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 Grano's hangout, Where I talk about whatever I want to.
granobulax
Posted: Mar 11 2009, 01:03 AM


He's even got his hand over where I live...


Group: Admin
Posts: 7,880
Member No.: 35
Joined: 31-May 08



QUOTE (Jailer411 @ Mar 11 2009, 12:34 AM)
QUOTE (treacherous @ Mar 10 2009, 04:04 PM)
QUOTE (Jailer411 @ Mar 10 2009, 09:40 PM)
QUOTE (Darkender @ Mar 10 2009, 03:37 PM)
QUOTE (Solomon @ Mar 10 2009, 04:29 PM)
QUOTE (Bassetman @ Mar 10 2009, 09:11 PM)
I miss Bob. He was my Wingy.

Yeah I miss him too. I really wish he'd come back.

Was that Sharpshooter?

Sharpshooter was bobthe4th.

How do you know that?

Surfer could probably get Shooter or TOAF over here, but they wouldn't stay long. Not unless they were promised another admin war against Nesh.

I try to keep myself from posting things like that. Questions start to come up.

Yes, yes they do... ninja.gif

Anyways, I had yet another clinical day today. I was able to do some good patient teaching and refine some of my paperwork. Boring, yet necessary.


--------------------
Points:


I scare little kids.
user posted image

QUOTE (treacherous @ Aug 16 2008, 12:12 PM)
RRRAOAAOAOAORRARRAA!!...  Blue lights and sirens rang through the night!! Yeah, they all wanna kill each other... HERE ME CITY!! THE STREETS BELONG TO THE GANGS NOW!! THIS IS THE NEW ORDER!! PREPARE FOR CHAOS!!

Solomon and I may be gangsta, but treach is the gangsta of the year!
Top
granobulax
Posted: Mar 12 2009, 12:48 AM


He's even got his hand over where I live...


Group: Admin
Posts: 7,880
Member No.: 35
Joined: 31-May 08



Take a look at the 3x5 notecard I made for my microbiology test. Keep in mind that I compressed all of this into font 3.5 and brought a magnifying glass to class with me to read.

