MICR-4070 Lecture Notes - Lecture 13: Magnetic Ink Character Recognition, Microbiology, Gram-Positive Bacteria

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12 Mar 2018

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Micr 4070: food and dairy microbiology test 2 (lecture 4, physical methods of preservation) As the temperature increases, microbial death also increases. A different time and temperature will result in a different t value. E. coli (gram negative, rods) are much less heat resistant than gram positive bacteria. Spore formers are more resistant than non-spore formers. Thermophilic bacteria are more heat resistant than mesophiles like clostridium botulinum. Anaerobic sporeformers are more heat resistant than aerobic microorganisms. Food products rich in meat or fat are more resistant and need more heat treatment. More heat transfer will occur in a slice of meat. Low heat processing <100 c: finished products are not sterile but there is a smaller population: some enzymes of foods will be destroyed. Friday, march 16, 2018: food quality is preserved, thermoduric cells of spoilage organisms and spores will survive, heat stable enzymes and toxins will survive.

Related Questions

What are the correct answers to the parts of this quiz marked incorrect? (that is my one question. Please take your time. I value accuracy over speed. )

IncorrectQuestion 2

0 / 1 pts
Studies done by Buchner showed that ground-up yeast cells were able to convert sugar to alcohol. The components of the mixture that were responsible for this transformation were

DNA molecules.

enzymes.

lipids.

carbohydrates.

Bloom's Level: 2. Understand
Learning Outcome: 06.01
Section: 06.01
Topic: History of Microbiology

IncorrectQuestion 3
0 / 1 pts
Bacteria that can absorb light energy and convert it into ATP are commonly called

cytochromes.

lysosomes.

chemotrophs.

phototrophs.

cytochromes AND chemotrophs.

Bloom's Level: 1. Remember
Learning Outcome: 06.02
Section: 06.01
Topic: Microbial Metabolism

IncorrectQuestion 4
0 / 1 pts
The readily usable energy currency of cells is

electricity.

the electron transport system.

ATP.

CTP.

the electron transport system AND CTP.

Bloom's Level: 1. Remember
Learning Outcome: 06.02
Section: 06.01
Topic: Microbial Metabolism

IncorrectQuestion 5
0 / 1 pts
NAD in its reduced form is symbolized as

NADH.

NAD.

NAD-.

NADP.

Bloom's Level: 1. Remember
Learning Outcome: 06.03
Section: 06.01
Topic: Microbial Metabolism

IncorrectQuestion 6
0 / 1 pts
The most common starting pathway for the breakdown of sugars is

respiration.

fermentation.

glycolysis.

oxidation.

Bloom's Level: 2. Understand
Learning Outcome: 06.04
Section: 06.01
Topic: Microbial Metabolism

IncorrectQuestion 7
0 / 1 pts
Which of the following processes generates the greatest amount of energy?

fermentation

aerobic respiration

the Entner-Duodoroff pathway

glycolysis

fermentation AND the Entner-Duodoroff pathway

Bloom's Level: 2. Understand
Learning Outcome: 06.05
Section: 06.01
Topic: Microbial Metabolism

IncorrectQuestion 8
0 / 1 pts
Fermentation

uses an inorganic molecule as the final electron acceptor.

uses an organic molecule as the final electron acceptor.

results in the production of a large amount of ATP.

is necessary in some organisms to produce reduced electron carriers.

uses an organic molecule as the final electron acceptor AND is necessary in some organisms to produce reduced electron carriers.

Bloom's Level: 2. Understand
Learning Outcome: 06.05
Section: 06.01
Topic: Microbial Metabolism

IncorrectQuestion 9
0 / 1 pts
The use of the suffix "ase" on a word denotes a(n)

substrate.

product.

enzyme.

electron acceptor.

substrate AND electron acceptor.

Bloom's Level: 1. Remember
Learning Outcome: 06.06
Section: 06.02
Topic: Microbial Metabolism

IncorrectQuestion 10
0 / 1 pts
Enzymes speed up reactions by

raising activation energy.

producing heat.

reducing entropy.

lowering activation energy.

raising activation energy AND reducing entropy.

