Test Questions on Final Exam – Flashcards

Unlock all answers in this set

Unlock answers
question
How many different serotypes or species of salmonella are there?
answer
30
question
Food spoilage can come from many microbial sources. What are some of them?
answer

Moldy bread - fungi

Contaminated meat - bacteria

Shellfish - live in brackish water which has many toxins

 

question
What was the strain of salmonella that is associated with a breakout in a correctional facility that was traced back to Tyson's chicken? Why was this strain such a problem?
answer

Heidelburg; pan resistant 75%

 

question
How long does it take the CDC/FDA to gain enough info to identify a strain associated with an outbreak/make a recall on food?
answer
1-2 weeks
question
How does the CDC/FDA identify the species of salmonella? What area of micro is associated with this?
answer
Identifications made by analysis of DNA. Molecular biology
question
Who is most at risk for death from food poisoning?
answer
Young children and the elderly. Not a large killer of healthy individuals.
question
Factors influencing microbial growth
answer

Water content

pH

Physical structure

Chemical composition

O2 availability

Temperature

question

Describe the requirement for microbial growth:

 

Water content

answer
Microbes need water. Very dry foods have less microbes
question

Describe the requirement for microbial growth:

 
pH
answer
Neutral is more preferable
question

Describe the requirement for microbial growth:

 
Physical structure
answer

Ground beef has more microbes than steak.

If a fruit or vegetable has a peel, it protects it better against microbes

How food is stored is also important

question

Describe the requirement for microbial growth:

 
Chemical composition
answer
Foods that are more acidic will have less microbial growth.
question

Describe the requirement for microbial growth:

 
O2 availability
answer
Microbes need lots of O2
question

Describe the requirement for microbial growth:

 
Temperature
answer
Mesophilic
question
What do molds breakdown?
answer
Carbohydrates
question
Molds like a high ______ content
answer
sugar
question

The following foods are perishable/nonperishable:

 

fish, poultry, eggs

answer
Perishable; spoil quickly
question

The following foods are perishable/nonperishable:

 
dry spaghetti, dry beans, coffee, raisins
answer
nonperishable; last a long time without going bad
question
The consumption of _____ or ______ can cause food poisoning and infections
answer
toxins or microorganisms
question

Intrinsic or extrinsic?

 

Antimicrobial substances, some herbs tend to carry foodborne bacteria, polyphenol

answer
Intrinsic
question
Intrinsic or extrinsic?
answer
temperature, humidity, contaminating organisms
question
A toxin produced by aspergillus flavus that is cancer causing in vertebrates; linked to liver and colon cancers
answer
Aflatoxin
question
What produces aflatoxins?
answer
Aspergillus flavus
question
What is aflatoxin accumulated in?
answer
Grains, nuts, corn
question
A condition inducing convulsions and hallucinations from fungal toxins in rye
answer
Ergotism
question
What causes ergotism? And what famous historical event is it associated with?
answer
Claviceps purpurea; Salem witch trials
question
Claviceps purpurea which causes ergotism, is found in what?
answer
Rye, wheat, barley
question
What are some physical methods of controlling microbial growth in food?
answer
Filtering, refrigeration, freezing, heat
question
This is used in deli meats. High volume of CO2 (60%) reduces the oxygen content in bacterial, therefore reducing gram negative bacteria on meat.
answer
Modified atmosphere packaging
question
How does heating affect microbes?
answer
Heat kills microbes
question
How does refrigeration affect microbes?
answer
Refrigeration slows the growth of microbes
question

What are the following known as?

