Microbiology Final

What is the starting substrate for the Krebs cycle?

Acetyl-CoA

The molecule serving as mRNA can be incorporated in the newly synthesized virus capsids of all of the following except

- strand RNA rhabdoviruses.

Endotoxin

-Lipid A -Heat resistant -Usually mild effect on host -Gram - bacteria only - Pyrogenic

Pili

-Motility -Transfer of genetic material

. If an animal cell (unprotected by a cell wall) is placed in a hypertonic environment the following would result

there would be a net loss of water out of the cell and the cell would die

If a bacterial cell with an intact cell wall is placed in a hypertonic environment the following would result

there would be a net loss of water out of the cell and the cell would die

Assume that you are viewing a Gram-stained field of red cocci and blue rods through the microscope. You can safely conclude that you have

two different species

respiration is the utilization of an electron transport chain. The chief purpose of an electron transport chain is to

use the energy in electrons to move hydrogen ions to a higher concentration

If you had just one cell of E. coli O157:H7 in hamburger meat and you performed PCR on this sample and went only 10 cycles, how many copies of the specified DNA would you have?

1024

Fill in the following blanks. 1 μm = _____m 1 ______= 10-9 m 1 μm = ______nm

1026 m 1 nm 103 nm

Calculate the total magnification of the nucleus of a cell being observed through a compound light microscope with a 10× ocular lens and an oil immersion lens.

10X (Lens) x 100X (oil)= 1000x

Which one of the following temperatures would most likely kill a mesophile?

60 Degrees Celsius

a good antiseptic would be?

70% solution of alcohol

A pastry chef accidentally inoculated a cream pie with six S. aureus cells. If S. aureus has a generation time of 60 minutes, how many cells would be in the cream pie after 7 hours?

768

The synthetic anti viral drug, AZT was one of the first treatments to be used against HIV. This reagent is analog of ATP and is thus a competitive inhibitor of the enzyme reverse transcriptase. AZT can be best described as a

synthetic chemotherapeutic agent

a bacterial cell placed in a hypotonic solution will

take on some water but will be protected from bursting by the cell wall

Recombinant DNA is

the DNA resulting when genes of two different organisms are mixed.

Cells that are placed in a hypertonic environment (one in which the concentration of solute is greater that that of the cellular cytoplasm) will have which of the following effects?

the cell will dehydrate and die

Enzymes cease to work much above their optimal temperature because

the enzyme loses its structure and therefore its function

feedback inhibition (end-product inhibition)

the final product acts as a noncompetitive inhibitor of the first enzyme, which shuts down the pathway

active immunity means

the host cells are responsible for the immunity

Why might one have multiple drugs prescribed simultaneously for a single infection?

the likelihood of selecting for a resistant strain is less because a single cell would have to develop two types of resistance simultaneously

CHONPS is an acronym for

the macronutrients that all cells require

The emergence of new infectious diseases is probably due to all of the following except

the need of bacteria to cause disease.

Based on your understanding of the necessities for microbial growth. What is the mechanism that is preventing microbes from growing on a milky way?

the osmotic pressure in candy is too great for most microbe to be able to grow on it

An antimicrobial agent should meet all of the following criteria except

the production of hypersensitivities.

Spallanzani's conclusion about spontaneous generation was challenged because Lavoisier had just shown that oxygen was the vital component of air. Which of the following statements is true?

Some microbes do not require air.

Transducing particle causes a viral infection

Specialized

DNA

Stable storage molecule for genetic information

Cells are neither dividing nor dying or the number being produce equals the number being lost

Stationary

Studies biodegradation of toxic wastes

biotechnology and microbial ecology

Low pH discourages pathogen colonization. Which site on the body lacks this protection?

blood

Mutualism

both benefit

Natural selection is the differential survivability of individuals within a population. This is what drives evolution. In microbiology, natural selection is seen to act on

both microbial and host populations

unwinding proteins

breaks the hydrogen bonds holding the two DNA strands together

Gram stained bacterial cell

brightfield

A chemical that kills gram positive bacteria and gram negative bacteria is described as

broad spectrum

superoxide dismutase

converts superoxide to O2 and H2O2

DNA ligase

covalently joins contiguous DNA fragments

DNA ligase

covalently links adjacent nucleotides together

restriction enzymes

cuts double stranded DNA

Inhibits an enzyme by binding the allosteric site (any site other than the binding site)

non-competitive inhibitor

Which sterilizing technique specifically causes DNA damage?

non-ionizing radiation

Agar is for the most part

non-nutriative

Viruses

not a cell therefore does not have a cell wall

Viruses

not composed of cells

A virus with RNA-dependent RNA polymerase

synthesizes double-stranded RNA from an RNA template.

Which of the following is most effective for sterilizing mattresses and plastic Petri dishes?

ethylene oxide

One partner benefits, the other is unaffected

commensalism

Protozoa

lack cell walls

Metabolic Adjustment

lag

Microbes are removed or destroyed from living tissue

antisepsis

intracellular detail of an unstained eukaryote cell

phase contrast

Complete destruction or elimination of microbes

sterilization

Glycocalyx

-Attachment to surfaces -Protection from phagocytosis

Fermentation yields how much ATP net from a single glucose molecule?

2

rod shaped cell

bacillus

Fungi

cell wall made of chitin

motile (live) bacterial cell

darkfield

Which of the following pairs is mismatched?

pili—reproduction

Restriction enzymes have the following property

- Cut double stranded DNA -Leave protruding single strand DNA overhangs -Cut DNA at only particular prescribed DNA sequences

1. Rhinovirus is the virus most likely to cause the common cold. It has been known for some time that the transmission of this virus occurs by an uninfected person touching their nose then the hand of an uninfected person who then touches their own face. New research however, describes some transmission occurring by breathing in contaminated air in a room where a sneeze or a cough has occurred. This virus is most likely to be found in the respiratory tract of children and less often in adults and not in any other site. The mode of transmission for rhinovirus is

-Person to person direct contact -vehicle

Exotoxin

-protein -heat sensitive -usually potent effect on host

For a - RNA virus place the following steps in order for the biosynthesis stage of the viral cycle. synthesis of + RNA capsid synthesis synthesis of some - RNA synthesis of RNA dependent RNA polymerase

-synthesis of + RNA -synthesis of RNA dependent RNA polymerase -synthesis of - RNA capsid synthesis

1.For a + RNA virus place the following steps in order for the biosynthesis stage of the viral cycle. synthesis of + RNA capsid synthesis synthesis of some - RNA synthesis of RNA dependent RNA polymerase

-synthesis of RNA dependent RNA polymerase -synthesis of some - RNA -synthesis of + RNA, capsid synthesis