Bloom's Level: 2. Understand
Learning Outcome: 06.06
Section: 06.02
Topic: Microbial Metabolism

IncorrectQuestion 11
0 / 1 pts
Most enzymes

are generalists and typically recognize a number of different substrates.

are specialists and typically recognize a single substrate.

are active over a wide pH range.

have several active sites.

are generalists and typically recognize a number of different substrates AND have several active sites.

Bloom's Level: 2. Understand
Learning Outcome: 06.06
Section: 06.02
Topic: Microbial Metabolism

IncorrectQuestion 12
0 / 1 pts
Allosteric enzymes

may bind two substrates.

are used to bind to other enzymes.

have an additional binding site that is involved in regulating enzyme activity.

are twice as fast as single site enzymes.

may bind two substrates AND are twice as fast as single site enzymes.

Bloom's Level: 2. Understand
Learning Outcome: 06.09
Section: 06.02
Topic: Microbial Metabolism

Question 13
1 / 1 pts
Feedback inhibition

is a means of regulating the amount of product produced.

often involves the use of allosteric enzymes.

involves inhibiting the last of a series of reactions.

results in raising the activation energy for the reaction.

is a means of regulating the amount of product produced AND often involves the use of allosteric enzymes.

Bloom's Level: 2. Understand
Learning Outcome: 06.10
Section: 06.02
Topic: Microbial Metabolism

IncorrectQuestion 14
0 / 1 pts
Coenzymes are derivatives of

minerals.

proteins.

lipids.

vitamins.

Bloom's Level: 1. Remember
Learning Outcome: 06.07
Section: 06.02
Topic: Microbial Metabolism

Question 15
1 / 1 pts
Environmental factors that may affect enzyme activity include

temperature

pH

salt

age

temperature, pH AND salt

Bloom's Level: 2. Understand
Learning Outcome: 06.08
Section: 06.02
Topic: Microbial Metabolism

Question 16
1 / 1 pts
Most enzymes function best at

acidic pH and high salt concentrations.

basic pH and low salt concentrations.

neutral pH and high salt concentrations.

slightly above pH 7 and low salt concentrations.

Bloom's Level: 2. Understand
Learning Outcome: 06.08
Section: 06.02
Topic: Microbial Metabolism

Question 17
1 / 1 pts
Mercury in mercurochrome inhibits growth

through competitive inhibition.

through a reversible action.

by oxidizing the sulfhydryl groups in cysteine.

by changing the shape of proteins.

by oxidizing the sulfhydryl groups in cysteine AND by changing the shape of proteins.

Bloom's Level: 3. Apply
Learning Outcome: 06.10
Section: 06.02
Topic: Microbial Metabolism

IncorrectQuestion 18
0 / 1 pts
The term precursor metabolite refers to molecules that

activate cell components.

are used in biosynthesis.

result from cell activities.

are present but inactive.

Bloom's Level: 2. Understand
Learning Outcome: 06.11
Section: 06.03
Topic: Microbial Metabolism

IncorrectQuestion 19
0 / 1 pts
Glycolysis

requires oxygen.

produces 3 ATP molecules.

produces 4 molecules of NAD.

may occur under aerobic or anaerobic conditions.

produces 3 ATP molecules AND produces 4 molecules of NAD.

Bloom's Level: 2. Understand
Learning Outcome: 06.12
Section: 06.03
Topic: Microbial Metabolism

IncorrectQuestion 20
0 / 1 pts
The transition step

links glycolysis to the pentose phosphate pathway.

links the pentose phosphate pathway to the Entner-Duodoroff pathway.

links glycolysis to the TCA cycle.

takes place in the matrix of the nucleus.

Bloom's Level: 1. Remember
Learning Outcome: 06.11
Section: 06.03
Topic: Microbial Metabolism

Question 21
1 / 1 pts
The TCA cycle produces

ATP through substrate-level phosphorylation.

NADH.

FADH2.

precursor metabolites.

