acidophiles (live at low pH) ◦ Archaea are more abundant and widespread than previously thought ▪ present in vast numbers in soil and in ocean ▪ associate with many animals ◦ Methanogens ▪ archaea that produce methane (natural gas)
▪ Obligate anaerobes (can only grow in environments that lack oxygen) ▪ Very abundant in the environment Eukaryote ◦ membrane bound nucleus ◦ can be unicellular, colonial, or multicellular ◦ reproduction is asexual or sexual ◦ many eukaryotes are microbial ◦ microbial protists ▪ any eukaryote that isn't animal, fungus, or plant ▪ Algea: photo-autotrophic protist ◦ disease causing protists ▪ Phytophthora infestans the plant destroyer, cause of late blight an oomycete cause of the irish potato famine ▪ Giardia lamblia (in intestines) ▪ Toxoplasma ghandi ◦ 6-8 main lineages of Eukaryotes ▪ Most are protists and all lineages contain at least some protists ◦ Fungi ▪ more closely related to animals than to the rest of the Eukaryotes ▪ Absorptive heterotrophs (absorb nutrients throughout cell membrane) often Saprobes that recycle organic material ▪ can be unicellular or multicellular Yeasts: single cells Filamentous Fungi: mycelial Dimorphic fungi: have both yeast and mycealial forms ▪ reproduce via spores ▪ important for biotechnology, food production, and disease ▪ Unicellular Fungi Saccharoyces cerevisiae: yeast used for bread and beer Candida albicans: yeast that can infect people with compromised immune systems ▪ Filamentous Fungi grows with chains of grows with a chains of cells called hyphae ◦ Ex: molds, and mildews, mushrooms ▪ disease fungi are a common cause of disease Ex: Chytrid fungi infects amphibians ◦ Microscopic animals ▪ Ex: dust mite, nematode worm, Platyhelminths worm Helminth worms are a major cause of disease in animas, including Humans Viruses ◦ Not truly “microorganisms” because they are not alive
◦ microscopic, infectious particles ◦ Bacteriophage: virus that infects bacteria ◦ extremely small (100 nanometers) ◦ initially called “filterable agents” ◦ structure and terminology ▪ Naked Virus a nucleic acid enclosed in a capsid (composed of capsomeres) Ex: bacteriophage, T4, Tobacco mosaic virus (first virus to be discovered) ▪ Enveloped Virus Capsid surrounded by a lipid bi-layer from a cell it infects Ex: herpes virus, pox virus (largest of all viruses) ◦ Virus Genome Diversity ▪ genome can be DNA (can be single or double stranded) or can have RNA (single or double stranded) ▪ Viruses require a living cell for replication (intraobligate) ▪ Lytic Virus: after reproduction, particles assemble inside the host, then exit to exterior (glycose) ▪ Temperate (Lysogenic) Viruses remain in latent state viral genome integrates DNA into host cell genome (called prophage) Host- Cell DNA polymerase copies chromosome cell divides (now called a lysogenic cell) can be induces to produce viral particles (lytic stage) such as temperature or pH stress ▪ Other possible outcomes
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- Bacteria, proton motive force, ex