For a retro virus place the following steps in order for the biosynthesis stage of the viral cycle. synthesis of a first strand of DNA insertion of viral chromosome into cellular chromosome synthesis of +RNA synthesis of a second strand of DNA splitting of the long polypeptide into smaller protein molecules (including capsid proteins, integrase, reverse transcriptase and protease) synthesis of a single large polypeptide from the pro-virus

-synthesis of a first strand of DNA -synthesis of a second strand of DNA insertion of viral chromosome into cellular chromosome -synthesis of a single large mRNA encompassing the entire retroviral chromosome -synthesis of a single large polypeptide from the pro-virus -splitting of the long polypeptide into smaller protein molecules (including capsid proteins, integrase, reverse transcriptase, spike proteins and protease)

True Statements about viruses

-viruses do not divide-viruses do not have a cell membrane-viruses are small-mature viral particles have only one type of nucleic acid

Fermentation

2 ATP

Place the following in the most likely order for biosynthesis of a bacteriophage: (1) phage lysozyme; (2) mRNA; (3) DNA; (4) viral proteins; (5) DNA polymerase.

2,5,3,4,1,

Using a good compound light microscope with a resolving power of 0.3 μm, a 10× ocular lens, and a 100× oil immersion lens, would you be able to discern two objects separated by 3 μm? 0.3 μm? 300 nm?

2. resolution is the capacity to see as separate, two points that are close together. If resolution is 0.3 µm, then one can certainly resolve points that are separated by 3µm, ten times further away.0.3µm can be resolved.300 nm = 0.3µm so it also can be resolved. summary: yes, yes, yes.

The following is single strand from a double stranded DNA molecule. Use the choices to select which would be the second strand for this molecule.5' ATAT ATG AAA TTC GCG TGA 3'

3' TATA TAC TTT AAG CGC ACT 5'

Place the following in the order in which they are found in a host cell: (1) capsid proteins; (2) infective phage particles; (3) phage nucleic acid.

3,1,2

Order the appearance of viral nucleic acid from a retrovirus following uncoating from the following list. 1. DNA 2. DNA/RNA hybrid 3. single stranded RNA

3,2,1

Put the following in the correct order for virus replication:1. Maturation 2. Biosynthesis 3. attachment 4. penetration 5. release. 6. uncoating

3,4,6,2,1,5

Aerobic respiration

36-38 ATP

Complete aerobic oxidation of a single glucose molecule yields how much ATP net?

38

If E. coli can under ideal conditions divide every 20 minutes and if your blood is ideal (nice and warm, pH balanced, osmotically balanced, providing lots of macro and micro nutrients, uuuhhhmm), then how many bacteria would be in your blood one hour and 40 minutes after 12 microbes penetrated this organ system?

388

How many different naturally occurring DNA nucleotides are there?

4

Using the numerals, place the following into the correct order for a genetic engineering exercise. 1. transform bacteria with recombinant plasmid 2. treat plasmid DNA and 'target' DNA with the same restriction enzyme 3. treat plasmid DNA and 'target' DNA with DNA ligase 4. isolate plasmid DNA and 'target' DNA

4,2,3,1

Place the following steps of DNA replication in the correct order. 1. Contiguous DNA fragments are joined 2. Complimentary, anti-parallel DNA is made 3. a short complementary, anti-parallel RNA is made 4. DNA strands are separated

4,3,2,1

What total magnification is achieved when one is using 10x ocular lens and a 45x objective lens

450X

The following is single strand from a double stranded DNA molecule. What is the transcription product from this molecule3' ATAT TAC GGC CGA ATA ACT 5'

5' UAUA AUG CCG GCU UAU UGA 3'

Diffracted distorted light enhances small refractive differences in cells, useful for examining unstained eukaryote cells

Phase contrast

Based on the following information decide which flask is the correct answer. Flask A contains yeast cells in glucose-minimal salts broth incubated at 30 degrees centigrade. Flask B is identical except that it is being grown anaerobically. Which culture grew fastest?

A

Flask A contains yeast cells in glucose-minimal salts broth incubated at 30 degrees centigrade. Flask B is identical except that it is being grown anaerobically. Which culture produced more ATP?

A

Flask A contains yeast cells in glucose-minimal salts broth incubated at 30 degrees centigrade. Flask B is identical except that it is being grown anaerobically. Which culture produced more cells?

A

A-B toxins have two domains. What biological activity do the two domains have?

A active (interferes with some biological function of the cell) B binding

Using just one or two sentences describe why a catalyst allows a reaction to proceed at a lower temperature.

A catalyst 'hold's down reactants and allows them to get close enough together to react with bouncing away from each other. In the case of an enzyme it does this far more efficiently by 'holding' and orienting and 'squeezing' the substrates (reactants).

Which of the following would be the first step in the biosynthesis of a virus with reverse transcriptase?

A complementary strand of DNA must be synthesized from an RNA template.

What is the purpose of a counterstain in the acid-fast stain?

A counterstain stains the colorless non-acid-fast cells so that they are easily seen through a microscope.

unstained live tissue when it is desirable to see some intracellular detail

Phase-contrast microscope

Two types of prokaryotic cells have been distinguished: bacteria and archaea. How do these cells differ from each other? How are they similar?

A greater taxonomic grouping than kingdom is domain. Archaebacteria are so different than Eubacteria that they have been placed in a separate domain. To understand this, consider the following; humans and a rose bush are more similar to each other than archaebacteria and E. coli, are to each other. How they differ: cell wall, cell membrane, ribosome structure, gene architecture. How they are similar: the prokaryotes (archaebacteria and eubacteria) have no membrane enclosed organelles, and they both have (for the most part) a single circular chromosome whereas the eukaryotes have multiple linear chromosomes. The eukaryotes have many membrane enclosed organelles, e.g., nucleus, mitochondria, chloroplast, Golgi, endoplasmic reticulum and etc.

Which of the following statements is true?

A successful pathogen doesn't kill its host before it is transmitted.

List the four properties that define a virus. What is a virion?

A virus -contains DNA or RNA; -has a protein coat surrounding the nucleic acid; -multiplies inside a living cell using the synthetic machinery of the cell; and -causes the synthesis of virions. A virion is a fully developed virus particle that transfers the viral nucleic acid to another cell and initiates multiplication.

What are the base pairing rules for DNA?

A-T G-C

The maximum magnification of a compound microscope is (a)____ ; that of an electron microscope, (b) _______. The maximum resolution of a compound microscope is (c)________ ; that of an electron microscope, (d)_______ . One advantage of a scanning electron microscope over a transmission electron microscope is (e)________ .

A. 1500× B. 10,000,000× C. 0.2 μm D. 10 pm E. Seeing three-dimensional detail.

Some commonly used restriction enzymes are listed in Table 9.1. A. Indicate which enzymes produce sticky ends. B. Of what value are sticky ends in making rDNA?