All of the choices are correct.

Bloom's Level: 1. Remember
Learning Outcome: 06.12
Section: 06.03
Topic: Microbial Metabolism

Question 22
1 / 1 pts
The electron transport system

requires a membrane.

utilizes the nuclear membrane of eukaryotes.

utilizes the mitochondrial membrane of prokaryotes.

generates a concentration gradient of protons.

requires a membrane AND generates a concentration gradient of protons.

Bloom's Level: 2. Understand
Learning Outcome: 06.13
Section: 06.04
Topic: Microbial Metabolism

IncorrectQuestion 23
0 / 1 pts
Which type of phosphorylation does not require a membrane?

Substrate-level phosphorylation

Oxidative phosphorylation

Photophosphorylation

All types of phosphorylation require a membrane.

Bloom's Level: 2. Understand
Learning Outcome: 06.13
Section: 06.04
Topic: Microbial Metabolism

Question 24
1 / 1 pts
Which pairing is incorrect?

A:T

G:C

A:U

A:G

Bloom's Level: 3. Apply
Learning Outcome: 07.01
Section: 07.01
Topic: Genetics

Question 25
1 / 1 pts
RNA is characterized by which one of the following features?

Deoxyribose.

Thymine.

Ribose.

Double-stranded.

Bloom's Level: 1. Remember
Learning Outcome: 07.01
Section: 07.01
Topic: Genetics

Question 26
1 / 1 pts
DNA is characterized by which of the following feature(s)?

Ribose.

Single-stranded.

Deoxyribose.

Thymine.

Deoxyribose AND thymine.

Bloom's Level: 1. Remember
Learning Outcome: 07.01
Section: 07.01
Topic: Genetics

Question 27
1 / 1 pts
Which of the following is/are true of DNA replication?

It starts at the origin of replication.

Nucleotides are added to the 3' end.

It requires an RNA primer to get started.

It utilizes polymerases.

All of the choices are true.

Bloom's Level: 2. Understand
Learning Outcome: 07.03
Section: 07.02
Topic: Genetics

Question 28
1 / 1 pts
Which is true about the RNA transcript?

It is formed using the DNA minus strand as a template.

It has the same 5'-3' orientation as the DNA positive strand.

It is made in short fragments that are then stitched together.

The template starts at the promoter region.

It is formed using the DNA minus strand as a template, it has the same 5'-3' orientation as the DNA positive strand AND the template starts at the promoter region.

Bloom's Level: 2. Understand
Learning Outcome: 07.04
Section: 07.03
Topic: Genetics

IncorrectQuestion 29
0 / 1 pts
How many nucleotides are in a codon?

1

2

3

4

5

Bloom's Level: 1. Remember
Learning Outcome: 07.05
Section: 07.03
Topic: Genetics

Question 30
1 / 1 pts
Which may be or is an RNA molecule?

AGCCTAC

GGGCCCA

GCCCUUA

AGCCTAC AND GGGCCCA

GGGCCCA AND GCCCUUA

Bloom's Level: 2. Understand
Learning Outcome: 07.01
Section: 07.01
Topic: Genetics

IncorrectQuestion 31
0 / 1 pts
Which molecule carries an anticodon?

DNA

mRNA

rRNA

tRNA

Bloom's Level: 1. Remember
Learning Outcome: 07.05
Section: 07.03
Topic: Genetics

Question 32
1 / 1 pts
AUG

is only used as the start codon.

codes for methionine.

determines the reading frame.

is one of the stop codons.

codes for methionine AND determines the reading frame.

Bloom's Level: 2. Understand
Learning Outcome: 07.05
Section: 07.03
Topic: Genetics

IncorrectQuestion 33
0 / 1 pts
The A-site

is found on the RNA polymerase enzyme.

is found on the 30S ribosome.

is found on the 70S ribosome.

is the amino acid site.

is found on the 70S ribosome AND is the amino acid site.

