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105 Cards in this Set
- Front
- Back
-virus of bacteria
-prevalent in soils, freshwater, and oceans -Active in biologic turnover and genetic transfer -1/3 bacteria mortality -70% marine prokaryotes infected |
Bacteriophage
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Classification of bacteriophages based on two criteria
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phage morphology, nucleic acid properties
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What type of bacteriophage lyses their host following infection (T4)
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lytic phage
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What type of bacteriophage incorporates their genome into the host bacterium's genome and replicates along with the host until a lytic phase is induced? (lambda)
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Lysogenic, Temperate phage
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What is the bacteriophage cycle that results in the host cell bursting and releasing virions?
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lytic phase
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What are proteins of a bacteriophage that take over RNA polymerase for virus's mRNA?
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sigma factor
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What enzyme makes bacterial DNA available for manipulation?
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Nuclease
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What enzyme causes cell membrane penetration/lysing?
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lysozyme
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Which bacteriophage contains 5-hydroxymethl-cytosine (HMC) instead of cytosine?
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T4
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What happens to HMC of the T4 phage in order to protect if from restrition endocucleases?
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It is glucosylated.
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What enzymes are used by bacteria to protect themselves by cutting up foreign DNA?
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restriction endonucleases
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What is a long strand of viral DNA consisting of several units linked together that is cut up haphazardly and inserted in new viral heads?
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concatamer
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What is induced or triggered by a drop in levels of lambda repressors(can be caused by exposure to UV light or chemicals that cause DNA damage)
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lytic cycle
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What enzyme binds integrase and acts to reverse the integration process of viral DNA in order to induce reproduction?
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excisionase
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What can induce changes in host phenotype, for example the modification of Salmonella lipopolysaccharide structre or the production of diphtheria toxin by Corynebacterium diphtheriae?
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lysogeny
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Which bacteriophagal protein attacks the peptidoglycan of the bacteria?
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endolysin
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Which bacteriophagal protein produces lesions in cell membranes?
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holin
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What is the nonlytic relationship between a phage and its host that usually involves integration of phage genome into host DNA?
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lysogeny
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What is the phage genome which will be integrated into the host genome?
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prophage
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what enzyme causes the phage genome to integrate with the host genome?
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integrase
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What enzyme glues the DNA into a circular shape and glues it into the host?
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ligase
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What infections are incurable, usually detectable, and have mild or absent clinical symptoms? (ex. Hepatitis B, HIV)
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chronic virus infections
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What infections have viruses that stop reproducing and are dormant for some time, during which they are not detectable? (ex. HSV, varicella-zoster)
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latent infections
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What enzyme of retroviruses takes single RNA to single DNA to double DNA to mRNA?
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reverse transcriptase
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Which disease is a retrovirus that infects T helper cells and is released by budding?
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Human Immunodeficiency Virus
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What is fresh food generally of high Aw that has a very short shelf life? (vegetables, meats, eggs)
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perishable food
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What is food of intermediate Aw that has a limited shelf life (potatoes, nuts)
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semiperishable food
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What is food of low Aw that has an extended shelf life (sugar, flour, rice)
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nonperishable food
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What are the cold, pickling, acidity, dehyrdation, heating, chemical, and irradiation used for?
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food preservation
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What is the danger temperature zone for bacterial growth?
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4C-60C
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What is the Aw and NaCl amounts at which most bacteria will not grow
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.957, 7.5%
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what causes the pH of dairy products, meat products, and bread and vegetable products to be lowered through fermentation?
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lactic acid
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What is a disease resulting from ingestion of foods containing preformed microbial toxins?
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Food poisoning
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What is an infection resulting from the ingestion of a pathogen?
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Food infection
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Which gram type of bacteria usually cause food poisoning
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Gram +
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Which gram type of bacteria usually cause food infections?
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Gram -
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What is the process of isolating a causal organism, inoculating samples into an enriched media, transfering to selective media for isolation and identification?
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Microbial sampling
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What two things are looked for in indentification of bacteria?