Ch 11 Mutation A mutation is a heritable change in the base sequence of that genome. Genetic alterations can also be brought about by recombination, the physical exchange of DNA between genetic elements. Entire genes, sets of genes, or even larger segments of DNA can be transferred between chromosomes or other genetic elements. Prokaryotes don¡¦t reproduce sexually so they possess mechanisms of lateral genetic exchange that allow for both gene transfer and recombination. They employ a genetic mark to any gene whose presence is monitored during a genetics experiment. Induced mutation: natural mutation. Aleletarias mutation: harmful/ majority of mutations. Uncommon positive mutations. Genotype: changed but not expressed. Phenotype: Changed and expressed. Wild type strain: A strain isolated from nature. Changes are from wild type. Cystic fibrosis = common = 1 amino acid is incorrect. Selectable mutation confers a clear advantage on the mutant strain under certain environmental conditions, so the progeny of the mutant cell are able to outgrow and replace the parent. A good example of a selectable mutation is drug resistance: an antibiotic-resistant mutant can grow in the presence of antibiotic concentrations that inhibit or kill the parent and is thus selected for under these conditions. Selection is therefore an extremely powerful genetic tool, allowing the isolation of a single mutant from a population containing millions or even billions of parental organisms. Induced mutation:: are those that are made deliberately. Spontaneous mutation: Those that occur without human intervention. Can occur with contact with natural radiation (cosmic rays and so on) that alters the structure of bases in the DNA. Also, oxygen radicals can affect DNA structure by chemically modifying DNA. The bulk of spontaneous mutations result from errors in the pairing of bases during DNA replication. Point modifications: change only one base pair. They¡¦re caused by base-pair substitutions in the DNA or by the loss or gain of a single base pair. As is the case with all mutations, the phenotypic change that results from a point mutation depends on exactly there the mutation occurs in the gene, what the nucleotide change is, and what product the gene encodes. Missense mutation: The information ¡§sense¡¨ (precise sequence of amino acids) in the ensuing polypeptide has changed. Changes in the first or second base of the triplet more often lead to significant changes in the polypeptide. For instance, a single-vase change from UAC to AAC results in an amino acid change within the polypeptide from tyrosine to asparagines at the specific site. TAC/ATG could be AAC/TTG „³ AAC Asparagine codon „³ faulty protein; Missence mutation, TAG/ATC „³ UAG Stop codon „³ incomplete protein; Nonsense mutation, TAT/ATA „³ UAU Tyrosine codon „³ Normal protein; Silent mutation, or TAC/ATG „³ Tyrosine codon „³ Normal protein; Wild type. Nonsense mutations: Results in premature termination of translation, leading to an incomplete polypeptide that would almost certainly not be functional. Frameshift; Insertion adds a base in a codon to shift the code sequence in a gene. Deletion simply takes a base away, effectively shifting the sequence in similar fashion. Spontaneous mutations are from DNA replication. Mutation rate in RNA genomes is about 1,000-fold higher than in DNA genomes. UV radiation = non-ionizing. X-ray and gamma = penetrating radiation (high energy). Transformation: a genetic transfer process by which free DNA is incorporated into a recipient cell and brings about genetic change. Competent bacteria can pick up dead bacteria. Mechanism of transformation in a gram-positive bacterium: a) Binding of double-stranded DNA by a membrane-bound DNA-binding protein. B Passage of one of the two strands into the cell while nuclease activity degrades the other strand. C) The single strand in the cell is bound by specific proteins, and recombination with homologous regions of the bacterial chromosome is mediated by RecA protein. D) Transformed cell. Transduction: A bacterial virus (bacteriophage) transfers DNA from one cell to another. Viruses can transfer host genes in two ways. In the first, called generalized transduction, DNA derived from virtually any portion of the host genome is [packaged inside the mature virion in place of the virus genome. Ch 15 Purple phototropic bacteria: Key genera: Chromatium, ectothiorhodospira, phrodobacter, phodospirillum. Carry out anoxygenic photosynthesis. Unlike cyanobacteria no O2 is released. Contain bacterioclorophylls and carotenoid pigments. These pigments give purple bacteria their purple, red and brown colors. Produce intracytoplasmic photosynthetic membrane systems. Purple sulfur bacteria: Utilize hydrogen sulfide (H2S) as an electron donor for CO2 reduction in photosynthesis. The sulfide is oxidized to elemental sulfur that is stored in globules inside the cells. Usually found in illuminated anoxic zones of lakes and other aquatic habitats where H2S accumulates and also in sulfur springs. Nitrifying Bacteria: Chemolithotropic bacteria are physiologically united by their ability to utilize inorganic electron donors as energy sources gaining energy from the process. Many are also capable of autotrophic growth and share a major physiological trait with phototrophic bacteria and cyanobacteria. Nobody oxidizes both ammonia and nitrates. Nitrifying bacteria are widespread in soil and water. They live in habitats where considerable amounts of ammonia are present such as decomposition and sewage treatment facilities or lakes and streams where sewage dumps into the water. Sulfur andiron-oxidizing bacteria: Able to grow chemolithotrophically on reduced sulfer compounds. Two classes; living at neutral pH and acidic pH. Some grow chemolithotrophically using ferrous iron as an electron donor. Some are acidophilic. Hydrogen Oxidizing bacteria: Grow with H2 as sole electron donor and O2 as electron acceptor using ¡§knallgas¡¨ reaction, the reduction of O2 with H2 as their energy metabolism. Makes water. Most can grow autotrophically using reactions of the Calvin cycle to incorporate CO2. Grow best under microoxic conditions because hydrogenases are typically oxygen sensitive. Nickel must be present in medium because all hydrogenases contain Ni2 as key metal cofactor. Some can grow on carbon monoxide as electron donor. Cooxidizing bacteria called carboxydotrophic bacteria grow autotrophically using the Calvin cycle. CO2 consumption by carboxydotrophic bacteria in nature is a significant ecological process to reduce CO2 in atmosphere. Methanotrophs and Methylotrophs Methane is found in anoxic muds, marches, anoxic zones of lakes, the rumen, and the mammalian intestinal tract. Utilize methane as electron donors. All aerobes available in soil and water. 2 step breakdown process. Common in decomposition one carbon compounds. Widespread in aquatic and terrestrial environments. Methanotrophs are often concentrated in a narrow band at the zone where methane and oxygen meet. Methanotrophs and nitrosifying bacteria: Methanotrophs are able to oxidize ammonia although they cannot grow chemolithotrophically using ammonia as sole electron donor. In addition to methane oxidation, methane monooxytenase also functions to oxidize ammonia. Ammonia is generally toxic to methanotrophs and the preferred nitrogen source is nitrate. Methanotrophic bacteria and certain marine mussels and sponges develop symbiotic relationships. Some marine mussels live in the vicinity of hydrocarbon seeps on the seafloor, places where methane is released in substantial amounts. Isolated mussel gill tissues consume methane at high rates in the presence of O2. The symbionts are bound in vacuoles within animal cells near the gill surface, which probably ensures an effective gas exchange with seawater. Pseudomonas and Pseudomonads: Straight or slightly curved chemoorganotrophic aerobic rods with polar flagella. A plant pathogen that is responsible for a number of necrotic plant lesions and that is characterized by its yellow colored pigments. Characteristics of pseudomonads: very simple nutritional requirements. Striking properties of pseudomonads is their use many different organic compounds as carbon and energy sources. Utilize over 100 different compounds and only a few species utilize fewer than 20. Straight or curved rods but not vibroid; size 0.5-1.0 u.m. by 1.5-4.0 u.m. no spores; gram negative; polar flagella- single or multiple; no sheaths, appendages, or buds; respiratory metabolism, never fermentative, although may produce small amounts of acid from glucose aerobically; use low-molecular weight organic compounds, not polymers; some are