A. BamHI, EcoRI, and HindIII make sticky ends. B. Fragments of DNA produced with the same restriction enzyme will spontaneously anneal to each other at their sticky ends.

Compare and contrast the following: A. simple diffusion and facilitated diffusion B. active transport and facilitated diffusion c. active transport and group translocation

A. Both allow materials to cross the plasma membrane from a high concentration to a low concentration without expending energy. Facilitated diffusion requires carrier proteins. B. Both require enzymes to move materials across the plasma membrane. In active transport, energy is expended. C. Both move materials across the plasma membrane with an expenditure of energy. In group translocation, the substrate is changed after it crosses the membrane.

Differentiate the terms in each of the following pairs: A. etiology and pathogenesis B. infection and disease C. communicable disease and noncommunicable disease

A. Etiology is the study of the cause of a disease, whereas pathogenesis is the manner in which the disease develops. B. Infection refers to the colonization of the body by a microorganism. Disease is any change from a state of health. A disease may, but does not always, result from infection. C. A communicable disease is a disease that is spread from one host to another, whereas a noncommunicable disease is not transmitted from one host to another.

A P next to Prokaryote and E next to Eukaryote A. Single circular chromosome _____ B. Multiple linear chromosomes _____ C. 80S ribosome _____ D. 70S ribosome _______ E. nucleus _______

A. P B. E C. E D. P E. E

Recall from Chapter 1 that Koch's postulates are used to determine the etiology of a disease. Why is it difficult to determine the etiology of A. a viral infection, such as influenza? B. cancer?

A. Viruses cannot easily be observed in host tissues. Viruses cannot easily be cultured in order to be inoculated into a new host. Additionally, viruses are specific for their hosts and cells, making it difficult to substitute a laboratory animal for the third step of Koch's postulates. B. Some viruses can infect cells without inducing cancer. Cancer may not develop until long after infection. Cancers do not seem to be contagious.

Explain how drugs that bind each of the following would affect pathogenicity: A. iron in the host's blood B. Neisseria gonorrhoeae fimbriae C. Streptococcus pyogenes M protein

A. Would inhibit bacteria. B. Would prevent adherence of N. gonorrhoeae. C. S. pyogenes would not be able to attach to host cells and would be more susceptible to phagocytosis.

Endospore formation is called (a)_______ . It is initiated by (b)_______ . Formation of a new cell from an endospore is called (c)________ . This process is triggered by (d)_______ .

A. sporogenesis B. certain adverse environmental conditions C. germination D. favorable growth conditions

The antimicrobial effect of gamma radiation is due to (a)______ . The antimicrobial effect of ultraviolet radiation is due to (b)_______ .

A. the ability of ionizing radiation to break DNA directly. However, because of the high water content of cells, free radicals (H · and OH ·) that break DNA strands are likely to form. B. formation of thymine dimers.

Which of the following are products of glycolysis?

ATP, pyruvic acid, NADH

active and passive immunity

Active immunity refers to antibodies produced by the individual who carries them. Passive immunity refers to antibodies produced by another source and then transferred to the individual who needs the antibodies.

ATP energy used to move a solute against the conc. gradient

Active transport

innate and adaptive immunity

Adaptive immunity is the resistance to infection obtained during the life of the individual; it results from the production of antibodies and T cells. Innate immunity refers to the resistance of species or individuals to certain diseases that is not dependent on antigen-specific immunity.

What are the four nitrogenous bases of DNA?

Adenine, Thymine, Cytosine, Guanine

. Six E. coli cells get into your blood stream. They have a generation time of 20 minutes. How many are there 20 minutes later? How many are there after two hours?

After 20 minutes: 12 After 2 hours: 384

What value does agar give to an agar plate?

Agar is a solidifying agent that allows one to spread a mix of different cells onto its surface to allow separate growth and later further characterization or identification

Define oxidation-reduction, and differentiate the following terms: respiration and fermentation

An electron transport chain is used in respiration but not in fermentation. The final electron acceptor in respiration is usually inorganic; in fermentation it is usually organic.

Why is an endospore called a resting structure? Of what advantage is an endospore to a bacterial cell?

An endospore is called a resting structure because it provides a method for one cell to "rest," or survive, as opposed to grow and reproduce. The protective endospore wall allows a bacterium to withstand adverse conditions in the environment.

Starch is readily metabolized by many cells, but a starch molecule is too large to cross the plasma membrane. How does a cell obtain the glucose molecules from a starch polymer? How does the cell transport these glucose molecules across the plasma membrane?

An extracellular enzyme (amylase) hydrolyzes starch into disaccharides (maltose) and monosaccharides (glucose). A carrier enzyme (maltase) hydrolyzes maltose and moves one glucose into the cell. Glucose can be transported by group translocation as glucose-6-phosphate.

1. The ecology class spends a lot of time in Tyler Park doing their thing. One of the students is bit by a tick that picked up some Borrelia from a mouse that the tick was feeding on. The Borrelia continued growing in the tick's stomach before it bit one of the students from the Eco class who then developed Lyme disease. The reservoir for Borrelia is

Animal

Into which group would you place a multicellular organism that has a mouth and lives inside the human liver?

Animalia

No cell wall, multicellular, ingest

Animalia

A basic dye

Answer: All of the above -is positively charged -easily adheres to most cells that have not been manipulated -includes both dyes in the gram stain -has a color associated with it

The ability of a virus to infect an organism is regulated by

Answer: All of the above -the host species. -the type of cells. -the availability of an attachment site. -cell factors necessary for viral replication.

Meningitis can be caused by

Answer: All of the above viruses, bacteria, fungi, protozoa

Which of the following is a beneficial activity of microorganisms?

Answer: All of the above -Some microorganisms are used as food for humans. -Some microorganisms use carbon dioxide. -Some microorganisms provide nitrogen for plant growth. -Some microorganisms are used in sewage treatment processes.

Dideoxyinosine (ddI) is an antimetabolite of guanine. The -OH is missing from carbon 3' in ddI. How does ddI inhibit DNA synthesis?

DNA polymerase adds bases to the 3'-OH.

which of the following is something that antibodies can't do?

Answer: Build a snowman. Kind of a dumb answer but here I listed the things they can do incase he asks the opposite -attach to viruses and prevent the first part of their life cycle (attachment) -attach to toxins or any microbe and prevent them from adhering to target tissue -act as opsonin-agglutinate foreign material to enhance phagocytosis -active complement

How do normal flora protect us?

Answer: all of the above - they produce acid that discourages growth of pathogens - they kill other microbes including pathogens with poisonous compounds - they prevent pathogens from adhering -diminish available nutrients making it difficult for pathogens to survive

Which kingdoms include eukaryote cells?

