Aspergillus sp.) are hepatotoxic (cancer) Halucinogenic mushrooms Amatoxin (mushrooms) inhibits RNA pol II Antibiotics Penicillin Griseofulvin (for athlete’s foot) 12.3 Fungi (cont.)

12.5 Multicellular Parasites: Arthropods and Helminths Arthropods Vectors for infectious diseases Mosquitos Ticks Fleas

12.5 Multicellular Parasites: Arthropods and Helminths (cont.)