chemolithotrophic, using H2 or CO as sole electron donor; some can use nitrate as electron acceptor anaerobically; some can use arginine as energy source anaerobically. Ecologically important organisms in soil and water and are probably responsible for the degradation of many soluble compounds derived from the breakdown of plant and animal materials in oxic habitats. They are also capable of breaking down many xenobiotic (not naturally occurring) compounds, such as pesticides and other toxic chemicals and are thus important agents of bioremediation in the environment. Most pseudomonads metabolize glucose. A number of pseudomonads are pathogenic. Frequently associated with infections of the urinary and respiratory tracts in humans. The organism is an opportunist, initiating infections in individuals whose resistance is low. It can also cause systemic infections, usually in individuals who have experienced extensive skin damage. Other pseudomonads are also human pathogens. Can infect the lungs of patients with cystic fibrosis. Naturally resistant to many widely used antibiotics. Free-living aerobic nitrogen-fixing bacteria: A variety of organisms inhabit soil and are capable of living N2 aerobically. The genus Azotobacter comprises large, gram-negative, obligately aerobic rods capable of fixing N2 nonsymbiotically. Phylogenetically, most free-living nitrogen-fixing bacteria. Azotobacter is able to grow on many different carbohydrates, alcohols, and organic acids. The metabolism of carbon compounds is strictly oxidative, and acids or other fermentation products are rarely produced. All members fix nitrogen but can also grow on simple forms of combined nitrogen; ammonia, urea, and nitrate. Azotobacter can form resting structures called cysts show negligible endogenous respiration and are resistant to desiccation, mechanical disintegration, and ultraviolet and ionizing radiation. Cysts are not especially heat-resistant, and they are not completely dormant because they rapidly oxidize carbon sources if supplied. Enteric bacteria: Comprise a relatively homo generous phylognetic group within the Gammaproteobacteria and consist of facultatively aerobic, gram-negative, nonsporulating rods that are either nonmotile or motile by peritrichous flagella. Enteric bacteria are also oxidase-negative, have relatively simple nutritional requirements, and ferment sugars to a variety of end products. Many species pathogenic to humans, other animals, or plants, as well as other species of industrial importance. Fermentation patterns in Enteric Bacteria: One important taxonomic characteristic separating the various genera of enteric bacteria is the type and proportion of fermentation products produced by anaerobic fermentation of glucose. Salmonella and Escherichia are quite closely related, the two genera. In contrast to most Escherichia, members of the genus Salmonella are usually pathogenic, either to humans or to other warm-blooded animals. Most common diseases caused by salmonellas are typhoid fever and gastroenteritis. Shigellas are also genetically very closely related to Escherichia. Tests for DNA hybridization show that strains of Shigella have 70% or even higher genomic hybridization with E. coli and therefore probably form a single species. Shigella is commonly pathogenic to humans, causing a rather severe gastroenteritis. Shigella dysenteriae is transmitted by food and waterborne routes and is capable of invading intestinal epithelial cells. Proteus is characterized by rapid motility. Frequent cause of urinary tract infections in humans and probably benefits in this regard from its ready ability to degrade urea. Bibrio, Aliivibrio, and Photobacterium: The Vibrio group, family Vibrionaceae, contains gram-negative facultatevely aerobic rods and curved rods that possess a fermentative metabolism. Most vibrios and related bacteria are aquatic, found in marine, brackish, or freshwater habitats. Vibrio cholera is the specific cause of the disease cholera in humans. The organism does not normally cause disease in other hosts. Cholera is one of the most common infectious human diseases in underdeveloped countries. Transmitted almost exclusively via water. Bacterial Bioluminescence, several species of bacteria can emit light. Rickettsias: Are small, gram-negative, coccoid or rod-shaped proteobacteria. They are, with one exception, obligate intracellular parasites and have not yet been cultivate in the absence of host cells. Rickettsias are the causative agents of several human diseases, including typhus (any one of several similar diseases caused by louseborne bacteria), rocky mountain spotted fever, and Q fever. Metabolism and Pathogenesis: They can oxidize only glutamate or glutamine and cannot oxidize glucose or organic acids. Able to synthesize at least some of the small molecules needed for macromolecular synthesis and growth, and they obtain the rest of their nutrients from the host cell. Do not survive long outside their hosts. They must be transmitted from animal to animal by arthropod vectors. Can also be transmitted to the respiratory system by aerosols. C. burnetti is the most resistant of the rickettsias to physicals damage, probably because it produces a resistant, sporelike form. Spirilla are gram-negative, motile, spiral-shaped Proteobacteria that show a wide variety of physiological attributes. Some of the key taxonomic criteria used are cell shape, sixe, number of polar flagellation (single or multiple), relation to oxygen (obligatley aerobic, microaerophilic, facultative), relationship to plans (as symbionts or plant pathogens) or animals (as pathogens), fermentative ability, and certain other physiological characteristics (for example, nitrogen-fixing ability, halophilic nature, thermophilic nature). Magnetic spirilla: highly motile microaeropilic magnetic spirilla have been isolated form freshwater habitats. Within the cells are chains of 5-40 magnetic particles called magnetosomes. Sulfate- and Sulfur- Reducing Proteobacteria: Sulfate and sulfur are electron acceptors for a large group of anaerobic Deltaproteobacteria that utilize organic compounds or H2 as electron donors. Hydrogen sulfide is the product of both sulfate and sulfur reduction. Over 40 genera of these organisms, collectively called the dissimilative sulfate-reducing bacteria and sulfur-reducing bacteria. Use of sulfate or sulfur as electron acceptors in energy generation instead of their assimilation as biosynthetic sources of sulfur. General properties: Utilize lactate, pyruvate, ethanol, or certain fatty acids as electron donors, reducing sulfate to hydrogen sulfide; they are unable to catablolize acetate. Specialize in the oxidation of fatty acids, particularly acetate, reducing sulfate to sulfide. Obligate anaerobes, and strict anoxic techniques must be used in their cultivation. Widespread in aquatic and terrestrial environments that become anoxic as a result of microbial decomposition process. Phylogenetically a member of the gram-positive Bacteria, consists of endospore-forming rods found primarily in soil. Growth and reduction of sulfate by Desulfotomaculum in certain canned foods leads to a type of spoilage called sulfide stinker. The Eplilonproteobacteria, the fifth class of proteobacteria, was initially defined by certain pathogenic bacteria, in particular Campylobacter and Helicobacter. However, environmental studies of marine and terrestrial habitats have shown that a diversity of Epsilonproteobacteria can be found in a variety of habitats in nature, where their numbers and metabolic capabilities suggest they play important ecological roles. Are especially abundant at oxic-anoxic interfaces in sulfur-rich environments, such as around hydrothermal vents, where they catalyze metabolic transformations of sulfur and lice in association with animals that live in these vent areas. Many of these bacteria are autotrophs and use H2, formate, asulfide, or thiosulphate as electron donor, with nitrite, oxygen, or elemental sulfur as electron acceptor, depending on the species. Campylobacter and Helicobacter: Although they represent separate families in this class, campylobacteraceae and Helicobacteraceae, they share a number of characteristics. They are all gram-negative, motile spirilla, and most species are pathogenic to humans or other animals. Campylobacter and Helicobacter species are also microaeropilic an are therefore cultured from clinical specimens in media incubated at low O2 and high CO2. Campylobacter species, over a dozen of which have been described, cause acute enteritis leading to (usually) bloody diarrhea, and pathogenesis is due to several factors, including an enterotoxin that is related to