Answer: all of the above -Animalia -Plantae -Fungi -Protista

Superantigens are toxins that unlike normal antigens that would stimulate 0.0001-0.001% of T cells can stimulate up to 100% of T cells to release cytokines, small proteins that elicit a number of biological effects. One possible outcome from a superantigen exposure would be toxic shock. The toxic shock would be responsible for

Answer: all of the above a. Vasodilation b. Increased blood vessel permeability c. Lowered blood pressure d. Failure to adequately perfuse the organs with sufficient volumes of blood e. Death

Genetic engineering is the artificial introduction of a gene from one organism into another. Into which organisms has this been successfully accomplished?

Answer: all of the above Bacteria, Yeast, Plants, Animals, Humans

A drug that inhibits peptidoglycan synthesis is

Antibacterial

Clostridia difficile typically causes a diarrheal disease predominantly in hospital settings in patients who have had long term antibiotic therapy. Why?

Antibiotic therapy eliminates the protective normal flora allowing the patients to be more susceptible to this infection.

Who is credited with the discovery of microbes?

Anton van Leuwenhoek

Prokaryotes, cell wall not peptidoglycan,

Archaea

The chemoautotroph Acidithiobacillus can obtain energy from the oxidation of arsenic (As3+ → As5+). How does this reaction provide energy? How can humans put this bacterium to use?

Arsenic loses two electrons from its' outer energy shells (these are high energy electrons) they are passed down and electron transport chain whereby the energy in the electrons is used to make ATP via chemiosmosis (this is obviously a chemoautotroph). The more highly ionized form of a toxic metal is less likely to cross a biological membrane and therefore is less toxic than the less ionized form.

Place the steps in the viral life cycle in order: Biosynthesis Assembly Uncoating Attachment Penetration release

Attachment penetration (entry) uncoating biosynthesis assembly (maturation) release

Fimbrae

Attachment to surfaces

The thermal death time for a suspension of Bacillus subtilis endospores is 30 minutes in dry heat and less than 10 minutes in an autoclave. Which type of heat is more effective? Why?

Autoclave. Because of the high specific heat of water, moist heat is readily transferred to cells.

Only refracted light from specimen reaches objective lens, unstained specimens are easily visualized

Dark field

The number of cells is decreasing logarithmically

Death

Normal flora protect against pathogens in all of the following ways except

produces antibodies

Flask A contains yeast cells in glucose-minimal salts broth incubated at 30 degrees centigrade. Flask B is identical except that it is being grown anaerobically. Which culture produced more alcohol?

B

Single cells, cell wall peptidoglycan

Bacteria

What type of microorganism has a peptidoglycan cell wall, has DNA that is not contained in a nucleus, and has flagella?

Bacterium

A mutagen that alters adenine so that it base-pairs with cytosine

Base-pair mutagen

What similar problems are encountered with antiviral, antifungal, antiprotozoan, and antihelminthic drugs?

Because a virus uses the host cell's metabolic machinery, it is difficult to damage the virus without damaging the host. Fungi, protozoa, and helminths possess eukaryotic cells. Therefore, antiviral, antifungal, antiprotozoan, and antihelminthic drugs must also affect eukaryotic cells.

biofilms

Biofilms are aggregated bacteria adhering to each other and to a solid surface.

Studies the production of human proteins by bacteria

Biotechnology Microbial genetics Microbial Physiology

Which of the following is not a portal of entry for pathogens?

Blood

Which culture uses NAD+?

Both A and B

Compare biosynthesis of a + stranded RNA and a − stranded RNA virus.

Both produce double-stranded RNA, with the - strand being the template for more + strands. + strands act as mRNA in both virus groups.

Find at least three supermarket products made by microorganisms. (Hint: The label will state the scientific name of the organism or include the word culture, fermented, or brewed.)

Bread, yogurt, pickles, olives, wine, beer (some states), sauerkraut, chocolate, vanilla, Tabasco, soy sauce, miso, sausages and others.

Utilitarian, difficult to use high magnification without staining specimen

Bright field

CD8+ T cell and CTL

CTLp cells cannot kill other cells until they are activated to CTLs by an antigen-presenting cell.

Suppose you inoculate three flasks of minimal salts broth with E. coli. Flask A contains glucose. Flask B contains glucose and lactose. Flask C contains lactose. After a few hours of incubation, you test the flasks for the presence of β-galactosidase. Which flask(s) do you predict will have this enzyme?

C

Which of the following compounds has the greatest amount of energy for a cell?

CO2

Explain a function for the following types of cells: CTL, TH, and Treg. What is a cytokine?

CTLs destroy target cells on contact. TH cells interact with an antigen to "present" it to a B cell for antibody formation. TR cells suppress the immune response. Cytokines are chemicals released by cells that initiate a response by other cells.

yeast infection in women, infection in the oral cavity

Candida albicans

Recycling of Elements

Carbon, oxygen, nitrogen, sulfur and phosphorus are required for all living organisms. Microorganisms convert these elements into forms that are useful for other organisms.

Macronutrients (needed in relatively large amounts) are often listed as CHONPS. What does each of these letters indicate, and why are they needed by the cell?

Carbon: synthesis of molecules that make up a living cell. Hydrogen: source of electrons and component of organic molecules. Oxygen: component of organic molecules; electron acceptor in aerobes. Nitrogen: component of amino acids. Phosphorus: in phospholipids and nucleic acids. Sulfur: In some amino acids.

Mechanism by which the presence of glucose inhibits the lac operon.

Catabolite Repression

Catalase

Catalyzes the breakdown of H2O2 to O2 and H2O.

peroxidase

Catalyzes the breakdown of H2O2;

Rigid structure allows resistance to osmotic lysis

Cell wall

Algae

Cell wall made of cellulose

Algae

Cell wall made of cellulose; photosynthetic

Biological control of pests

Certain microorganisms cause diseases in insects. Microorganisms that kill insects can be effective biological control agents because they are specific for the pest and do not persist in the environment.

Distinguish symptoms from signs as signals of disease.

Changes in body function that the patient feels are called symptoms. Symptoms such as weakness or pain are not measurable by a physician. Objective changes that the physician can observe and measure are called signs.

Mutations occur when there is an error in DNA replication. These errors can happen spontaneously during normal DNA synthesis but they can also occur whenever the cell is repairing DNA damage. The more damage, the more repair, the most likely you will have an alteration in your DNA. One sad outcome of DNA mutation is the alteration of a gene responsible for maintaining normal cell division. Alterations in these genes can lead to cancer. There is an epidemic of skin cancer in young people in the US, thought to be related to the increasing amount of exposure to the DNA damaging UV radiation from tanning parlors. What precisely is the nature of the DNA damage when UV is the initiating agent?