 

Propionic acid

Sorbic acids

Benzoic acids

Sulfites

Sodium diacetate

Sodium nitrite

 

answer
Preservatives
question

Identify the preservative:

 

Prevents molds on bakery goods

 

inhibits enzymes by lowering pH

 

Preservative for both animal feed and food for human consumption

answer
Propionic Acid
question
Inhibits enzymes by lowering pH
answer
Identify the MOA of propionic acid
question

Identify the preservative:

 

Natural organic compound

All salts are associated with this preservative

Prevents molds in cheeses, syrups, cakes

Prevents growth of mold/yeast/fungi in food and drinks (pop and juices)

answer
Sorbic acid
question

Identify the preservative:

 
prevents molds in margarine and low pH products
answer
Benzoic acids
question

Identify the preservative:

 
Wines, lemon juices (NO meats)
Dried fruits
inhibits enzyme that causes "browning"
Can potentially make allergies worse
Antibacterial and antifungal SO2
answer
Sulfites
question
What is the enzyme that causes "browning"?
answer
Phenolase
question

 

Inhibit enzyme that causes "browning"

answer

 MOA of sulfites

 
question

Identify the preservative:

 
Prevents molds on breads
answer
Sodium diacetate
question

Identify the preservative:

 
Prevents botulism (clostridum)
Inhibit iron-sulfur clusters
Inhibits lipid oxidation
Found in chicken and hotdogs
Can form nitrosamine-this can be inhibited by vitamin C
Do not consume when pregnant
answer
Sodium nitrite
question
Inhibition of iron sulfur clusters which are essential to energey metabolism of Clostridium botulinum. Inhibits gram neg bacteria
answer
Sodium nitrite
question
What is our concern with the use of sodium nitrite as a preservative?
answer
Nitrosamine formation; this occurs when the preservative is cooked and it combines with amino acids to produce nitrosamine which is a known carcinogen :(
question
What can help prevent nitrosamine formation?
answer
Vitamin C; asorbic acid
question

Identify the preservative:

 
Phenolase inhibitor
Found with vitamin C as an antioxidant
Derivatives prevent fat oxidation
answer
Citric acid and asorbic acid
question
One of a group of bacterial proteins toxic to other bacterial cells. Produced by bacteria to kill bacteria (attach to plasma membrane and lyse cell)
answer
Bacteriocins
question

Identify the preservative:

 
Produced from lactococcus lactis
Contains bacteriocins which are an antibioitic compound that kills bacteria
Found in lloyds pulled pork
answer
Nisin
question
Contains bacteriocins which attach to plasma membrane of bacteria and lyse cell
answer
Nisin
question

Identify the food-borne disease:

 

Bacterial pathogen found in deli meats that causes food poisoning. Found mainly in prepackaged deli meats. Considering use of bacteriophage spray to reduce instances.

answer
Listeria
question

Identify the food-borne disease:

 

Norwalk virus. Named after Norwalk Ohio. Get it from food, direct/indirect contact. Found in shellfish and salad.

answer
Norovirus
question

Identify the food-borne disease:

 

Found in ground beef that is undercooked

answer
E.Coli 0157:H7
question

Identify the food-borne disease:

 

Toxin producer found in eggs

answer
Shigella
question

Identify the food-borne disease:

 

Found in shellfish, causes GI disease

answer
Vibrio parahaemolyticus
question

All the following foods are an example of what?

 

Milk products, meat/fish, alcohol, breads, tofu, tempeh, pickles/kraut, soy sauce, kimchi

answer
Foods fermented by microbes
question
Bacteria involved in making cheese. Also found in buttermilk, sour cream, and keifer
answer
lactobacillus, lactococcus lactis
question
Where does milk pick up bacteria?
answer
Sterile in cow's udder, picks up bacteria in the milking process
question
This is what you innoculate foods with. Isolated bacteria. Many people retain small amounts of previously made yogurt, cheese, etc.
answer
Culture/starter
question
How do lactobacillus and lactococcus lactis work?
answer
They ferment lactic acid from lactose
question
How do cultures/starters affect food?
answer
Lower pH
question
What is the liquid part of cottage cheese/yogurt called?
answer
Whey
question
When milk curdles to form cheese or cottage cheese, what is produced and what is formed?
answer
Acid is produced and caseinase is formed
question
What is the sugar found in milk
answer
lactose
question
What is the #1 species for making cheese?
answer
Lactococcus lactis
question
Mongolian. Kept in leather bag which is easy to keep fermented. Can have some alcoholic content
answer
Kefir
question
What must you first do with milk or sour cream before innoculating it?
answer
Boil to kill bad bacteria
question
Contains more protein and less whey. More compacted. Also contains a different strain of lactococcus
answer
Greek yogurt
question

Contains streptococcus thermophilius and lactobacillus bulgariucs; like around 75-80 degrees celsius.