cholera toxin. Helicobacter pylori, also a pathogen, causes both chronic and acute gastritis, leading to the formation of peptic ulcers. Ch 16 Nonsporulating Gram-positive Bacteria: Called the Firmicutes and is composed of the lactic acid bacteria, which are classical nonsporulating gram-positive rods and cocci. Staphylococcus and Micrococcus: Both aerobic organisms with a typical respiratory metabolism. They are catalase-positive. Relatively resistant to reduced water potential and tolerate drying and high salt fairly well. Many species are pigmented. Micrococcus is and obligate aerobe and produces acid from glucose only under aerobic conditions, whereas Staphylococcus is a facultative aerobe and produces acid from glucose both aerobically and anaerobically, Staphylococcus also typically forms cell clusters. Staph are common commensals and parasites of humans and animals, and they occasionally cause serious infections. In humans, there are two major species, Staphylococcus epidermidis, a nonpigmented, nonpathogenic organism usually found on the skin or mucous membranes, and Staphylococcus aureus, a yellow pigmented species that is most commonly associated with pathological conditions, including boils, pimples, pneumonia, osteomyelitis, meningitis, and arthritis. The lactic acid Bacteria are gram-positive rods and cocci that produce lactic acid as a major or sole fermentation product. Members of this group lack porphyrins and cytochromes, do not carry out oxidative phosphorylation, and hence obtain energy only by substrate level phosphorylation. Grow anaerobically. Not sensitive to O2 and can grow in its presence. Thus called aerotolerant anaerobes. Obtain energy only from the metabolism of sugars. Limited biosynthetic abilities. Complex nutritional requirements include needs for amino acids, vitamins, purines, and pyrimidines. Streptococcus and other Cocci: quite distinct habitats and activities. Some species are pathogenic to humans and animals. Important roles in the production of buttermilk, silage, and other fermented products. Two genera are recognized. The genus Lactococcus contains those streptococci of dairy significance, whereas the genus Enterococcus includes streptococci that are primary of fecal origin. Lactobacillus: Rod-shaped, varying from long and slender to short, bent rods. Most species are homofermentative, but some are heterofermentative. Common in dairy products, and some strains are used in the preparation fo fermented milk products. Acidophilus mild, yogurt, sauerkraut, silage and pickles. More resistant to acidic conditions that are the other lactic acid bacteria. Able to grow well at pH values as low as 4. Acid resistance enables them to continue growing during natural lactic fermentations, even when the pH value has dropped too low for other lactic acid bacteria to grow. Responsible for the final stages of most lactic acid fermentations. They are rarely, ff ever, pathogenic. Listeria: requires microoxic or fully oxic conditions for growth and produces catalase. Causes a foodborne illness. Transmitted in contaminated, usually read-to-eat, foods. Can cause anything from a mild illness to a fatal form of meningitis. Endospore-forming Gram-Positive Bacteria: Bacillus, species of which are aerobic or facultatively aerobic. Bacillus: produce extracellular hydrolytic enzymes. Produce antibiotics, including bacitracin, polymyxin, tyroxidin, gramicidin, and circulin. Antibiotics are released during sporulation. Produce insect larvicides. Causes a fetal condition called milky disease in Japanese beetle larvae and larvae of closely related beetles. Causes a fatal disease of larvae of many different groups of insects, although individual strains are specific as to the host affected. Endospore preparations derived are commercially available as biological insecticides. Clostridium: lack a respiratory chain. Obtain ATP only by substrate level phosphorylation. Many anaerobic energy yielding mechanisms are known. Separation of the genus into subgroups is based primarily on these properties and on the fermentable substrate used. Main habitat is soil, where they live primarily in anoxic ¡§pockets,¡¨ made anoxic by facultative organisms metabolizing organic compounds. Inhabit the anoxic environment of the mammalian intestinal tract. Capable of causing severe disease in humans under specialized conditions. Both sugar and amino acid fermenters. Produce specific toxins or in those causing gas gangrene, a group of toxins. Can also cause gastroenteritis in humans and domestic animals. A major unsolved ecological problem is what role these extremely powerful toxins play in soil, the natural habitat of the organism. Cell Wall-less Gram-positive Bacteria: the Mycoplamas: they lack cell walls and are one of the smallest organisms capable of autonomous growth. Properties of Mycoplasmas: more resistant to osmotic lysis. Able to survive conditions under which protoplasts lyse. The presence of sterols. Plasmic membranes of mycoplasmas more stable than that of other bacteria. Growth of Mycoplasmas: Cells are small and pleomorphic. Small coccoid elements, larger, swollen forms, and filamentous forms of variable lengths, often highly branched. The minimum reproductive unit of 0.2-0.3 um probably represents the smallest free-living cell. The genomes of mycoplasmas are also smaller than those of most bacteria, between 500 and 1,100 kbp of DNA in most cases. This is comparable to the genome size of the obligately parasitic Chlamydia and rickettsia and about one-fifth or one-fourth that of Escherichia coli. Corynebacteria: Gram-positive, aerobic, non-motile, rod-shaped. Forming irregular-shaped, club-shaped, or V-shaped cell arrangements during normal growth. V-shaped cell groups arise as a result o snapping division. The genus Corynebacterium consists of an extremely diverse group of bacteria, including animal and plant pathogens and saprophytes. Some species are pathogenic. Characteristics of Mycobacteria: Somewhat pleomorphic and may undergo branching or filamentous growth. Become fragmented into rods or coccoid elements upon slight disturbance. Can be separated into two major groups, slow growers and fast growers. Form tight, compact, often wrinkled colonies. Hydrophobic nature of the cell surface that make cells stick together. Simple nutritional requirements. Growth in cords reflects the presence of a characteristic glycolipid, the cord factor, on the cell surface. Filamentous Actinobacteria: Streptomyces and relatives- Filamentous, gram-positive Bacteria that form branching filaments. Form spores. Spore-forming habit is of both phylogenetic and taxonomic importance. Over 500 species of Streptomyces are recognized. Are of indefinite length and often lack cross-walls in the vegetative phase. Grow at the tips of the filaments. Vegetative phase consists of complex, tightly woven matrix. As colony ages, sporophores are formed, which project above the surface of the colony and give rise to spores. Differences in the shape and arrangement of aerial filaments are used in classifying the streptomyces species. Ecology and isolation of streptomyces: a few can be found in aquatic habitats, mostly in soil. Earthy odor caused by metabolites called geosmins. Alkaline to neutral soils are favorable over acid soils. More are found in well drained soil such as sandy loams or soils covering limestone where conditions are more likely to be aerobic. Antibiotics of streptomyces: Adjacent colonies of other bacteria show zones of inhibition on agar plates. Over 500 distinct antibiotics made. Many genes are required to encode the enzymes for antibiotic synthesis. The genomes of streptomyces are quite large. Cyanobacteria and prochlorophytes: Cyanobacteria comprise a large morphologically and ecologically heterogeneous group of phototrophic bacteria. Are oxygenic phototrophs. Represent one of the major phyla of bacteria. Shows a distinct relationship to gram-positive bacteria. First oxygen evolving phototrophic organisms on earth. Responsible for the conversion of the atmosphere of the earth fro anoxic to oxic. Structure: Both unicellular and filamentous forms are known. Can be divided into five morphological groups; unicellular, dividing by binary fission. Unicellular, deciding by multiple fission. Filamentous, containing differentiated cells that function in nitrogen fixation. Filamentous nonheterocystous forms, and branching filamentous species. Cell wall similar to gram-negative bacteria and peptidoglycan is present in the walls. Many produce sheaths that bind groups together. The photosynthetic membrane system is complex and multilayered. All have phycobilins accessory pigments in photosynthesis. Can