Chemical fusion of adjacent thymines in a single strand

Live cultures of Bacillus thuringiensis (Dipel®) and B. subtilis (Kodiak®) are sold as pesticides. What bacterial structures make it possible to package and sell these bacteria? For what purpose is each product used?

Clostridia are soil bacteria and spore forming. The spores have unusually good shelf life with out refrigeration (possibly millions of years in extreme temp. and dryness). Bacillus thuringenesis is used as an insecticide, a product homeowners can put in their ponds to control for mosquitoes. It is also sprayed on crops as an insecticide and its toxin gene has been engineered into a number of different agriculturally important plants to control for insects. Bacillus subtilis produces a fungicide. Another spore former is Bacillus anthracis, a great choice for a bio weapon for the same reasons as above.

Clostridium and Streptococcus are both catalase-negative. Streptococcus grows by fermentation. Why is Clostridium killed by oxygen, whereas Streptococcus is not?

Clostridium is an obligate anaerobe (lacks SOD and catalase and peroxidase) in an oxygen environment it will produce oxygen free radicals and kill itself. Streptococcus on the other hand has SOD and peroxidase (catalase unnecessary if one has peroxidase) and survives the oxygen atmosphere. (In truth, because Clostridia are all spore formers, the spore form of these cells would survive the oxygen environment).

You are provided with cultures with the following characteristics: Culture 1: F+, genotype A+ B+ C+ Culture 2: F-, genotype A-B Indicate the possible genotypes of a recombinant cell resulting from the conjugation of cultures 1 and 2. Indicate the possible genotypes of a recombinant cell resulting from conjugation of the two cultures after the F+ has become an Hfr cell.

Culture 1 will remain the same. Culture 2 will convert to F+ but will have its original genotype. The donor and recipient cells' DNA can recombine to form combinations of A+B+C+ and A-B-C-. If the F plasmid also is transferred, the recipient cell may become F +.

Briefly describe the components of DNA, and explain its functional relationship to RNA and protein.

DNA consists of a strand of alternating sugars (deoxyribose) and phosphate groups with a nitrogenous base attached to each sugar. The bases are adenine, thymine, cytosine, and guanine. DNA exists in a cell as two strands twisted together to form a double helix. The two strands are held together by hydrogen bonds between their nitrogenous bases. The bases are paired in a specific, complementary way: A-T and C-G. The information held in the sequence of nucleotides in DNA is the basis for synthesis of RNA and proteins in a cell.

UV is sterilizing because

DNA damage is done beyond what can be repaired

Covalently attaches adjacent DNA fragments

DNA ligase

Mixing DNAs together from different sources both cut with the same restriction enzyme can hydrogen base pair together. What enzyme can assure that the DNAs stay locked together?

DNA ligase

Which of the following is an enzyme in normal DNA replication and is used often in gene cloning?

DNA ligase

Synthesizes complementary, anti-parallel DNA

DNA polymerase

Blood agar is a very rich medium that allows the growth of many bacteria that would not grow on TSA. Furthermore, the bacteria that causes strep throat can be tentatively suspected from growth on this media by a clear zone they produce around their colonies. This medium can be best describe as

Differential

Blood agar plates are particularly valuable in identifying Streptococci. In particular alpha, beta, and gamma hemolytic colonies are distinguished. Blood agar plates in this context can be described as

Differential

Define drug resistance. How is it produced? What measures can be taken to minimize drug resistance?

Drug resistance is the lack of susceptibility of a microorganism to a chemotherapeutic agent. Drug resistance may develop when microorganisms are constantly exposed to an antimicrobial agent. Ways to minimize the development of drug-resistant microorganisms include judicious use of antimicrobial agents; following directions on the prescription; or administering two or more drugs simultaneously.

How can a local infection become a systemic infection?

When microorganisms causing a local infection enter a blood or lymph vessel and are spread throughout the body, a systemic infection can result.

Which culture uses the most glucose?

E. coli growing in glucose broth at 35C without O2 for 5 days

Which culture produces the most ATP?

E. coli growing in glucose broth at 35°C with O2 for 5 days

Which culture produces the most lactic acid?

E. coli growing in glucose broth at 35°C without O2 for 5 days

Which of the following statements is false?

E. coli never causes disease.

Which of the following statements about E. coli is false?

E. coli was the first disease-causing bacterium identified by Koch.

Developed the first vaccine

Edward Jenner

Inventor of vaccinations?

Edward Jenner

intracellular detail of a cell that is 1 μm long

Electron microscope

How are capsules and cell wall components related to pathogenicity? Give specific examples.

Encapsulated bacteria can resist phagocytosis and continue growing. Streptococcus pneumoniae and Klebsiella pneumoniae produce capsules that are related to their virulence. M protein found in the cell walls of Streptococcus pyogenes and mycolic acid in the cell walls of Mycobacterium help these bacteria resist phagocytosis.

Inert, highly resistant form of a bacterial cell

Endospore

How can the complement system cause endotoxic shock?

Endotoxin binds C3b, which activates C5-C9 to cause cell lysis. This can result in free cell wall fragments, which bind more C3b, resulting in C5-C9 damage to host-cell membranes.

What kingdoms contain the prokaryotes?

Eubacteria (bacteria) and Archaebacteria (archaea)

Which type of cell contains a nucleus?

Eukaryotes

Parts of a compound light microscope

Eyepiece, Arm, Coarse focus knob, Fine focus knob, Objective lenses, Revolving nosepiece, Stage, Light source, Base.

Which of the following requires a sex pilus?

F+ mating Hfr mating

. An F+ cell able to ferment the sugars lac, suc and glu (F+, lac+, suc+, glu+)because of chromosomal genes mates with an F- cell that is unable to ferment any of these sugars (F-, lac-, suc-,glu-). After the mating what would be the most likely genotype of the two cells?

F+, lac+, suc+, glu+ F+, lac-, suc-,glu-

Solute moves from high conc. to low conc. via a transport protein

Facilitated diffusion

spontaneous generation

False

Small hair like projection used for attachment

Fimbriae

Long filament used for motility

Flagella

a sample that emits light when illuminated with ultraviolet light

Fluorescence microscope

UV light is lengthened to visible light

Fluorescent

Who disproved spontaneous generation for maggots?

Francesco Redi

Single cell or multicellular, cell wall chitin

Fungi

Transducing particle cannot cause a viral infection

Generalized

Which of the following is a portal of exit?

Genital Tract

Sometimes called beaver fever but really the reservoir are wild mammals that spread the diarrhea causing pathogen into the water

Giardia lamblia

Which type of cell has a thick peptidoglycan (no mycolic acid)?