Bloom's Level: 1. Remember
Learning Outcome: 07.05
Section: 07.03
Topic: Genetics

IncorrectQuestion 34
0 / 1 pts
A stop codon

codes for the stop amino acid s-methyl-methionine.

forms a hairpin loop forcing the ribosome to fall off.

codes for no amino acid.

enhances the binding of the e-polymerase.

codes for the stop amino acid s-methyl-methionine AND forms a hairpin loop forcing the ribosome to fall off.

Bloom's Level: 2. Understand
Learning Outcome: 07.05
Section: 07.03
Topic: Genetics

IncorrectQuestion 35
0 / 1 pts
Some segments of the precursor mRNA in eukaryotes are non-coding and are called

exons.

introns.

integrans.

uselessans.

Bloom's Level: 1. Remember
Learning Outcome: 07.06
Section: 07.04
Topic: Genetics

Question 36
1 / 1 pts
Gene regulation may entail

turning on genes only when needed.

turning off genes when not needed.

turning on or off entire groups of genes.

All of the choices are correct.

Bloom's Level: 2. Understand
Learning Outcome: 07.09
Section: 07.06
Topic: Genetics

IncorrectQuestion 37
0 / 1 pts
The set of genes in bacteria that are linked together and transcribed as a single unit is referred to as a(n)

operon.

regulon.

operator.

repressor.

Bloom's Level: 1. Remember
Learning Outcome: 07.09
Section: 07.06
Topic: Genetics

Question 38
1 / 1 pts
The molecules that bind to a repressor and cause it to no longer bind to the operator are called

activators.

repressors.

introns.

inducers.

Bloom's Level: 2. Understand
Learning Outcome: 07.09
Section: 07.06
Topic: Genetics

Question 39
1 / 1 pts
Repressors

are involved in negative control.

are involved in positive control.

always bind to the promoter.

bind or do not bind to the operator depending on their shape (conformation).

are involved in negative control AND bind or do not bind to the operator depending on their shape (conformation).

Bloom's Level: 2. Understand
Learning Outcome: 07.09
Section: 07.06
Topic: Genetics

Question 40
1 / 1 pts
Activators

are involved in negative control.

are involved in positive control.

always bind to the promoter.

are allosteric proteins.

are involved in positive control AND are allosteric proteins.

Bloom's Level: 2. Understand
Learning Outcome: 07.09
Section: 07.06
Topic: Genetics

Question 41
1 / 1 pts
Signal transduction

is the relay of information about conditions outside a cell to inside the cell.

often relies on a two component system.

may involve phosphorylation of various molecules.

is used by certain pathogens to sense low magnesium conditions.

All of the choices are correct.

Bloom's Level: 2. Understand
Learning Outcome: 07.07
Section: 07.05
Topic: Genetics

IncorrectQuestion 42
0 / 1 pts

Quorum sensing

is used by bacteria to sense the density of cells.

is used by bacteria to sense the proximity of eukaryotic cells

is used by bacteria to limit the density of cells.

is used by eukaryotes to sense the presence of bacteria.

does not influence the expression of genes by a bacteria.

Quorum sensingBloom's Level: 2. UnderstandLearning Outcome: 07.07Section: 07.05Topic: Genetics

Question 43
1 / 1 pts
In DNA sequence analysis

the + strand of DNA is used.

the start codon is ATG.

ORFs are searched for.

codon usage is a helpful indicator for protein coding areas.

All of the choices are correct.

Bloom's Level: 2. Understand
Learning Outcome: 07.12
Section: 07.08
Topic: Genetics

IncorrectQuestion 44
0 / 1 pts
DNA replication is usually unidirectional.

True

False

Bloom's Level: 2. Understand
Learning Outcome: 07.03
Section: 07.02
Topic: Genetics

IncorrectQuestion 45
0 / 1 pts
There are 4 functional types of RNA.

True

False

Bloom's Level: 1. Remember
Learning Outcome: 07.04
Section: 07.03
Topic: Genetics

Question 46
1 / 1 pts
Antisense RNA is the complement of the plus strand and may be useful in inhibiting translation.