produce a blue-green color or red and brown.. Structural variations; gas vesicles and heterocysts- Common in species that live in open waters. The function of gas vesicles is to regulate cell buoyancy to remain in optimum photosynthesis. Some form heterocysts which are rounded and usually enlarged cells distributed regularly along a filament. Heterocysts arise from differentiation of vegetative cells . Sole sites of nitrogen fixation in heterocystous cyanobacteria. Heterocysts have intercellular connections with adjacent vegative cells to heterocysts. Lack photosystem II. Fixed carbon imported to the heterocysts for an adjacent vegetative cell solves the problem. Surrounded by a thickened cell wall. Contains large amounts of glycolipid. Maintains an anoxic environment. Ecology: Widely distributed in terrestrial, freshwater, and marine habitats. More tolerant of environmental extremes. Often the dominant or sole oxygenic phototrophic organisms in hot springs, saline lakes, and other extreme environments. Found on the surfaces of rocks or soil and occasionally even within rocks. Desert soils they form extensive crusts during most of the year and growing during the winter and spring rains. Shallow marine bays where warm seawater temperatures they create mats of considerable thickness. Freshwater lakes they develop blooms. Chlamydia: obligatetly parasitic bacteria with poor metabolic capacities. Chlamydophila psittaci, the causative agent of the disease psittacosis. Chlamydia trachomatis, the causative agent of trachoma. Chlamydophila pneumonia, the cause of respiratory syndromes. Molecular and metabolic properties: Chlamydias are intriguing because of the biological, evolutionary and metabolic problems they pose. Gram-negative-type cell walls, have both DNA and RNA. Dividing by binary fission. Biosynthetic capacities of the chlamydias are much more limited than even the rickettsias. Green sulfur bacteria are a phylognetically distinct group of nonmotile anoxygenic phototrophic bacteria that contain only obligately anaerobic and phototrophic species among cultured isolates. Morphologically restricted and includes short to long rods. Spirochetes are gram-negative, motile, tightly coiled bacteria. Slender and flexuous in shape. Morphologically unique. Widespread in aquatic environments and in animals. Some cause diseases, including syphilis. Made up of a protoplasmic cylinder, consisting of the regions enclosed by the cell wall and cytoplasmic membrane. Motility is conferred by single to many flagella the emerge from each pose. Flagella fold back from each pole on to the protoplasmic cylinder and remain located in the periplasm of the cell. Have also been called endoflagella. Surrounded by a multilayered but flexible membrane called the outer sheath. Motility: endoflagellum anchored at one end and extends about two-thirds of the length of the cell. The protoplasmic cylinder rotates in the opposite direction, placing torsion on the cell. Move by flexing or lashing motions due to torque exerted at the ends of the protoplasmic cylinder. Treponema: anaerobic host-associated spirochetes. Treponoma pallidum, the causal agent of syphilis is the best known species of Treponema. It differs in morphology form other spirochetes as it¡¦s flat and wavy. T. pallidum cell is remarkably thin. T. pallidum appears restricted to humans. Are microaerophiles. Treponema denticola is a major oral treponeme, ferments amino acids. Borrelia: majority of Borrelia are animal or human pathogens. Borrelia reurrentis is the causative agent of relapsing fever in humans, transmitted via an insect vector by the human body louse. Sensitive to tetracycline. Other species case diseases in cattle, sheep, horses, and birds. Most transmitted by ticks. Borrelia burgdorferi is the causative agent, tickborne disease called Lyme disease. B burgdorferi, one of the few known bacteria the has a linear chromosome. Leptospira and leptonema: strictly aerobic spirochetes that use long chain fatty acids as electron donor and carbon sources. Only substrates utilized by leptospiras for growth. Leptospira cells is thin, finely coiled, and usually bent at each end into a semicircular hook. Major species are Leptospira interrogans and Leptospira biflexa. L. interrigans are parasitic for humans and animals. In humans the most common leptospiral syndrome is leptosirosis. Leptospiras ordinarily enter the body through the mucous membranes or through breaks in the skin. Ch 17 Phylogenetic overview of archaea: A phylogenetic tree of Archaea based on sequence of 16S rRNA genes, reveals a major evolutionary split of Archaea into two groups. The Crenarchaeota and the Euryarchaeota. Crenarchaeota: contain mostly hyperthermophiles whose growth temperature optimum is greater than 80 degrees C ¡V including those able to grow at the highest temperatures of all known organisms. Several nonthermophilic a. Many hyperthermophiles are chemolithotrophic autotrophs. Are the sole primary producers in these habitats. Crenarchaeota tend to cluster closely together. Cold dwelling relatives have been identified by community analysis of rRNA genes. Euryarchaeota: Physiologically diverse group. Many inhabit extreme environments of one kind or the other. Includes methanogens and several extremely halophilic archaea, the ¡§halobacteria¡¨. Methanogens are the strictest of anaerobes while extreme halophile are obligate aerobes. Other groups include hyperthermophiles Thermococcus and Pyrococcus and the methanogen Methanopyrus and the cell wall-less Thermoplasma (similar to mycoplasmas). A large group yet uncultured euryarchaeotes exists in the marine environment. Many euryarchaeotes inhabit freshwater and terrestrial habitats. Energy conservation and autotrophy in Archaea: Energy metabolism in methanogens is unlike that of any other microbial group. Chemoorganotrophy and chemolithotrophy in Archaea: Several Archaea are chemoorganotrophic and thus use organic compounds as electron donors for energy metabolism. Catabolism of glucose in Archaea proceeds via slight modifications of Entner-Doudoroff or glycolytic pathways. Oxidation of acetate to CO2 in Archaea proceeds through the citric acid cycle or by the acetyl-CoA pathway. There are electron transport chains including cytochromes of the a, b, and c types in some archaea. Employing these and other electron carriers, chemoorganotrophic metabolism in most Archaea proceeds by introduction of electrons from organic electron donors into an electron transport chain, leading o the reduction of O2,S, or some other electron acceptor. Electron-transport reactions drive thy synthesis of a proton motive force that couples to ATP synthesis through membrane bound ATVases. Chemolithotrophy is also well established in the Archaea. Autotrophy in Archaea: Autotrophy is widespread in the Archaea and proceeds by several different pathways. Many of the catabolic and anabolic pathways in the Achaea are similar to those in bacteria. Extremely halophilic Archaea: sometimes called haloarchaea, are a diverse group of prokaryotes. Inhabits natural environments high in salt, such as solar salt evaporation ponds and salt lakes, or artificial saline habitats such as the surfaces of heavily salted foods. Salt habitats are called hypersaline. Extreme halophile is used to indicate that these organisms are not only halophilic, but that their requirements for salt is very high. Considered an extreme halophile if it requires at least 1.5 M NaCl for growth. Most require 2-4 M NaCl for optimal growth. Hypersaline environments: Chemistry and productivity: Extremely hypersaline habitats are rare. soda lakes are highly alkaline hypersaline environments. The diverse chemistries of hypersaline habitats has selected for a large diversity of halophilic microorganisms. Marine salterns are also habitats for extreme halophiles. Marine salterns are small, enclosed basins filled with seawater that are left to evaporate, yielding solar sea salt. Taxonomy and physiology: Stain gram-negatively, reproduce by binary fission, and do not form resting stages or spores. Most halobacteria are nonmotile. Plasmids from extreme halophiles are among the largest naturally occurring plasmids known and might actually be small chromosomes. Most species of extremely halophilic Archaea are obligate aerobes. Water balance in extreme Halophiles: Require large amounts of sodium for growth, typically supplied as Na Cl. Compatible solutes counteract the tendency of the cell to become dehydrated under conditions of high osmotic strength by placing the cell in positive water balance with its surroundings. Bacteriorhodopsin and light-mediated ATP synthesis in halobacteria: Certain species of haloarchaea