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growth characteristics, genetic fingerprinting
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B: Food poisoning
-thrives in high-salt and low Aw habitats -Sources: skin, respiratory tract -Most common enterotoxin producer -Enterotoxin is extremely resistant to heat and digestive proteases |
Staphylococcus aureus
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B:Food poisoning
-185,000 cases per year -Foods: creamy goods, p/m, egg/meat salads (foods kept at room temp) -Symptoms: nausea, vomiting, abdominal pain, diarrhea, weakness, subnormal body temp -Onset: 1-7/2-4 hours -Duration: 1-2 days |
Staphylococcus aureus
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B: Food poisoning
-Sources: soil, sewage (GI) -most prevalent cause of food poisoning -Produces many toxins: protein exotoxin, type A, enterotoxin |
Clostridium perfringens
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B: Food poisoning
-248,000 cases per year -Foods: m/p/f, dehydrated soups, sauces, bulk foods (left at 20-40C for short time periods) -Spores activated by cooking and germinate under anoxic conditions -Sporulation triggers production of enterotoxin Symptoms: cramps, diarrhea, nausea, fever Onset: 7-15 hours Duration: 12-24 hours |
Clostridium perfringens
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B: Food poisoning
-Sources: soil water -produces neurotoxin that causes paralysis toxin produced best in high protein, low acid foods that have been heated to inactivate competitors and activate spores -Toxins are destroyed by high heat |
Clostridium botulinum
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B: Food poisoning
-155 cases per year -Foods not cooked after processing (nonacid home-canned vegtables, smoked and fresh fish) -home-canned foods>72% -infant botulism occurs in infants up to 2 months (70% cases) -Symptoms: double/blurred vision, cramps, vomiting, nausea, constipation, heart paralysis, difficulty in swallowing, speaking and breathing -Onset:12-36/6-18 hours -Duration: 1-10 days to life -mortality: 21% |
Clostridium botulinum
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B: Food infection
-sources: sewage (GI) -S. thyphimurium is the most common agent of salmonellosis gastroenteritis |
Salmonella
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B: Food infection
-40,000-45,000 cases per year (may actually be 1.3 million) -Foods: p/m, vegetables, eggs, creamy things, dairy products -Infectious dose-10^7-10^9 -endotoxins cause symptoms -most strains are pathogenic -Symptoms: diarrhea, abdominal cramps, fever, nausea, vomiting, chills -onset: 5-72/12-36 hours -duration: 2-3 days to life, 10-20% victims become carriers for 4-8 weeks |
Salmonella
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B: Food infection
-source: sewage (GI) -infectious dose: 10^6-10^10 -Categories: enterophatogenic (infantile d), enteroinvasive (shigela-like d), enterotoxigenic (traveler's d), and enterohemorrhagic (bloody d) - most strains are not pathogenic |
Escherichia coli
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B: food infection
-73,000 cases/61 deaths per year -leading cause of kidney failure in children -Foods: meat and diary products (most common is undercooked meat) -verotoxin attacks kidneys & intestines -killed by radiation -Symptoms: bloody stools, abdominal pain, kidney failure, brain damage, death -Onset: 2-8/3-4 days -duration: 5-10 days Infection dose: as little as 10? |
E. Coli O157:H7
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B: food infection
-sources: GI of animals -most prevalent cause of bacterial foodborne infections -heat tolerant -destroyed by pasteurization, freezing, air, and gastric acid |
Campylobacter jejuni
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B: Food infection
-2 million cases per year -Foods: m/p, raw clams, dairy -invades epithelium of intestine -produces enterotoxin and cytotoxin -infectious dose-500-10^6 -symptoms: diarrhea, cramps, high fever, ulceration of ileum, malaise -onset: 2-5 days -duration: 1-4/10 days |
campylobacter jejuni
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B: food infection
-acid-tolerant, psychrotolerant, salt-tolerant -Sources: soil, water, fecal material, vegetation -invades and lives in phagocytes -produces several toxins |
Listeria monocytogenes
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B: food infection
-2500 cases per year/500 deaths -Foods: raw milk, soft cheese, cabbage -infectious dose - 1000 -Symptoms: fever, muscle aches, nausea, diarrhea, meningitis, confusion, loss of balance, abortion -onset: days to 3 weeks -duration: few days to life |
Listeria monocytogenes
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-Cause of most foodborne infections
-Symptoms: diarrhea, nausea, vomiting -Duration: 24-48 hours |
virus
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virus responsible for most mild foodborne infection in the US (9-13 million)
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Norwalk-like virus
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rotavirus, astrovirus, and hepatitis collectively cause 100,000 what ________
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cases of foodborne illnesses
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Protozoa spread via food contaimined by fecal matter in untreated water that is contracted for life
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Giardia lamblia
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Protozoa spread via food contaminated by fecal matter in untreated water that is resistant to chlorine
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Cryptosporidium parvum
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Protozoa spread via food conatiminated by fecal matter in untreated water
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Cyclospora cayetanensis
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Protozoa spread through cat feces or under cooked meat that can cause blindness and stillbirth with prenatal infection
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toxoplasma gondii
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Infectious agent made of proteins that causes disurption in neural tissue with symptoms of depression, loss of motor coordination, dementia, and death
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prion
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prion linked to consumpion of meat products from cattle afflicted with BSE
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nvCJD
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Relationship where both populations benefit
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mutualism
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condition of metabolic benefits for symbiotic populations
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syntrophy
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relationship where one population benefits and the other is not affected
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commensalism
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relationship were there is no impact on either population by cohabitation
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neutralism