Gram +

Which type of cell has an additional phospholipid bilayer exterior to the peptidoglycan?

Gram -

Which type of cell has lipopolysaccharide as part of its cell wall?

Gram -

Solute moves from high conc. to low conc. and the transport protein chemically modifies the solute

Group translocation

hydrogen peroxide

H2O2; peroxide ion is O22-.

In 1985, a 0.5-mm cell was discovered in surgeonfish and named Epulopiscium fishelsoni (see Figure 11.20, page 313). It was presumed to be a protozoan. In 1993, researchers determined that Epulopiscium is actually a gram-positive bacterium. Why do you suppose this organism was initially identified as a protozoan? What evidence would change the classification to bacterium?

Initially identified as a protozoan because of its' unusual size (much larger than a typical eukaryote!). Eventually identified as a bacterium presumably because of peptidoglycan cell wall, 70S ribosome, no nucleus (or any membrane enclosed organelles).

Describe how hemolysins, leukocidins, coagulase, kinases, hyaluronidase, siderophores, and IgA proteases might contribute to pathogenicity.

Hemolysins lyse red blood cells; hemolysis might supply nutrients for bacterial growth. Leukocidins destroy neutrophils and macrophages that are active in phagocytosis; this decreases host resistance to infection. Coagulase causes fibrinogen in blood to clot; the clot may protect the bacterium from phagocytosis and other host defenses. Bacterial kinases break down fibrin; kinases can destroy a clot that was made to isolate the bacteria, thus allowing the bacteria to spread. Hyaluronidase hydrolyzes the hyaluronic acid that binds cells together; this could allow the bacteria to spread through tissues. Siderophores take iron from host iron-transport proteins, thus allowing bacteria to get iron for growth. IgA proteases destroy IgA antibodies; IgA antibodies protect mucosal surfaces.

If the F+ cell converted to an Hfr and then mated with the F- cell what would be the genotype of the two cells after mating?

Hfr+, lac+, suc+, glu+ F-, lac+, suc+,glu+

Among hospital patients who have infections, one-third did not enter the hospital with the infection but rather acquired it in the hospital. How do they acquire these infections? What is the method of transmission of these infections? What is the reservoir of infection?

Hospital patients may be in a weakened condition and therefore predisposed to infection. Pathogenic microorganisms are generally transmitted to patients by contact and airborne transmission. The reservoirs of infection are the hospital staff, visitors, and other patients.

1. Rhinovirus is the virus most likely to cause the common cold. It has been known for some time that the transmission of this virus occurs by an uninfected person touching their nose then the hand of an uninfected person who then touches their own face. New research however, describes some transmission occurring by breathing in contaminated air in a room where a sneeze or a cough has occurred. This virus is most likely to be found in the respiratory tract of children and less often in adults and not in any other site. The reservoir for this cold virus is

Human

Vibrio cholera causes a potent diarrheal disease in humans. It is not known to grow anywhere else. The bacteria can accumulate in shellfish that has been contaminated with human waste. Many people can get sick from eating raw or undercooked shellfish. The reservoir for cholera is

Human

referring to the question about Indirect contact, the reservoir is?

Humans

humoral and cellular immunity

Humoral immunity is due to antibodies (and B cells). Cellular immunity is due to T cells.

When E. coli cells are exposed to a hypertonic solution, the bacteria produce a transporter protein that can move K+ (potassium ions) into the cell. Of what value is the active transport of K+, which requires ATP?

If a cell is placed in a hypertonic environment (see fig. 4.18 e) it will dehydrate and die like a dog. By actively transporting K+ into the cell the E. coli raises its' internal solute concentration to greater than the environment it is in thus 'changing' the hypertonic environment to a hypotonic environment. Diffusion of water (osmosis) is reversed and the cell stays fully hydrated. Stay ahead of your thirst!

dimer, major antibody of secretions, major antibody of milk

IgA

found on the surface of B cells

IgD

Antibodies that are bound to mast cells and involved in allergic reactions.

IgE

bound to mast cells, mediator of allergic response

IgE

major antibody of the blood, fixes complement

IgG

Antibodies that protect the fetus and newborn.

IgG Multiple choice question 5 is a little dicey. IgG is certainly correct for fetus and newborn (IgG that is present in fetus at time of birth will persist for months) but IgA is certainly also a correct answer for a newborn that is being breast feed.

The first antibodies synthesized; especially effective against microorganisms.

IgM

pentamer, first antibody to be produced after exposure to antigen

IgM

immunoglobulin and TCR

Immunoglobins = antibodies; TCRs = antigen receptors on T cells.

Why is a mordant used in the Gram stain? In the flagella stain?

In a Gram stain, the mordant combines with the basic dye to form a complex that will not wash out of gram-positive cells. In a flagella stain, the mordant accumulates on the flagella so that they can be seen with a light microscope

Describe binary fission.

In binary fission, the cell elongates, and the chromosome replicates. Next, the nuclear material is evenly divided. The plasma membrane invaginates toward the center of the cell. The cell wall thickens and grows inward between the membrane invaginations; two new cells results.

What is the purpose of a decolorizer in the Gram stain? In the acid-fast stain?

In the Gram stain, the decolorizer removes the color from gram-negative cells. In the acid-fast stain, the decolorizer removes the color from non-acid-fast cells.

Norovirus cases are usually down to ill people vomiting in public places, having diarrhea in the public lavatories and handling all the railings and elevator buttons with unwashed hands. What is the method of transmission?

Indirect contact

The mechanism by which lactose controls the lac operon.

Induction

Define inflammation, and list its characteristics.

Inflammation is the body's response to tissue damage. The characteristic symptoms of inflammation are pain, redness, immobility, swelling, and heat.

Give several examples of how microbes evade the complement system.

Inhibit formation of C3b; prevent MAC formation; hydrolyze C5a.

What are interferons? Discuss their roles in innate immunity.

Interferons are defensive proteins. Alpha interferon and beta interferon induce uninfected cells to produce antiviral proteins. Gamma interferon is produced by lymphocytes and activates neutrophils to kill bacteria.

Which of the following statements best describes what happens to a cell exposed to polymyxins that destroy phospholipids?

Intracellular contents will leak from the cell.

What are the halogens and how are they used as anti microbials?

Iodine (and iodinated compounds) mostly as antiseptics but for some campers is used to disinfect drinking water Chlorine (and chlorinated compounds) mostly used as a disinfectant for drinking water and swimming pools, household cleaner Bromine swimming pools, hot tubs Fluorine (fluoridated compounds) strengthens bone making it more resistant to microbial destruction, but also anti microbial

A mutagen that causes the formation of highly reactive ions

Ionizing radiation

One way that hosts restrict growth of pathogens is to make certain essential micronutrients are unavailable to the microbe. Transferrin and lactoferrin bind almost all of the essential ____________ .