can carry out a light driven synthesis of ATP. This occurs without chlorophyll pigments, so it is not photosynthesis. Other light-sensitive pigments are present, including red and orange carotenoids¡Xprimarily C50 pigments called bacterioruberins¡Xand inducible pigments involved in energy conservation. Methane producing Archaea: Methanogens- produce methane (CH4) as an integral part of their energy metabolism. Methane production is called methanogenesis. Diversity and physiology: Show a variety of morphologies. Taxonomy is based on both phenotypic and phylogenetic analyses, with several taxonomic orders being recognized. Substrates: Eleven substrates can be converted to methane by pure culture of methanogens. Do not include such common compounds as glucose and organic or fatty acids. Glucose can be converted to methane, but only in reactions in which methanogens and other anaerobic bacteria cooperate. With the right mixture of organisms, virtually any organic compound, even hydrocarbons, can be converted to methane plus CO2. Thermoplasmatales: a phylogenetically distinct line of Archaea contains thermophilic and extremely acidophilic genera: Thermoplasma, Ferroplasma, and Picrophilus. Among the most acidophilic of all known microorganisms with picrophilus being capable of growth even below pH 0. Archaea lacking cell walls: To survive the osmotic stresses of life without a cell wall and to withstand the dual environmental extremes of low pH and high temperature, Thermoplasma has evolved a unique cytoplasmic membrane structure. The membrane contains a lipopolysaccharide-like material called lipoglycan. This substance consists of a tetraether lipid monolayer membrane with mannose and glucose. Nanoarchaeum and aciduliprofundum: Nanoarchaeum equitans is one of the smallest cellular organisms with one of the smallest genomes of any cell, it lives as an obligate symbiont of the crenarchaeote Ignicoccus. They cannot grow in pure culture and replicate only when attached to the surface of Ignicoccus cells in the densities up to 10 or more cells per Ignicoccus cell. Whether Nanoarchaeum cells act as a parasite of it¡¦s host is not yet known. N. equitans and its host Ignicoccus were first isolated from a submarine hydrothermal vent off the coast of Iceland. The metabolism of Nanoarchaeum is not yet well understood but it appears to depend on its host for many of its metabolic functions; Ignicoccus is an autotroph that uses H2 as electron donor and S as electron acceptor. Habitats and energy metabolism of Crenarchaeota: Most hyperthermophilic archaea have been isolated from geothermally heated soils or waters containing elemental sulfur and sulfides and most species metabolize sulfur in one way or another. Mildly to extreme acidic owing to the production of sulfuric acid. Got sulfur rich environments called solfataras, are found throughout the world. Solfataras can be mildly acidic to slightly alkaline or extremely acidic with pH values below 1. Hyperthermophilic crenarchaeotes have been obtained from both acidic and alkaline environments, but the majority of these organisms inhabit neutral or mildly acidic hot habitats. Hyperthermophilic Crenarchaeota also inhabit hydrothermal vents. All hyperthermophiles with growth temperature optima above 100 degrees C have come from submarine sources. Deep hydrothermal vents are the hottest habitants so far known to yield prokaryotes. Energy metabolism: hyperthermophilic Crenarchaota are obligate anaerobes. Their energy-yielding metabolism is either chemoorganotrophic or chemolithotrophic and is dependent of diverse electron donors and acceptors, Fermentation sin rare, and most bioenergetic strategies involve anaerobic respirations. Electron transfer within the cytoplasmic membrane leading to the formation of a proton motive force from which ATP is made by way of proton translocating ATPases. Grow chemolithotrophically under anoxic conditions. Hyperthermophiles from terrestrial volcanic habitats: Terrestrial volcanic habitats can have temperatures are high as 100 degrees C and are thus suitable for hyperthermophilic archaea. Hyperthermophiles from submarine volcanic habitats: We now turn to the microbiology of submarine volcanic habitats, homes to the most thermophilic of all known Archaea. Nonthermophilic Crenarchaeota: have been identified from community sampling of SSU rRNA genes from many cool or cold marine and terrestrial environments. Microbiologists have found crenarchaeotes in oxic marine waters worldwide. Marine crenarchaeotes thrive even in frigid waters and sea ice, such as those near Antarctica. These organisms are planktonic and presents in significant numbers in waters that are both nutrient poor and very cold. Marine crenarchaeotes can account for up to 40% of the prokaryotes of deep ocean waters. They contain ether-linked lipids, the hallmark of the Archaea. Crenarchaeota play a major role in the global carbon cycle. Nonthermophilic species of Euryarchaeota are also present in marine environments. Nitrification in archaea: a crenarchaeota named Nirosopumilus maritimus was isolated from a saltwater aquarium and shown to grow chemolithotrophically by aerobically oxidizing ammonia to nitrate, the first demonstration of nitrification in Archaea. Stability of Monomers: at temperatures as low as 120 degrees C, some important small molecules are destroyed at significant rates. ATP and NAD hydrolyse rapidly at these temperatures; the half-life of ATP or NAD in vitro is less than 30 minutes at 120 degrees C and shortens dramatically at temperatures above this. The high concentrations of cytoplasmic solutes, such as salts, sugars, and other small molecules, likely have a protective effect on ATP and other key molecules. More heat-stable molecules might replace the function of certain of these compounds. Protein folding and thermostability: Most proteins denature at high temperatures. For increased levels of amino acids that form alpha helices, which may help stabilize these proteins. Enzymes from hyperthermophiles contain the same major structural features; as their heat labile counterparts form mesophilic bacteria. Thermostable proteins typically do display some structural features that improve their thermostability. These include highly hydrophobic cores, which decrease the tendency of the protein to unfold in an ionic environment. More ionic interactions on the protein surfaces, which also help hold the proteins together and work against unfolding. It is the folding of the protein that most affects its heat stability and noncovalent, ionic bonds called salt bridges on a proteins surface likely play a major role in maintaining the biologically active structure. Chaperonins: assisting proteins to remain in their native state- chaperonins function to refold partially denatured proteins. Hyperthermophilic Archaea produce special classes of chaperonins that function only at the highest growth temperatures. In cells of Pyrodictium abyssi, a major chaperonin is the protein complex called thermosome. This complex is thought to keep the cells other proteins properly folded and functional at high temperature and help cells survive. DNA Stability at high temperatures: solutes and reverse gyrase- One mechanism increases cellular solute levels, as ions, particularly potassium, and compatible organic solutes affect DNA stability. The cytoplasm of the hyperthermophilic methanogen Methanopyrus contains molar levels of potassium cyclic 2,3-diphosphoglycerate. This solute prevents chemical damage to DNA, such as depurination of depyrimidization from high temperatures. These chemical changes can lead to mutation. Potassium di-myo-mositrol phosphate that protect against osmotic stress. A unique protein found only in hyperthermophiles is the reverse DNA gyrase. Reverse gyrase introduces positive supercoils into DNA. Positive supercoiling stabilizes DNA to heat and thereby prevents the DNA helix from denaturing. DNA stability: DNA binding proteins- a small heat stable DNA-binding protein present in cells of Sulfolobus binds to the minor groove of DNA in a nonspecific manner and increases its melting temperature by some 40 degrees C. This protein called Sac7d, sharply kinks the DNA and thus may also be involved in gene regulation. Lipid stability: Virtually all hyperthermophilic Archaea synthesize lipids of the dibiphytanyl tetraether type. dibiphytanyl tetraether lipids are naturally head resistant because the covalent bond between phytanyl units forms a lipid monolayer membrane structure instead of the normal lipid bilayer. This structure, supported by covalent bonds, resists the tendency of heat to pull apart a lipid bilayer constructed of fatty acids.