True

False

Bloom's Level: 2. Understand
Learning Outcome: 07.11
Section: 07.07
Topic: Genetics

IncorrectQuestion 47
0 / 1 pts
A drug that inhibits the activity of bacterial DNA gyrase ______ be a good antibiotic because _______.

would; it would inhibit all DNA synthesis

would NOT; it would inhibit all DNA synthesis, even our own cell's DNA synthesis

would; it would selectively inhibit bacterial DNA synthesis due to differences between bacterial/human gyrase

would NOT; the DNA replication machinery could still function, even with impaired DNA gyrase enzyme

Bloom's Level: 5. Evaluate
Learning Outcome: 07.03
Section: 07.02
Topic: Genetics

IncorrectQuestion 48
0 / 1 pts
The regulatory protein

binds to the promoter region of DNA.

may inhibit or enhance transcription.

may control translation of the operon.

affects the activity of the DNA polymerase.

binds to the promoter region of DNA AND affects the activity of the DNA polymerase.

Bloom's Level: 2. Understand
Learning Outcome: 07.09
Section: 07.06
Topic: Genetics

Question 49
1 / 1 pts
The source of variation among microorganisms that were once identical is

antibiotic resistance.

virulence factors.

sigma factors.

mutation.

Bloom's Level: 1. Remember
Learning Outcome: 08.02
Section: 08.01
Topic: Genetics

Question 50
1 / 1 pts
The characteristics displayed by an organism in any given environment is its

genotype.

archaetype.

mutatotype.

phenotype.

Bloom's Level: 2. Understand
Learning Outcome: 08.01
Section: 08.01
Topic: Genetics

Question 51
1 / 1 pts
Transposons

are informally known as jumping genes.

may cause insertion mutations.

may cause knockout mutations.

were first recognized in plants.

All of the choices are correct.

Bloom's Level: 2. Understand
Learning Outcome: 08.05
Section: 08.02
Topic: Genetics

Question 52
1 / 1 pts
The largest group of chemical mutagens consists of

radiation.

base analogs.

nitrous acid.

alkylating agents.

Bloom's Level: 1. Remember
Learning Outcome: 08.06
Section: 08.03
Topic: Genetics

Question 53
1 / 1 pts
Nitrous acid most frequently causes mutations by

substituting oxygen for hydrogen bonds.

converting keto groups to amino groups.

altering the bonding ratios of nitrogen bases.

converting cytosine to uracil.

Bloom's Level: 2. Understand
Learning Outcome: 08.06
Section: 08.03
Topic: Genetics

IncorrectQuestion 54
0 / 1 pts
Chemical mutagens that mimic the naturally occurring bases are called

nitrogen mustards.

alkylating agents.

base analogs.

nitrous oxide.

Bloom's Level: 1. Remember
Learning Outcome: 08.06
Section: 08.03
Topic: Genetics

IncorrectQuestion 55
0 / 1 pts
Irradiation of cells with ultraviolet light may cause

4 nucleotides to covalently bind together.

thymine dimers.

adenine complementary base pairing with cytosine.

the addition of uracil.

Bloom's Level: 2. Understand
Learning Outcome: 08.08
Section: 08.03
Topic: Genetics

Question 56
1 / 1 pts
Thymine dimers are dealt with by

no repair mechanisms.

photoreactivation repair.

SOS repair.

excision repair.

photoreactivation repair AND excision repair.

Bloom's Level: 2. Understand
Learning Outcome: 08.11
Section: 08.04
Topic: Genetics

IncorrectQuestion 57
0 / 1 pts
X-rays

have no effect on DNA.

cause thymine trimers.

cause single and double strand breaks in DNA molecules.

make the DNA radioactive.

Bloom's Level: 1. Remember
Learning Outcome: 08.08
Section: 08.03
Topic: Genetics

IncorrectQuestion 58
0 / 1 pts
DNA repair mechanisms occur

only in prokaryotes.

only in eukaryotes.

in both eukaryotes and prokaryotes.

in neither eukaryotes or prokaryotes.

