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PROKARYOTES AND VIRUSES Eubacteria – Structure, Metabolism and Reproduction Archaea – Structure, Metabolism and Reproduction Viruses – Structure, Metabolism and Reproduction EUBACTERIA – STRUCTURE made of prokaryotic cells that include the following structures: capsule sticky outer coating that prevents water loss, resists high temperatures and controls entry to cells only found in some bacteria cell wall made of peptidoglycan cell membrane DNA large chromosome plasmid – small loop of DNA ribosomes pilli cytoskeleton projections on the outside of cell allow for conjugation flagellum cytoskeleton projections on the outside of cell allow for movement EUBACTERIA - STRUCTURES shapes, size and arrangement are variable three common shapes include: coccus bateria round shape bacillus bacteria rod shape spirillum bacteria spiral shape three common arrangements include: diplo arrangement bacteria that exist in pairs staphylo arrangement bacteria that exist in clumps strepto arrangement bacteria that exists in strings EUBACTERIA – METABOLISM metabolism varies between eubacteria can be classified by how they obtain nutrients autotrophic bacteria create their own food using inorganic substances heterotophic bacteria consume other organisms containing organic substances can be classified by their need for oxygen obligate aerobe bacteria require oxygen to break down food for energy facultative aerobe bacteria can use oxygen to break down food for energy (aerobic respiration and fermentation) can break down food without oxygen (anaerobic respiration and fermentation) obligate anaerobes cannot live in the presence of oxygen EUBACTERIA – REPRODUCTION reproduce asexually using binary fission 1. 2. 3. 4. 5. cell grows chromosomes duplicate cell grows cell divides into two cells daughter cells have the same genetic makeup as the parent cell EUBACTERIA – REPRODUCTION are able to exchange DNA or acquire new DNA from their environment to increase genetic diversity conjugation two eubacteria attach using their pilli a copy of a plasmid passes from one eubacteria to another http://www.youtube.com/watch?v=O-EdX4MaMFE&feature=related EUBACTERIA – REPRODUCTION transformation eubacteria pick up discarded DNA from their surroundings and incorporate this DNA into their chromosome if DNA comes from a different species this process is known as horizontal gene transfer http://www.youtube.com/watch?v=MRBdbKFisgI&feature=related EUBACTERIA – EXAMPLES Type Characteristics proteobacteria • most are photosynthetic • thought to be ancestors of mitochondria • cause many diseases • bubonic plague, gonorrhea, ulcers green bacteria • photosynthetic • found in salt-water and hot springs cyanobacteria • photosynthetic • thought to be ancestors of chloroplasts • found in aquatic ecosystems as producers and decomposers Picture EUBACTERIA – EXAMPLES Type Characteristics gram-positive bacteria • cause many diseases • strep throat, meningitis • used in food production • yogurt spirochetes • spiral shaped flagellum to move in a corkscrew pattern • cause syphilis chlamdias • parasites • cause chlamydia Picture ARCHAEA – STRUCTURE AND REPRODUCTION Structure made up of prokaryotic cells that include the following structures: cell wall with no peptidoglycan cell membrane DNA Reproduction reproduce asexually mechanism is unknown most likely similar to binary fission ARCHAEA – METABOLISM metabolism varies between archaea methanogens live in low-oxygen environments (swamps, marshes, digestive tracts of mammals and insects) use methane to generate energy halophiles live in high salt environments (Dead Sea, foods preserved by salting) use light and other organisms to generate energy extreme thermophiles live in hot environments (hot springs and hydrothermal vents) use heat energy to generate energy psychrophiles live in cold environments (Antarctic and Arctic oceans) mechanism to generate energy is unknown VIRUSES – STRUCTURE not made of cells non-living structures that include the following components: DNA or RNA viruses that contain DNA are called DNA viruses hepatitis B viruses that contain RNA are called RNA viruses HIV/AIDS capsid protein coat that surrounds the genetic material of the virus VIRUSES - STRUCTURE more complex viruses can also include: envelop created on the outside of a viruses when it leaves the host cell part of the host cell’s membrane sheath, plug and tail fibers found only in bacteriophages (phages) viruses that infect bacteria structure used to inject genetic material into the host VIRUSES – METABOLISM only active when they have infected a living cell do not perform any life functions on their own have no metabolic structures or systems VIRUSES – REPRODUCTION only active when they have infected a living cell 1. Virus infects host cell and inserts DNA/RNA into the host. 2. Viral DNA/RNA forms a loop. 3. DNA/RNA can be copied by inserting itself into the hosts chromosomes (lysogneic cycle). 4. DNA/RNA instructs cells to make new viral DNA/RNA and capsids (lytic cycle). 5. Newly formed viruses are released when the host cell burts (lytic cycle). http://www.youtube.com/watch?v=Rpj0emEGShQ
