Which of the following terms represent a collection of diverse microbes and their interactions with the abiotic factors which surround them?
Which of the following roles are BEST associated with cyanobacteria?
c. primary producer
c. primary producer
What percentage of all the cells associated with the human body are actually human eukaryotic cells (by number, not mass)?
Which of the following represents a cultivation-dependent manner to explore microbial diversity?
a. fluorescent in situ hybridization
b. winogradsky column preparation
c. metagenomic library screening
d. flow cytometry sorting
b. Winogradsky column preparation
In what ecosystme are you MOST LIKELY to find a piezophile?
a. hydrothermal vent
b. o horizon of soil
c. tundra biome
d. desert biome
a. hydrothermal vent
Which of these would be an example of a "primary metabolite" fermentation product?
b. starvation proteins
If you want to harvest secondary metabolites produced by microbes, which stage must the culture be in of its growth cycle?
b. log (exponential)
Which of the following factors are not able to be controlled in an industrial bioreactor to ensure optimal growth conditions?
a. nutrient levels
c. oxygen levels
d. all are controllable
d. all are controllable
The mass production of bacterial lipases would most likely fall under the category of...
a. red biotechnology
b. white biotechnology
c. blue biotechnology
d. green biotechnology
b. white biotechnology
Engineering bacterial cells to produce human growth hormones would fall under...
a. red biotechnology
b. white biotechnology
c. green biotechnology
d. none of these headings
a. red biotechnology
Distinguish between a primary metabolite and a secondary metabolite.
the metabolic products of growth by an organism are termed primary metabolites. They are produced when the organism is actively growing. Secondary metabolites are those produced by processes not required for the growth of the organism, such as antibiotics. They are typically produed in the stationary phase of teh organism's growth curve.
How does the pharmaceutical industry use microbes to produce drugs that are effective at guarding against some of these disease-causing microbes?
Microorganisms produce anti-microbial compounds as secondary metabolites to restrict the growth of other microorganisms in their natural habitats. The pharmaceutical industry harnesses these secondary metabolites and develops methods to produce large quantities of these compounds cheaply, for use in guarding against disease-causing microbes in humans.
What is a biorefinery? How can it be used?
A biorefinery is a system that uses living or recently dead biological material as raw materials to generate chemicals, energy and materials such as bioplastics.
In order for a eukaryotic gene to be expressed in bacteria, it is necessary for the expression vector to include...
Although biofuels are promising sources of alternative energy, there are still barriers to widespread adoption including...
the energy required to grow and process foodstocks may be greater than the energy in the biofuels
Some microbes produce natural polymers that can be used as alternatives to plastics. Why would a microbe produce such a molecule?
these molecules form as carbon and energy storage products
How does the Bt toxin work?
Bt proteins are ingested by insects where they are processed and ultimately damage the insect gut.
The practice of biopropecting looks to _ for microbes with _ properties.
Red biotechnology (as opposed to white or green biotechnology) refers to...
medical and pharmaceutical biotechnology
Why does Roundup (glyphosate) have to be applied before planting crops to be an effective herbicide?
it targets a pathway common to both weeds and crop plants
What is a biofilm? Where can biofilms be found?
a biofilm is an accumulation of microorganisms on solid surfaces to form stable, structure communities of microbes supported by an extracellular polysaccharide matrix. Biofilms form on surfaces that are capable of picking up nutrients and exposed microbes, such as rocks in streams, plague on teeth and in shower drains.
What is oligotrophy?
metabolism using nutrients at very low concentrations, which typically occurs in ocean ecosystems since nutrients are present in minor amounts.
Which of the following statements regarding A, B, and C soil horizons are false?
The deepest layer, the C horizon, is close to the bedrock and is composed mostly of organic matter
The primary energy generating pathway in the mid water zone of oceans likely...
The theory behind cometabolism, a strategy for remediating contaminated soils, is...
adding natural substrates will induce other degradation pathways
Terrestrial hot springs differ from hydrothermal vents in that...
hot springs are driven by photosynthesis rather than chemolithotrophy.
The difference between the biological species concept as applied to plants and animals and teh operational taxonomic unit concept applied to bacteria is...
the biological species concept is based on reproductive isolation while the operational taxonomic unit is based on SSU rRNA sequence similarity
The rhizosphere (soils associated with roots) contains more microbes than bulk soil (soil not associated with roots) becuase of availability of...
Fungi are noteworthy as decomposers because they are the only group of microorganisms capable of breaking down..
The dominant form of primary productivity in terrestrial, depp subsurface habitats is...