--------------------
Points:


I scare little kids.
user posted image

QUOTE (treacherous @ Aug 16 2008, 12:12 PM)
RRRAOAAOAOAORRARRAA!!...  Blue lights and sirens rang through the night!! Yeah, they all wanna kill each other... HERE ME CITY!! THE STREETS BELONG TO THE GANGS NOW!! THIS IS THE NEW ORDER!! PREPARE FOR CHAOS!!

Solomon and I may be gangsta, but treach is the gangsta of the year!
Top
Pseudonym
Posted: Mar 12 2009, 12:56 AM


FPL Failure


Group: Members
Posts: 1,219
Member No.: 203
Joined: 26-January 09



Impressive. How were your hands after writing that?


--------------------
Points: More than Bison


Give me half.
Top
granobulax
Posted: Mar 12 2009, 01:00 AM


He's even got his hand over where I live...


Group: Admin
Posts: 7,880
Member No.: 35
Joined: 31-May 08



QUOTE (Pseudonym @ Mar 12 2009, 12:56 AM)
Impressive. How were your hands after writing that?

They were fine. It took me the better part of three days to look up the information and type it out. Whew, I'm glad that's over.


--------------------
Points:


I scare little kids.
user posted image

QUOTE (treacherous @ Aug 16 2008, 12:12 PM)
RRRAOAAOAOAORRARRAA!!...  Blue lights and sirens rang through the night!! Yeah, they all wanna kill each other... HERE ME CITY!! THE STREETS BELONG TO THE GANGS NOW!! THIS IS THE NEW ORDER!! PREPARE FOR CHAOS!!

Solomon and I may be gangsta, but treach is the gangsta of the year!
Top
Leo Sanders
Posted: Mar 12 2009, 01:58 AM


Monkey King of Haven


Group: Members
Posts: 3,116
Member No.: 42
Joined: 16-June 08



huh.gif ohmy.gif I would be like screw that Im going home...


--------------------
Never give up! 08-05-92

user posted image

Points:
Top
granobulax
Posted: Mar 12 2009, 02:20 AM


He's even got his hand over where I live...


Group: Admin
Posts: 7,880
Member No.: 35
Joined: 31-May 08



laugh.gif

It's what ya got to do when you go to college.


--------------------
Points:


I scare little kids.
user posted image

QUOTE (treacherous @ Aug 16 2008, 12:12 PM)
RRRAOAAOAOAORRARRAA!!...  Blue lights and sirens rang through the night!! Yeah, they all wanna kill each other... HERE ME CITY!! THE STREETS BELONG TO THE GANGS NOW!! THIS IS THE NEW ORDER!! PREPARE FOR CHAOS!!