Bloom's Level: 1. Remember
Learning Outcome: 08.09
Section: 08.04
Topic: Genetics

IncorrectQuestion 59
0 / 1 pts
Antibiotics

cause mutations to occur.

may act as alkylating mutagens.

provide an environment in which pre-existing mutants survive.

increase the rate of spontaneous mutation.

Bloom's Level: 2. Understand
Learning Outcome: 08.12
Section: 08.05
Topic: Genetics

IncorrectQuestion 60
0 / 1 pts
Prokaryotic cell mutations can be observed very quickly because the prokaryotic chromosome is

diploid.

polyploid.

haploid.

polysomal.

Bloom's Level: 2. Understand
Learning Outcome: 08.02
Section: 08.01
Topic: Genetics

Question 61
1 / 1 pts
The diploid character of eukaryotic cells may mask the appearance of a mutation since

this may be a frame shift.

the mutation is often reversible.

the mutation may be palindromic.

the matching chromosome may carry the dominant gene.

Bloom's Level: 2. Understand
Learning Outcome: 08.02
Section: 08.01
Topic: Genetics

IncorrectQuestion 62
0 / 1 pts
A clever technique that streamlines the identification of auxotrophic mutants is

gas chromatography.

replica plating.

direct selection.

reversion.

Bloom's Level: 2. Understand
Learning Outcome: 08.12
Section: 08.05
Topic: Genetics

IncorrectQuestion 63
0 / 1 pts
To increase the proportion of mutants in a population of bacteria one may use

direct selection.

replica plating.

penicillin enrichment.

individual transfer.

Bloom's Level: 2. Understand
Learning Outcome: 08.12
Section: 08.05
Topic: Genetics

Question 64
1 / 1 pts
Bacteria that have properties of both the donor and recipient cells are the result of

UV light.

SOS repair.

frame shift mutations.

genetic recombination.

Bloom's Level: 2. Understand
Learning Outcome: 08.13
Section: 08.06
Topic: Genetics

IncorrectQuestion 65
0 / 1 pts
The mechanism by which genes are transferred into bacteria via viruses is called

ellipsis.

replica plating.

transformation.

transduction.

conjugation.

Bloom's Level: 1. Remember
Learning Outcome: 08.14
Section: 08.07
Topic: Genetics

IncorrectQuestion 66
0 / 1 pts
In conjugation the donor cell is recognized by the presence of

an F plasmid.

a Y chromosome.

diploid chromosomes.

an SOS response.

an F plasmid AND diploid chromosomes.

Bloom's Level: 2. Understand
Learning Outcome: 08.15
Section: 08.08
Topic: Genetics

IncorrectQuestion 67
0 / 1 pts
Gene transfer that requires cell-to-cell contact is

transformation.

competency.

conjugation.

functional genomics.

Bloom's Level: 2. Understand
Learning Outcome: 08.15
Section: 08.08
Topic: Genetics

Question 68
1 / 1 pts
The transfer of vancomycin resistance from Enterococcus faecalis to Staphylococcus aureus is thought to have involved

conjugation.

transformation.

transduction.

transposons.

conjugation AND transposons.

Bloom's Level: 2. Understand
Learning Outcome: 08.17
Section: 08.09
Topic: Genetics

IncorrectQuestion 69
0 / 1 pts
Double-stranded DNA enters the recipient cell during transformation.

True

False

Bloom's Level: 2. Understand
Learning Outcome: 08.13
Section: 08.06
Topic: Genetics

Question 70
1 / 1 pts
Plasmids often carry the information for antibiotic resistance.

True

False

Bloom's Level: 2. Understand
Learning Outcome: 08.16
Section: 08.09
Topic: Genetics

Quiz Score: 31 out of 70

Review Questions for Chapter 5: Control of Microbial Growth

1. Consider the following statement: âThorough handwashing with soap and water is the most important step in stopping the spread of many infectious diseasesâ.

a. Explain this statement.

b. Following thorough handwashing with soap, are your hands sterile? Why or why not?