How do foodborne and waterborne pathogens cause diarrhea?
enterotoxin action stimulates water and electrolyte release from teh cells lining the gut, resulting in diarrhea and dehydration
Differentiate between foodborne infection and foodborne intoxication.
a foodborne intoxication refers to illness caused by ingestion of microbial exotoxins (i.e. S. aureus)
The principle behind irradiation as a mechanism to prevent food spoilage is...
the nucleic acid of living cells is damaged, resulting in the death of any potential food spoilage microbes
the biological oxygen demand during the secondary treatment of wastewater is expected to be...
high becuase large numbers of bacteria actively metabolize water with high organic content
The presence of fecal coliforms in a water sample indicates...
the water has likely been contaminated by human fecal matter from raw sewage
Modified atmosphere package (MAP) helps to preserve food by...
removing oxygen from the atmosphere
Typically, agents of foodborne illnesses target the...
In the world of wastewater treatment, floc is defined as...
clumps of bioass consisting of absorbed material and biofilm microorganisms
The primary difference between perishable and non-perishable foods is the availability of...
The principle behind canning as an effective means of food preservation is...
exposure to high temperature under pressure for an extended period of time reduces the number of potential spoilage organism
What are the major differeneces between type I diabetes and type II diabetes?
type I: insulin dependent, in which the beta cells of the pancreas are destroyed, so little or no insulin is produced
type II: insulin resistant, in which insulin is produced by the pancreas but cells of the body do not respond to insulin in the blood
What is the physiological role of insulin in the human body?
insulin is a protein (hormone) that is secreted by the pancreas that acts to lower blood glucose levels. When blood glucose levels are high, insulin is released into the blood and binds to insulin receptors on cell surfaces, wihch triggers the translocation of the GLUT4 transporter protein to the cell membrane. Glucose is then able to enter the cell through the GLUT4 transporter, thereby lowering blood glucose levels.
Why does the author refer to insulin as "cow juice" originally?
insulin was originally isolated from teh secretions of bovine pancreas and then purified as a treatment for type I diabetes.
Why was the direct injection of animal (bovine) insulin problematic for some patients?
common adverse side effects included: formations of abscesses, pain and swelling at the injection site. Some patients had fatal allergic reactions. The purification process led to irregularities in insulin concentration which resulted in under-dose and over-dose situations.
How was semi-synthetic insulin different than the bovine-derived insulin?
the semi-synthetic form was chemically derived from porcine insulin. Porcine differs from human insulin at one amino acid while bovine insulin differs at three amino acids. The porcine insulin was easily modified after purification by chemical treatment to the same sequence of amino acids as found in human insulin.
What were the advantages of using semi-synthetic human insulin over bovine-derived insulin?
less chance of a fatal allergic reaction
When did recombinant human insulin become available for sale and who was the manufacturer?
1982: Eli Lilly and Company marketed the product under the name Humulin
What organism(s) is/are used to produce recombinant human insulin?
E. coli was the original host for the recombinant plasmid, but more recently Saccharomyces ervisiae (yeast) has been used as a host.
What would be the advantage of using Chinese Hampster Ovary (CHO) cells as a host for recombinant human proteins over E. coli?
less genetic manipulation to the genome and expressed proteins would be required since the host cell is also eukaryotic- e.g., no need to remove introns from genome.
What are the potential sources of introduction of fecal coliforms into the Oconee River (limit yourself to teh context of the scenario)?
Animal: wild fauna feces, chicken feces from chicken farm, cow manure (= soybean field fertilizer), humnas (swimmers/canoers)
Industrial: effluent released into river by poultry processing plant
Why do we use fecal coliforms as an inidcator species and not just try to isolate a pathogen of interest?
There are too many specific pathogens for which we'd have to test and that costs time and money. Pathogens are often weak and may not be culturable until they've regained strength (this could happen in a human host and disease would develop afterwards).
Do fecal coliforms normally cause disease? If yes, hwat diseases can be associated with them?
E. coli, our model fecal coliform and indicator species, is not normally a pathogen of the gastrointestinal tract. In fact, it is widely considered a commensal microbe of the intestines and beneits its human hosts greatly with the production of vitamin K. However, pathogenic strains of E. coli do exist adn cause mild gastroenteritis to devilitating diseases such as hemolytic uremic syndrome.