 

Created through a thermophilic process

 

answer
Yogurt
question
Where do microbes originate in foods like sausage, salami and pepperoni?
answer
Microbes comes from casings and environments in which the food is made
question
_______ foods are more easily preserved, known to have a high number of vitamins, easily digestable, antioxidants, probiotics
answer
Fermented foods
question
Yeast does fermenting. Do not want bacteria involved or present. Produces carbon dioxide gas during process
answer
Production of Ethanol/Alcohol
question
What is important when fermenting alcohol?
answer

No bacterial contamination

No air otherwise the yeast will produce ethanoic acid which is the chemical in vineagar

question
If air is allowed in fermentation of alcohol, what will be produced?
answer
Ethanoic acid - chemical found in vinegar
question
What is the beer starter known as?
answer
wort
question
What is involved in the making of bread?
answer
Fermentation; yeast is mixed with dough and kept warm. Carbon dioxide makes the bread dough rise and alcohol evaporates
question
Set of freeze dried bacteria that will activate when they reach the colon
answer
Probiotics
question

Must not be pathogenic or carrying resistance genes

Must be able to get past acidic environment of the stomach

Very strict regulations

answer
Probiotics
question
These are given preemptively to cattle, chickens to prevent campylobacter and salmonella.
answer
Probiotics
question
What kind of microbes do the work of composting?
answer
Aerobic microbes
question
How long must composte be treated in order to be usable at OU?
answer

14 days inside composting machine

90 days outside 

question
What must be present inside the in vessel composter at OU for composting to happen?
answer
Needs air. Has a lot of fans to keep O2 going so that microbes and other organisms are kept alive
question
What goes into the composter here at OU?
answer

Paper

Food waste

Service ware PLA

Bulking agent (mulch, etc.)

question
Process by which organic substances are broken down into smaller compounds by living microbial organisms
answer
Biodegradation
question
What is the gas produced from landfill waste?
answer
Methane
question
What gives earthy smell to compost?
answer
Actinomycetes
question
What microbes do the work of composting?
answer

Mesophiles: lactobacillus spp acetobacter

As it heats up, thermophiles take over: bacillus spp and actinobacteria

question
What should end product of compost not contain?
answer
Pathogens or viable seeds
question
EPA waste diversion mandates that federal agencies must reduce waste by ____ by fiscal year 2015.
answer

50%

 

States mandate states

question
How many tons of food are produced each day at OU?
answer
6 tons daily
question
A corn/starch based bioplastic that can be broken down in a landfill in 14 days compared to the 1,000 years of other plastics that arent treated
answer
Plastarch material
question
Organic substances are broken down into smaller compounds by living microbial organisms
answer
Biodegredation
question
Bacteria ferments sugar by bacteria and turns it into lactic acid. Lactic acid beads are then formed into products. This is biodegradable. Cannot be heated!
answer
PLA plastic
question
Why do we need biodegradable plastic?
answer
2 large patches in each ocean of garbage approx size of pennsylvania. These flow and vortex in oceans. Contain hundreds of microbes that help break down plastic-many vibrio species
question
Water borne pathogens; fecal contamination
answer
Coliforms
question
Indicator species of fecal contamination; most common?
answer
E.Coli
question
What is the 3 step process of water purification? (drinking water)
answer

Sedimentation

Filtration

Chlorination

question

Identify the process of drinking water treatment:

 

Removes large objects and particles through flocculation

answer
Sedimentation
question

Identify the process of drinking water treatment:

 

Removes microorganisms by passing water through a layer of sand, gravel, microbe biofilm, carbon

answer
Filtration
question

Identify the process of drinking water treatment:

 

