C Lab 2 Homework and Handout SP17

Exercise 3-3: Examination of Eukaryotic Microbes Terms: Plastid : A double membrane bound organelle involved in the synthesis and storage of food that is commonly found within the cells of photosynthetic organisms like plants. Prokaryotes : A small, single-celled organism that lacks a nucleus (instead, it has circular, covalently-closed DNA within the cytoplasm) and other organelles. Its ribosomal components are similar, but somewhat smaller, than those of eukaryotes. Prokaryotes are more primitive than eukaryotes. Eukaryotes: A larger type of cell that contains organelles including a nucleus for its genetic material (DNA). Its DNA is organized in linear strands and often contains introns (intervening sequences). Ribosomal components are similar, but somewhat larger, than their prokaryotic counterparts. Domains: A broad classification of ALL organisms based on the sequence of nucleotides in rRNA. There are three domains: Bacteria and Archaea are two domains within the prokaryotes and Eukarya is the third domain which includes all eukaryotes. rRNA: Ribonucleic acid, the intermediary between genetic information (DNA) and enzymes (protein). That is, gene expression requires the copying of selective portions of DNA into RNA (which is called messenger RNA or mRNA). RNA can also be structural as in ribosomal RNA (rRNA), and it is vitally important in the translation of mRNA into proteins as transfer RNA Supergroups: Five divisions [six divisions in some schemes] of Eukarya that are larger than the classical Kingdoms. Endosymbiotic theory: The theory whereby a primitive prokaryote was engulfed (but not digested) by a larger prokaryote that led to the formation of eukaryotic cells. This theory is especially well accepted for the case of Archaeplastida where the modern-day chloroplasts of plants and red/green algae are most likely derived from an engulfed Trophozoite: Feeding stage in the life cycle of certain protozoans. Cyst: Resting (or dormant) stage in the life cycle of certain protozoans. Autotroph: An organism that fixes CO2 (generates large, complex organic molecules from CO2). Heterotroph: An organism that requires carbon in the form of organic molecules. Mixotroph: An organism that can live autotrophically (when light is available) or heterotrophically. Historically, Euglena is an important example. Pseudopods: “False feet” or extensions of cytoplasm from amoebae that are used for movement as well as engulfing prey. Amoebae are irregularly-shaped organisms that constantly change shape via the production of pseudopods. Cilia : Small filamentous organelles, like fibers, that are usually numerous whip-like flagella that are used for both locomotion and feeding

Saprophyte(s) : A heterotroph that digests dead organic matter (a decomposer). Parasite(s) : An organism that lives symbiotically with another, but to the detriment of the other organism (the host). Mold(s) : An informal grouping of filamentous fungi. Terms -3 Hypha(e) : A filament (or filaments) of fungal cells. Mycelium : A mass of fungal filaments (hyphae). Conidia : The asexual, non-motile spores of a fungus. They are the small spheres that appear at the ends of the fruiting bodies of both Aspergillus and Penicillium molds. Conidia are dispersed when they become airborne something like the seed heads of a mature dandelion. Yeast: An informal grouping of unicellular fungi.. Zygospore(s) : Product of fertilization and the site of meiosis in some molds. Biol 212 Exercise 3-3: Examination of Eukaryotic Microbes Fill in the blanks and answer questions: • Theory • Prokaryotes vs. Eukaryotes (Table 3-3) • Prokaryotes: two domains- ________ Archaea _ __________&_________ Bacteria _________ • Eukaryotes: one domain - Eukarya • Kingdoms: Plants, Animals, Protists & Fungi • Microscopic – Protists & Fungi • Protists (protozoans & algae) • Fungi (yeasts & molds) • Supergroup Excavata • Unicellular, feeding groove, one or more flagella • Typical lifecycle typically includes both trophozoite & cyst • Subgroup: Parabasalids a) Representative: 1. Trichomonas vaginalis Nucleus, Flagella, Undulating membrane, Hydrogenosomes Which sexually transmitted disease (STD) is cause by this organism? Trichomoniasis • Subgroup: Diplomonads a) Representative: 1. Giardia lamblia - trophozoite Mitosomes , Paired nuclei, Flagella (four pairs), Median bodies (2) In figure 3-13 Panel B can you see the four pairs of flagella? NO- and we don’t have any good slides in the lab.

Cilia, beaded macronucleus, cytosome, green (3) Balantidium coli - trophozoite (prepared slides) Identify cilia and macronucleus What are the symptoms of an acute infection cause by this organism? Acute infection: bloody, mucoid stool (diarrhea as often as every 20 minutes) Chronic infection: alternating diarrhea and constipation b) Apicomplexa Non-motile Complicated life cycles, with more than one host, affecting multiple tissues Representative: (1) Plasmodium falciparum (prepared slide) In humans it infects liver and RBCs; in mosquitoes it infects gut and salivary glands Identify human red blood cells and parasites. Find a red blood cell with the parasite on the inside of the cell. What disease does this organism cause in humans? Malaria • Subgroup: Stramenophiles (also spelled Stramenopiles) Most have a unique flagellum with three-parted lateral hairs a) Diatoms Lack flagella, aquatic, single celled or colonial autotrophs Fucoxanthin is a golden brown pigment, cell walls have two halves with one half overlapping the other Representative: (1) Diatoms – mixed species (prepared slide) Identify centric and pennate forms What inorganic compound gives a glass-like property to their cell walls? Silica (aka silicon dioxide, SiO 2 ) • Supergroup: Unikonta • Heterotrophs (amoebas, animals, fungi, and others) • Subgroup: Gymnamoebas • Representative: • (1) Amoeba proteus (prepared slide & live culture if available) • Identify nucleus & pseudopods • Subgroup: Entamoebas Representative: (1) Entamoeba histolytica - trophozoite (prepared slides) Identify nucleus Describe what the nucleus looks like: Ring around the nucleus (looks like a “bullseye” of a target) We didn’t look at this organism in lab because it is difficult to distinguish from the fecal material on the slide. What type of specimen is used to diagnose infections caused by this organism?

Stool (fecal) sample • • Subgroup: Fungi • a) Yeasts • Representatives: • (1) Saccharomyces cerevisiae (prepared slide) • Identify vegetative cells, nuclei, and budding cells Does this yeast cause diseases in humans? NO. S. cerevisiae is often called baker’s or brewer’s yeast because it is used in the making of bread, beer and wine . (2) Candida albicans (prepared slide) Identify vegetative cells and budding cells Define pseudohyphae: A chain of easily disrupted fungal cells that is intermediate between a chain of budding cells and a true hypha. Is this organism an opportunistic pathogen? Yes, C. albicans can cause thrush in the oral cavity, vulvovaginitis or cutaneous infection of skin. • b) Molds • Representatives: • (1) Rhizopus sp. (two prepared slides) • Identify asexual spores, sexual spore ( zygospore ) On what type of food is this genus of mold commonly found? Bread (2) Aspergillus sp. (prepared slide) Identify hyphae, conidia (asexual spores) What commercial products are manufactured using this organism? Soy paste and soy sauce from soybeans ( A. oryzae & A. soyae ) & Citric acid (Aspergillus niger) (3) Penicillium sp. (prepared slide) Identify hyphae, conidia (asexual spores) What food product is manufactured using this organism? Blue-veined cheeses (ex P. roquefortii and P. camemberti in Roquefort, Camembert and Brie) Sausage and ham (ex P. nalgiovense to improve flavor and to prevent colonization by other molds and bacteria)