In the scenario, which site(s) exceed the EPA's limits for fecal coliform safety? (Note the sampling week as well.)
week 1: NC1 and NC3
week 2: DBC1, BC1, NC1 and NC3
week 3: DBC1, BC1, BC2, NC1, NC2, NC3 (all sites)
week 4: BC1, BC2, NC1, and NC3
Site NC1 (which is the furthest site downstream in the study) shows consistently high levels of fecal coliforms. Determine if you should support the resident's efforts to accuse the poultry processing plant (DBC1) or is there another likely source.
I would not side with the local residents against the poultry processing pland and instead suggest that the chicken farm is teh point source of the major intro of fecal coliforms on the river.
What influenced the sudden increase in fecal coliforms in all sampling sites during week 3?
siginificant precipitation that would result in runoff from the terrestrial soil. the weather was also warm and could enhance coliform growth
What could explain the unusually high data for sites BC1 and BC2 in week 4?
-native fauna fecal droppings near sampling location
-coliform introduciton from towns/cities north of affected sampling point
-farms used manure fertilizer
-stagnation due to no rain could cause "pools' for coliform incubators
If starter cultures are not added to pasteurized milk, can one successfully make cheese still? Explain why or why not.
Yes! The natural lactic acid bacteria found in milk and which survived the pasteurization process would grow in number and perform the same function as the starter culture. Before we began using starter cultures, this is how microbially fermented foods were produced.
What is the general metabolic product which is produced by bacteria that changes milk to curds and whey?
lactic acid bacteria ferment a variety of sugars, particularly lactose, to lactic acid. the strong acidic condiitons that result from their metabolic activity cause proteins (case in) in milk to be denatured. Specifically, the case in proteins begin to thicken and form soft curds in the acidic environment.
Why do cheesemakers often add rennet to milk in addition to bacterial starter culutres?
Rennet is an enzyme that causes the milk caseins to form a solid curd and complements the action of lactic acids. The curd is tighter and contains less water when rennet is used than when acid alone is used- this is preferred for some varieties of hard cheeses especially.
The authors say that different cheeses are heated to different temperatures to form the curd. Why might this be important?
some cheesemaking bacterial cultures are mesophiles adn asome are thermophiles. heating the milk to the optimal growth temperature of the culutre used will speed up cheese curd formation ripening
Are all cheese ripened? What does that mean, anyway?
Ripening refers to the maturaiton of cheese by microbial agents (bacteria and molds) which develop the flavor, texture, body and aroma associated with a cheese variety. Not all cheese are ripened and are considered fresh cheeses instead of ripened cheese (cottage and cream cheese)
Which types of cheese undergo a hot water treatment after the curds are formed? Why is this neccessary?
Mozzarella, provolone and string cheese curds are all subjected to a hot water treatment after the curd is formed.
The heating and cooling cycles along with kneading of the curd produce a stretchy texture in the finished cheese.
What does it mean to "cheddar" a cheese?
Cheddaring refers to process of forming curds into large slabs which are subjected to heat after the curd is formed to prompt additional removal of whey and the turning of curds roughly every 30 minutes during this treatment. Finally, the drier cheddar curds are cut into smaller chips or strips before they are pressed into a tight curd once again.
Compare and contrast the work force needed to produce the same mass of cheese as a small farm dairy with an industrial plant.
Industrial plants are highly mechanized in their processing which requires little manipulation by humans and a crew 2 or 3 individuals can quickly produce huge masses of finished cheese in a single day, whereas in small dairy farms, in order to produce the same mass, it would take several large crews several days of the week (if not longer) to reach an equivalent production
IN cheddar cheese production, to what do the terms "sharp" and "extra sharp" refer?
sharp and extra sharp refer to how long the cheese is aged and generally refers to the tanginess of the taste produced as a result of continued microbial metabolism of fats and proteins in the milk once the sugars have been exhausted. Sharp cheese is typically aged 6 to 9 months aged while extra sharp typically undergoes 1 to 1.5 years of aging.
Why do you suppose cheesemakers recommend that you don't use ultra-high pasteurized milks as a starting material for cheese?
In UHT milk, the protein have most likely been damaged (denatured) due to the high temperature exposure and the addition of acid and rennet will no longer have the same effect. many cheesemakers suggest that UHT milk can still be used to make ricotta, and indicate the curds will be smaller and may be tighter/drier than if HTST milk was used.
Which of the following spoilage-prevention techniques can be specifically directed the DNA of all microbes?
Which of the following represents a perishable food?
Which of the following products depend on fermentation by fungi (molds)?
Which of the following is likely the MOST likely outcome if one were to ingest undercooked seafood contaminated with bacteria which invade human intestinal cells?
food born infection only
During which stage of wastewater (sewage) treatment are bacteria used to reduce nutrient concentrations?
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