Involves addition of chlorine gas to kill remaning organisms

answer
Chlorination
question
What are the two techniques used to determine numbers of bacteria in a water sample?
answer
Membrane filter technique, standard plate count (SPC)
question
Test determines number of bacteria by observing carbon dioxide gas production
answer
Most probably number (MPN)
question
Who regulates water quality?
answer
EPA
question
What is acceptable level of coliforms for drinking water?
answer
Less than 1 coliform per 100 ml's
question
If coliforms are found in more than ___% of drinking water, quality isnt accepted
answer
5%
question
What are the three steps in sewage treatment?
answer
Screen, sediment, sludge. Ends with chlorination
question
What happens once waste water is turned to sludge?
answer
Done aerobically and anaerobically; can be turned into fertilizer or dried and buried
question
What are the 3 biochemical cycles?
answer

Carbon

Nitrogen

Sulfur

question
What do soil microorganisms do?
answer
Break down organic molecules from dead and dying things
question
These organisms convert Co2 into carbohydretes - carbon fixation
answer
Photosynthetic organisms
question
What retains most of the carbon in our atmosphere?
answer
Oceans
question
Convert dead organic matter to release CO2 for reuse by plants
answer
decomposers
question
What must atmospheric carbon be kept at to keep global warming at halt?
answer
350 ppm's
question
What is climate change caused by?
answer
Carbon levels
question
How much carbon you used in your lifetime
answer
Carbon footprint
question
Atmospheric carbon contributes to what?
answer

Greenhouse effect

acid rain

question

Causes breakdown of coral reefs

pH of oceans will affect this a lot

Acid rain on mountain tops; ruins soil and causes trees to dry out and die

answer
Acidification
question
What is a source of local acidification?
answer
Acid mine drainage. Water that comes through them becomes polluted and pollutes water sources. This kills fish, microinvertabrates, causes dead patches in streams
question
What must both drinking water and sewage water undergo before going back into the system?
answer
Chlorination
question
Excess nitrates (NO2) and sulfates (SO2) cause pollution. What type of pollution is this?
answer
Sulfur pollution
question
Excess nutrients are feeding microbes and large algal blooms are created. WHen they die cause excess organic material to collect on the bottom
answer
Dead zones
question
Level of O2 in water that will sustain life
answer
BOD
question
Make low pH water neutral pH once it gets through system. Microorganisms in the shallow water and muck use anaerobic metabolism use alternate electron acceptors such as nitrate/sulfate
answer
Buffer zones
question

Uses a muck sample to analyze for microorganisms

Compares sulfur oxidation, photosynthesis, etc

Put in muck, sulfur sample, and pond water

Anaerobes at bottom photosynthesizers at top

2-3 months incubation

answer
Winogradiski Column
question
Helps to clean up pollution naturally using microbes. Reduce PCB's and TCE (Known carcinogens)
answer
Bioremediation
question
Have to be careful that microbes released wont affect other organisms. These unintended effects are known as what?
answer
Non-target effects
question
What species are pivotal in the cleaning up of oil spills?
answer
Pseudomonas
question
During this process, organic compounds are converted to inorganic compounds
answer
Mineralization
question
Microbes release what substance?
answer
Nitrogen
question
Beginning of nitrogen cycle. Breakdown of dead and decaying material into ________.
answer
Ammonification; ammonia
question
What is broken down into ammonia during ammonification?
answer
Urea
question
Second step of nitrogen cycle following ammonification. It is a 2 step process. Converts ammonia to nitrite and then nitrite to nitrate
answer
Nitrification
question
During the first step of nitrification; what happens? And what species carry it out?
answer

Ammonia to nitrite.

Nitrosococcus

Nitrosomonas

question
During the second step of nitrification; what happens? What species are responsible?
answer

Nitrite to nitrate

 

Nitrococcus

Nitrobacter

question

Third step of nitrogen cycle following nitrification.