Iron

Developed antisepsis

Joseph Lister

Who first developed antiseptics?

Joseph Lister

Cells are metabolically adjusting to their environment, the number of cells is unchanged

Lag

Fever can be cause by a number of different insults, not the least of which is microbial infection. Besides the direct host benefits (p. 463) there may be some indirect benefit from interruption of microbial growth. Alteration of temperature is most likely to move the microbe from log to which other growth phase?

Lag

Which of the following statements is the best definition of biogenesis?

Living cells can only arise from preexisting cells.

The number of cells is increasing logarithmically

Log

Disproved spontaneous generation

Louis Pasteur

Who effectively ended the debate about spontaneous generation by showing microbes cannot grow in a swan necked flask that had been heat treated yet still exposed to air?

Louis Pasteur

A patient with streptococcal sore throat takes penicillin for 2 days of a prescribed 10-day regimen. Because he feels better, he then saves the remaining penicillin for some other time. After 3 more days, he suffers a relapse of the sore throat. Discuss the probable cause of the relapse.

Many bacteria were killed initially, so the patient started to feel better. Recall that bacterial die logarithmically, so it takes quite a while to kill an entire population. As penicillin concentration in the body drops the microbes remaining start growing again. Of course, now, the ones that are still alive are potentially more resistant.

Use the codon table in your text book to answer this question. Translate the following mRNA 5'UAUA AUG CCG GCU UAU UGA3'

Met-Pro-Ala-Tyr

Studies biodegradation of pollutions

Microbial Ecology

Studies the production of toxin by E. coli

Microbial physiology

Vaccine production

Microorganisms can be used as vaccines. Some microbes can be genetically modified to produce components of vaccines.

Assume that you are viewing a Gram-stained sample of vaginal discharge. Large (10 μm) nucleated red cells are coated with small (0.5 μm wide by 1.5 μm long) blue cells on their surfaces. What is the most likely explanation for the red and blue cells?

Most large (10 µm diameter and larger) cells that have a nucleus are eukaryotes. 10 µm is a bit on the small size. These cells may be yeast, the cause of a very common infection in women. The smaller cells (about the size of average bacteria, see figure 3.2) are probably Gram + bacilli, a common normal flora of that physiological region.

Flagella

Motility

In the 1960s, many physicians and the public believed that infectious diseases were retreating and would be fully conquered. Discuss why this didn't happen. Is it possible?

Multiple drug resistant Mycobacterium tuberculosis, Helicobacter pyloris (stomach ulcers), West Nile Virus, Influenza and many, many more. We are creating some new threats by poor use of antibiotics, we are discovering new ones that were probably always there. Disruption of the environment, moving closer to other environments (Lyme disease), population disruptions, wars, famines, weather and other natural disasters all play a role in causing an emerging or re-emerging infectious disease.

Why are mutation and recombination important in the process of natural selection and the evolution of organisms?

Mutation and recombination provide genetic diversity. Environmental factors select for the survival of organisms through natural selection. Genetic diversity is necessary for the survival of some organisms through the processes of natural selection. Organisms that survive may undergo further genetic change, resulting in the evolution of the species.

Why are mutation and recombination important for the survivability of a population?

Mutation and recombination tend to increase the variability in a population. Diversity of characteristics in individuals in a population helps insure that some individuals in the population will have the sufficient necessary characteristics for survival.

Why are some organisms that constitute the normal microbiota described as commensals, whereas others are described as mutualistic?

Mutualistic microorganisms are providing a chemical or environment that is essential for the host. Commensal organisms are not essential; another microorganism might serve the function as well.

Which of the following is a scientific name?

Mycobacterium tuberculosis

Why must NADH be reoxidized? How does this happen in an organism that uses respiration? Fermentation?

NAD+ is needed to pick up more electrons. NADH is usually reoxidized in respiration. NADH can be reoxidized in fermentation.

The electron carriers accept electrons in their Oxidized forms. Which are

NAD+, FAD

natural and artificial immunity

Natural immunity is acquired naturally, i.e., from mother to newborn or following an infection. Artificial immunity is acquired from medical treatment, i.e., by injection of antibodies or by vaccination.

A mutagen that causes the formation of pyrimidine dimers

Nonionizing radiation

normal microbiota

Normal microbiota are microorganisms that are found in and on the human body. They do not usually cause disease and can be beneficial.

A mutagen that is incorporated into DNA in place of a normal base

Nucleoside analog

superoxide radical

O2-; this anion has one unpaired electron.

How did the theory of biogenesis lead the way for the germ theory of disease?

Once it was understood that microbes arise from other microbes it was an easy step to realize that microbes growing on organic material could putrefy the organic material and likewise could grow on humans and cause disease.

Sewage treatment

Organic matter in sewage is decomposed by bacteria into carbon dioxide, nitrates, phosphates, sulfate and other inorganic compounds in a wastewater treatment plant

During catabolism the organic substrates are

Oxidized

The electron carriers accept electrons in their

Oxidized form

Biotechnology offers a powerful technique to identify small amounts of pathogens in our food supply. This is done by using

PCR

One method to make many more copies of DNA from a small region of chromosome of known DNA sequence is

PCR

Which of the following does not kill endospores?

Pasteurization

If pasteurization does not achieve sterilization, why is pasteurization used to treat food?

Pasteurization destroys most organisms that cause disease or rapid spoilage of food.

the first antibiotic discovered by Alexander Fleming was called

Penicillin

How did the idea of spontaneous generation come about?

People came to believe that living organisms arise from nonliving matter because they would see flies coming out of manure, maggots coming out of dead animals, and microorganisms appearing in liquids after a day or two.

Nitrogen and phosphorus added to beaches following an oil spill encourage the growth of natural oil-degrading bacteria. Explain why the bacteria do not grow if nitrogen and phosphorus are not added.

Petroleum can meet the carbon and energy requirements for an oil-degrading bacterium; however, nitrogen and phosphate are usually not available in large quantities. Nitrogen and phosphate are essential for making proteins, phospholipids, nucleic acids, and ATP.

One non-specific mechanism of protection is washing microbes off of the body. Which of the following is not an instrument of washing microbes off of the body?

Phagocytic cells

Identify at least one physical factor and one chemical factor that prevent microbes from entering the body through each of the following: A. urinary tract b. reproductive tract

Physical: movement out; Chemical: lysozome; acids Physical: movement out; Chemical: acidic environment in female

Long filament used for transferring DNA

Pilus

Photosynthetic, multicellular, true tissues

Plants

malaria

Plasmodium, several species

Synthesizes a small RNA

Primase

Archaea

Prokaryote without peptidoglycan cell wall

Cell wall

Protection from osmotic lysis

Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan wall surrounded by an outer membrane?