2. If pasteurization does not achieve sterilization, why is pasteurization used to treat food? Why not just heat the food instead?

3. Consider the use of salts and sugars to preserve food.

a. How do salts and sugars preserve foods?

b. Why are these considered physical rather than chemical methods of microbial control?

c. Name one food that is preserved with sugar and one preserved with salt.

d. How do you account for the occasional growth of Penicillium mold in jelly, which is 50% sucrose?

4. Consider dried fruit you can buy at the store (e.g., raisins, pineapples, figs, dates, etc.) Dried fruits date back thousands of years B.C.

a. Why is this such an effective method of preserving food? Suggest several possibilities.

b. Fruit is often dried by being placed outside in the open under the sun in conditions that are not exactly sanitized. Why is this practice generally very safe?

5. There is great concern over healthcare-associated infections.

a. Why are healthcare settings such a âgoodâ place to catch infectious diseases? List several reasons.

b. What are several effective approaches that healthcare settings can take to minimize the spread of infectious disease?

6. Flying on an airplane includes lots of individuals in close quarters for potentially long periods of time.

a. What technology do you think airplanes use to reduce the amount of microbes from the air?

b. Despite this control method, there have been a number of documented cases of individuals infected with tuberculosis infecting other passengers during a flight. Explain how you think this happened. Which patients are at highest risk for infection, and what does this tell you about the effectiveness of microbial control on an airplane?

7. The thermal death time for a suspension of Bacillus subtilis endospores is 20 minutes in dry heat and less than 10 minutes in an autoclave. Which type of heat is more effective? Why?

8. A large hospital washes burn patients in a stainless steel tub. After each patient, the tub is cleaned with a quat. It was noticed that 14 of 20 burn patients acquired Pseudomonas infections

after being bathed. Provide an explanation for this high rate of infection.

9. If youâre on a municipal water supply, the water coming out of your faucet is chlorinated at the water treatment plant.

a. Is the water coming out of your faucet sterile?

b. Does the water still contain chlorine?

c. What are advantages and disadvantages of chlorine compared with other approaches (e.g., UV treatment, treatment with ozone).

10. You are a member of Engineers Without Borders, and your local chapter has been asked by a rural village in Thailand to assist them with improving their water supply, which they suspect of making villagers sick. The village has piping infrastructure that delivers water through a series of pipes to each household. Upon your initial site assessment of the village, you and your team determine that the water has high turbidity (particulate material) as well as a high bacterial count.

a. Design a strategy for treating the water to make it safe to drink that still relies upon the distribution system. Note that you may make some reasonable assumptions about conditions in the village (e.g., availability of electricity if you wish).

b. Identify some possible limitations of your approach.

11. A low technology approach to treating water in rural locations is to fill clear plastic soda bottles with water and leave it out all day in the sun (e.g., up on a roof).

a. What two factors are most likely at work in controlling microbes in these conditions?

b. What impact does each factor have on the microbes? Be specific.

amberraven287

BIOTECHNOLOGY

Introduction

In this Experiment we will learn how to identify the unknownbacterium according to the case study given as you start to performyour procedures and following the steps. Also, we will be learningthe outcome of a specific case scenario of immunity. We will beperforming different examples of media and observing the reactionafter inoculation and adding different reagents as it produce somechanging of color diagnose to a negative or positive results. Also,we will conduct different types of biochemical testing includingIndole production, Citrate Utilization, Methyl red test, andMannitol Fermentation.

In this case scenario we are trying to figure out theinfestation of food at the warehouse causing a death of theplaintiff mother. The plaintiff is accusing the warehouse forselling these infested products by insects. At the warehouseinspection is been done by swabbing and acquiring the type oforganism to be identified as evidence for the court finaldecision.

One of the major findings in this experiment is that itwas negative gram stains and the Indole and Methyl Red Test had apositive reaction. Additional testing was perform which show theresult of only negative on Lactose Fermentation and the remainingthree additional testing add up to a positive. The outcome of thisinvestigation scenario could be a negative result to the casescenario presented about infested products by insects since nounknown bacteria was left to bediagnosed.