 

Involves taking nitrate to nitrogen gas. This replenishes the atmosphere

answer
Denitrification
question
What species carries out denitrification?
answer
Pseudomonas
question
What is the bad greenhouse gas that can be given off by denitrification?
answer
Nitris oxide
question
Taking nitrogen gas and converting it to organic nitrogen.
answer
Nitrogen fixation
question
What species carries out nitrogen fixation?
answer
Rhizobium (bacteria) Legumes, clover have pockets called nodules (located in roots) that contain this.
question
Fungal symbiotic relationships with plant roots. Make plants more efficient in absorbing nutrients
answer
Mycorrhizae
question
Plant pathogen (bacteria) that causes tumor to form by horizontal gene transfer. The bacteria affects DNA in plants (bacterial DNA found in nucleoid region) creates pili between bacteria and plant cell. Will express virulent DNA which produces massive growth in tissue.
answer
Agrobacterium
question
What does virulent DNA that causes tumor growth in plants produce that is helpful to harmful bacteria?
answer
Opines
question
Scientific model for GMO's Do experiments on this much like we test meds on mice
answer
Arabidopsis Thalliana
question
What is the photosynthetic part that plants possess?
answer
Chloroplasts
question
What was the first photosynthesis carried out by?
answer
Cyanobacteria
question
How many phases does photosynthesis have? And what are they?
answer
2 phases; light and dark
question
In this phase of photosynthesis; plant absorbs energy from the sun. Shifts around electrons through an ETC. NADPH and ATP created travel to calvin cycle. CO2 fixed into larger carbohydrate and releases O2
answer
Light cycle
question
What is created in the light phase of photosynthesis?
answer
NADPH and ATP
question
In this phase of photosynthesis, CO2 is incorportaed into sugar. Energy from other phase drives this
answer
Dark phase
question
One celled euk. photosynthesizers
answer
Algae
question
What do photosynthetic bacteria have?
answer
Thylakoids
question
This is found with cyanobacteria in marine ecosystems
answer
microalgae
question
Zoo plankton. Symbiotic relationships between larger animals that provide nutrients heterotrophic or photosyntheic
answer
Zooxanthaellae
question
Biological phenomenon that indicates growth in response to an environmental stimulus
answer
Tropism
question
Tiny organism that lives within dinoflagellates
answer
Roseobacter clade
question
What does the sulfur smell of the ocean come from? Other ocean smell?
answer
Dinoflagellates. DMSP
question
In earthworm group. Live near hydrothermal vents where no sunlight is present. Surround water is very cold but vents are very warm
answer
Hydrothermal vent tube worms
question
Have no digestive system. Have a symbiotic relationship with bacteria that live in trophosomes and feed them. Discovered by Colleen Cavanaugh
answer
HTV Tube worms
question
Only eat wood (carbon/cellulose) have many bacteria/archea/protists that help it digest it and allow them to use it as a nutrient source. Contain nitrogen fixing bacteria that converts nitrogen gas to organic nitrogen
answer
Termites
question
Complex parasitic euk. that wouldnt be symbiotic without bacteria.
answer
Nematodes
question
C. elegans is what?
answer
Eukaryotic cell model; behave similarily to human cells
question
When using bio control, we want to consider these because their effects are often much more damaging than predator-prey interactions
answer
Nematodes
question
HB bacteria interacts with these. Live inside them and fluoresce. Virulent bacteria that kills caterpillars in 24-48 hours.
answer
Nematodes
question
An association between a fungal mycelium and a cyanobacterium or alga
answer
Lichens
question
Lichens are composed of what 2 organisms?
answer
Fungi and cyanobacteria
question
Where do lichens grow? What do they replenish? What are they good indicators of?
answer
Rock and stone. Break them down into soil. They replenish soil. Good indicators of pollution because they do not grow well in areas that are highly polluted.
question
Microbes that glow are said to what?
answer
Bioluminesce
question
Sea water vibrio that helps squid to glow because of the light this bacteria gives off. Helps the squid to appear to be a part of the night sky when the predators look up at it. Camo!
answer
Vibrio Fischeri
question
"Cud chewers" cows, sheep, deer. 4 chambers to stomach. Regurgitate food and chew again
answer
Ruminants
question
If the diets of ruminants are changed suddenly, what can affect them that is potentially fatal?
answer
Acidosis
question
In humans these form a symbiotic relationship
answer
Gut microbiota
question
An interrelationship between 2 populations of organisms where there is a close and permanant association
answer
Symbiosis
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New