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relationship where one population is negatively affected by the presence of other
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parasitism
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air, water, soil, rocks
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abiotic components
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members of a microbial species or closely related organisms
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populations
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members of metabolically related microbes
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guilds
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microbes within a habitat interacting with each other
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community
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abiotic components of the habitat and the microbial community
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ecosystem
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for every organism, there exists at least one
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prime niche
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specific place where a microorganism actually lives
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microenvironment
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bacterial assemblages attached to a surface and enclosed in adhesive polysaccharides excreted by the cells in order to provide higher concentrations of nutrients and protection
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biofilm
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Bacterial genes expressed only when attached to surfaces in order to make polysaccharide adhesives and protein communicators
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biofilm-specific genes
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cell-to-cell communication
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quorum sensing
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potential biofilm preventative
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furanones
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soil around roots with most extensive microbial growth
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rhizosphere
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Which water environment has stratification in oxygen amounts
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Lakes
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which water environment is impacted by carbon levels and tested with BOD
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Rivers
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Which water environment has lower nutrients, bacteria in surface water, and archaea in deeper waters
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open ocean
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which water environment is cold, dark, and high hydrostatic pressure and also chemolithotrophic bacteria that live near hydrothermal vents?
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deep ocean
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Where does the majority of CO2 come from ?
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decomposing organic matter
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What organisms are the foundation of the carbon cycle?
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photosynthetic organisms
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which types of bacteria form CO2?
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chemolithotrophs?
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What is the principal form of nitrogen on earth?
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N2
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How is ammonia formed?
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nitrogin fixation of nitrogen gas
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How is nitrite converted to nitrate?
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nitrification
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how is nitrate converted to nitrogen gas?
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denitrification
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What is the order of the nitrogen cycle starting from nitrogen gas?
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N2-ammonia-nitrite-nitrate
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product of metabolism that is produced during active cell growth (exp. phase)
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primary metabolite
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product of metabolism that is produced near the end of the exp. phase or in the stationary phase and is not essential for growth and may be overproduced (used for industrial production
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secondary metabolite
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pilot-scale of industrial fermentations
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300-3000 L
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commericial scale of industrial fermentations
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>3000 L
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antibiotics, vitamins, amino acids, and enzymes are all examples of________
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industrial products
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grape juice containing carbohydrates in readily fermentable form
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must
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hydrolysis of complex carbohydrates in cereals by addition of water and heating mixture
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mashing
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clear liquid containing fermentable carbohydrates
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wort
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alcohol added to alcoholic beverage
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fortified
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most sugars of alcoholic beverage used in fermentation
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dry
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germinated barley grains having activated enzymes
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malt
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malt after being mixed with water in order to hydrolyze starch to usable carbhydrates
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mash
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yeasts used in production of beers
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bottom yeasts
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yeasts used in production of ales
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top yeasts
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flower added to wort for flavor and antimicrobial purposes
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hops
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