Procedure

The following steps are requiring completing this labexperimental. First make sure you open the Virtual UnknownSoftware. Complete conducting using Indole production and CitrateUtilization, Methyl Red test choosing from your media option. Alsomake sure you open the reference book for each procedure to beinformed of the lab steps and decision making such as positive ornegative and its color after inoculation.

Observations and Results

	Result + or -	Appearance after Incubation
Gram Stain	- gram rods	N/A
Indole Production	+ positive	Yellowish-after incubation & adding Kovacâs reagent changingto a cherry red color indication of positive
Mannitol Fermentation	- neg	Red
Methyl Red Test	+ pos	Turbid yellowish after incubation and adding methyl red reagentchange to red positive. +
Citrate Utilization	- neg	Greenish after incubation. No reagent added.

Additional tests performed are listed below:

	Result + or -	Appearance after Incubation
Lactose Fermentation	- neg	Red- no reagent added
Sucrose Fermentation	+ pos	Yellowish- no reagent added
Phenol Red Rhamnose (Lactose Steps)	+ pos	Yellow- no reagent
Phenol Red Xylose (Sucrose Steps)	+ pos	Yellow- no reagent

Bacterium identified as: You may want to do some additionaltests to conclusively identify your bacterium. Some good ones to domight be lactose and sucrose fermentation, like you did last week.Remember, they use Phenol Red Lactose Broth and Phenol RedSucrose Broth and yellow= positiveand red =negative. After you do those two tests,you may want to do Phenol Red Rhamnose and Phenol RedXylose, which are set up the same way as the sucrose andlactose tests, they just have different sugars. Be sure to recordyour test results!

Discussion

Identify the bacterium â Make sure you look in the VirtualUnknown lab report to make sure you got the right organism. Afteryou have made your identification, look at the lab report. You cando this by going to the View menu in Virtual Unknown and selectingLab Report. You can double check with me that you are researchingthe right one.

Once all observation was performed including the additionaltesting I was left without an Unknown organism to be identified.This only leave me with a diagnose to state that no evidence wascollected to accused the warehouse as being infested with insectsaccording to the case study.

Explain what features of this organism make it an idealcandidate host for your insecticide. (Hint: remember you will needto infect insects with the bacteria to deliver the insecticide.)âFind out where the unknown organism was isolated from.

Describe in detail the steps you will take to insert the targetgene into the bacterium. - Figure 8.1 of your book should help youwith this.

Conclusion

< Within a few sentences, provide a concluding statementabout the results of your laboratory>

Virtual Lab Report

Student:

Instructor: Test User

Section:

Unknown: BiotechUnknown

Identification Information

Assigned Unknown: Identification not yet complete

Identified Unknown: TBD

Gram Reaction & Morphology: Gram Negative Rods

Auto-Inoculation Used: Yes

Test Detail (Chronological Order):

1 Gram Reaction {-} Eliminated {53}Remaining {71} Recorded 1 time(s)

Observations: none

2 Indole production {+} Eliminated {44}Remaining {27} Recorded 1 time(s)

Observations: none

3 Mannitol fermentation {-} Eliminated {19}Remaining {8} Recorded 1 time(s)

Observations: none

4 Methyl red {+} Eliminated {0} Remaining{8} Recorded 1 time(s)

Observations: none

5 Citrate Utilization (Simmons) {-}Eliminated {2} Remaining {6} Recorded 1 time(s)

Observations: none

6 Lactose fermentation {-} Eliminated {0}Remaining {6} Recorded 1 time(s)

Observations: none

7 Sucrose fermentation {+} Eliminated {4}Remaining {2} Recorded 1 time(s)

Observations: none

8 Rhamnose fermentation {+} Eliminated {2}Remaining {0} Recorded 1 time(s)

Observations: none

9 Xylose fermentation {+} Eliminated {0}Remaining {0} Recorded

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MICR-4070 Lecture Notes - Lecture 13: Magnetic Ink Character Recognition, Microbiology, Gram-Positive Bacteria

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