Solomon and I may be gangsta, but treach is the gangsta of the year!
Top
treacherous
Posted: Mar 12 2009, 03:34 PM


Let Hammy have his Bison. I've got Zod.


Group: Admin
Posts: 3,499
Member No.: 37
Joined: 10-June 08



QUOTE (granobulax @ Mar 12 2009, 02:20 AM)
laugh.gif

It's what ya got to do when you go to college.

That's nothing like what I did in college. Nothing at all. happy.gif


--------------------
Points:

Ursa: You are master of all you survey.
General Zod: [bored] So I was yesterday. And the day before.




QUOTE (SilverSurfer092 @ Apr 9 2009, 03:27 AM)
WTFYES  Treacherous is full of pwnage.
Top
granobulax
Posted: Mar 12 2009, 04:18 PM


He's even got his hand over where I live...


Group: Admin
Posts: 7,880
Member No.: 35
Joined: 31-May 08



QUOTE (treacherous @ Mar 12 2009, 03:34 PM)
QUOTE (granobulax @ Mar 12 2009, 02:20 AM)
laugh.gif

It's what ya got to do when you go to college.

That's nothing like what I did in college. Nothing at all. happy.gif

What did you do in college?


--------------------
Points:


I scare little kids.
user posted image

QUOTE (treacherous @ Aug 16 2008, 12:12 PM)
RRRAOAAOAOAORRARRAA!!...  Blue lights and sirens rang through the night!! Yeah, they all wanna kill each other... HERE ME CITY!! THE STREETS BELONG TO THE GANGS NOW!! THIS IS THE NEW ORDER!! PREPARE FOR CHAOS!!

Solomon and I may be gangsta, but treach is the gangsta of the year!
Top
Solomon
Posted: Mar 12 2009, 07:11 PM


Head Admin


Group: Admin
Posts: 7,680
Member No.: 3
Joined: 9-January 08



I'll give you a hint:

Woman.


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Points:

"The first shot rang out from somewhere and I heard a bullet wiz by my face. With my pump action shotgun ready, I shoot the first fool I see."

Grano's so gangster.
Top
treacherous
Posted: Mar 12 2009, 08:10 PM


Let Hammy have his Bison. I've got Zod.


Group: Admin
Posts: 3,499
Member No.: 37
Joined: 10-June 08



QUOTE (Solomon @ Mar 12 2009, 07:11 PM)
I'll give you a hint:

Women.

fix'd.


--------------------
Points:

Ursa: You are master of all you survey.
General Zod: [bored] So I was yesterday. And the day before.




QUOTE (SilverSurfer092 @ Apr 9 2009, 03:27 AM)
WTFYES  Treacherous is full of pwnage.
Top
Solomon
Posted: Mar 12 2009, 08:59 PM


Head Admin


Group: Admin
Posts: 7,680
Member No.: 3
Joined: 9-January 08



QUOTE (treacherous @ Mar 12 2009, 08:10 PM)
QUOTE (Solomon @ Mar 12 2009, 07:11 PM)
I'll give you a hint:

Women.

fix'd.

happy.gif


--------------------

Points:

"The first shot rang out from somewhere and I heard a bullet wiz by my face. With my pump action shotgun ready, I shoot the first fool I see."

Grano's so gangster.
Top
granobulax
Posted: Mar 12 2009, 09:00 PM


He's even got his hand over where I live...


Group: Admin
Posts: 7,880
Member No.: 35
Joined: 31-May 08



I hear ya. I've been in college three years now and with my wife for two years if ya catch my drift.


--------------------
Points:


I scare little kids.
user posted image

QUOTE (treacherous @ Aug 16 2008, 12:12 PM)
RRRAOAAOAOAORRARRAA!!...  Blue lights and sirens rang through the night!! Yeah, they all wanna kill each other... HERE ME CITY!! THE STREETS BELONG TO THE GANGS NOW!! THIS IS THE NEW ORDER!! PREPARE FOR CHAOS!!

Solomon and I may be gangsta, but treach is the gangsta of the year!
Top
Jailer411
Posted: Mar 12 2009, 09:02 PM


The one and only.


Group: Members
Posts: 2,320
Member No.: 175
Joined: 17-January 09



QUOTE (granobulax @ Mar 12 2009, 03:00 PM)
I hear ya. I've been in college three years now and with my wife for two years if ya catch my drift.

huh.gif ........................... laugh.gif


--------------------
4/24/11 8:48CMT

Signature has been changed, forum remains locked.
Top
granobulax
Posted: Mar 12 2009, 09:45 PM


He's even got his hand over where I live...


Group: Admin
Posts: 7,880
Member No.: 35
Joined: 31-May 08



So, I go to lab tomorrow to check off on phlebotomy, IV insertion, hep lock, solution change, IV dressing change, and central line catheter care.

Wish me luck! biggrin.gif


--------------------
Points:


I scare little kids.
user posted image

QUOTE (treacherous @ Aug 16 2008, 12:12 PM)
RRRAOAAOAOAORRARRAA!!...  Blue lights and sirens rang through the night!! Yeah, they all wanna kill each other... HERE ME CITY!! THE STREETS BELONG TO THE GANGS NOW!! THIS IS THE NEW ORDER!! PREPARE FOR CHAOS!!

Solomon and I may be gangsta, but treach is the gangsta of the year!
Top
treacherous
Posted: Mar 12 2009, 09:45 PM


Let Hammy have his Bison. I've got Zod.


Group: Admin
Posts: 3,499
Member No.: 37
Joined: 10-June 08



QUOTE (Jailer411 @ Mar 12 2009, 09:02 PM)
QUOTE (granobulax @ Mar 12 2009, 03:00 PM)
I hear ya. I've been in college three years now and with my wife for two years if ya catch my drift.

huh.gif ........................... laugh.gif

Took him a minute.


--------------------
Points:

Ursa: You are master of all you survey.
General Zod: [bored] So I was yesterday. And the day before.




QUOTE (SilverSurfer092 @ Apr 9 2009, 03:27 AM)
WTFYES  Treacherous is full of pwnage.
Top
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