Proteobacteria (gram-negative bacteria)

Includes, algae, protozoa

Protista

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.

Quaternary ammonium compounds are most effective against gram-positive bacteria. Gram-negative bacteria that were stuck in cracks or around the drain of the tub would not have been washed away when the tub was cleaned. These gram-negative bacteria could survive the washing procedure. Some pseudomonads can grow on quats that have accumulated.

human insulin production

Recombinant DNA techniques have resulted in insertion of the gene for insulin production into bacteria. These bacteria can produce human insulin inexpensively.

Laboratory diagnosis of Neisseria gonorrhoeae infection is based on microscopic examination of Gram-stained pus. Locate the bacteria in this light micrograph . What is the disease?

Referring to figure 3.2 you can see that most eukaryote cells are larger than 10 µm and most bacterial cells are smaller than 10 µm. Furthermore, pus is mostly made up of phagocytic white blood cells. The large cells with a nucleus are WBC, the very small red colored spherical shapes are Gram - diplococci, in this case the Neisseria gonorrhoeae.The disease caused by this microbe is gonorrhea.

Which of the following is a portal of entry

Respiratory tract

Endospore

Resting

Organelle responsible for protein synthesis

Ribosome

Cell

Ribosomes has a membrane divides metabolsim

First person, using a compound light microscope, describes the cell.

Robert Hooke

Invented the microscope

Robert Hooke

Demonstrated the causative role of microbes in disease

Robert Koch

How do salts and sugars preserve foods? Why are these considered physical rather than chemical methods of microbial control? Name one food that is preserved with sugar and one preserved with salt. How do you account for the occasional growth of Penicillium mold in jelly, which is 50% sucrose?

Salts and sugars create a hypertonic environment. Salts and sugars (as preservatives) do not directly affect cell structures or metabolism; instead, they alter the osmotic pressure. Jams and jellies are preserved with sugar; meats are usually preserved with salt. Molds are more capable of growth in high osmotic pressure than are bacteria.

Electrons are reflected off of a specimen, 3-D appearing

Scanning electron

In 1864, Lister observed that patients recovered completely from simple fractures but that compound fractures had "disastrous consequences." He knew that the application of phenol (carbolic acid) to fields in the town of Carlisle prevented cattle disease. Lister treated compound fractures with phenol, and his patients recovered without complications. How was Lister influenced by Pasteur's work? Why was Koch's work still needed?

Similar answer to Crit. Think. 1. Pasteur showed that microbes were spoiling the wine. Destroying the microbes prevented certain consequences. Speculation led to rigorous testing (with controls) and corroboration, the hallmarks of the scientific method.

Solute moves from high conc. to low conc. unassisted across the phospholipid bilayer

Simple diffusion

List the advantages of using two chemotherapeutic agents simultaneously to treat a disease. What problem can occur when two drugs are used?

Simultaneous use of two agents can prevent the development of resistant strains of microorganisms, take advantage of the synergistic effect, provide therapy until a diagnosis is made, and lessen the toxicity of individual drugs by reducing the dosage of each in combination. One problem that can result from simultaneous use of two agents is an antagonistic effect.

Explain why, even under ideal conditions, Streptococcus grows slowly.

Streptococcus while aerotolerant grows only by fermentation. Because it is only capturing 2 ATP per glucose molecule compared to 38 ATP for aerobic respiring bacteria it is about twenty times less efficient at growth.

Define symbiosis. Differentiate commensalism, mutualism, and parasitism, and give an example of each.

Symbiosis refers to unlike organisms living together. Commensalism—one of the organisms benefits and the other is unaffected; e.g., corynebacteria living on the surface of the eye. Mutualism—both organisms benefit; e.g., E. coli receives nutrients and a constant temperature in the large intestine and produces vitamin K and certain B vitamins that are useful for the human host. Parasitism—one organism benefits while the other is harmed; e.g., Salmonella enterica receives nutrients and warmth in the large intestine, and the human host experiences gastroenteritis or typhoid fever.

RNA polymerase

Synthesizes a short complimentary, anti-parallel primer RNA

Which of the following is not a general category for reservoir?

T cells

T-dependent and T-independent antigens

T-dependent antigens: Certain antigens must combine with self-antigens to be recognized by TH cells and then by B cells. T-independent antigens can elicit an antibody response without T cells.

intracellular detail of a bacterial cell

TEM microscope

TH1 and TH2 cells

TH1 cells produce cytokines that activate T cells. Cytokines produced by TH2 cells activate B cells.

An opportunistic pathogen is one that

Takes advantage of the compromised host

Compare pathogenicity with virulence.

The ability of a microorganism to produce a disease is called pathogenicity. The degree of pathogenicity is virulence.

Which statement best describes what happens when a gram-positive bacterium is placed in distilled water and penicillin?

The cell will undergo osmotic lysis.

Which of the following is not one of Koch's postulates?

The disease must be transmitted from a diseased animal to a healthy, susceptible animal by direct contact.

List and explain five criteria used to identify an effective antimicrobial agent.

The drug (1) should exhibit selective toxicity; (2) should have a broad spectrum; (3) should not produce hypersensitivity in the host; (4) should not produce drug resistance; and (5) should not harm normal microbiota.

substrate-level phosphorylation

The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.

Define oxidation-reduction, and differentiate the following terms: aerobic and anaerobic respiration

The final electron acceptor in aerobic respiration is molecular oxygen; in anaerobic respiration, it is another inorganic molecule.

Suppose you want multiple copies of a gene you have synthesized. How would you obtain the necessary copies by cloning? By PCR?

The gene can be spliced into a plasmid and inserted into a bacterial cell. As the cell grows, the number of plasmids will increase. The polymerase chain reaction can make copies of a gene using DNA polymerase and a primer for the gene.

Even though the germ theory of disease was not demonstrated until 1876, why did Semmelweis (1840) and Lister (1867) argue for the use of aseptic techniques?

The germ theory of disease was unequivocally demonstrated by Robert Koch in 1876 but before that determining event there was a tremendous amount of data that was supporting the hypothesis.

By deep-freezing, bacteria can be stored without harm for extended periods. Why do refrigeration and freezing preserve foods?

The growth rate of bacteria slows down with decreasing temperatures. Mesophilic bacteria will grow slowly at refrigeration temperatures and will remain dormant in a freezer. Bacteria will not spoil food quickly in a refrigerator.

What does MHC stand for? What is the function of MHC? What types of T cells interact with MHC class I? With MHC class II?

The major histocompatability complex (MHC) are self-antigens. CTL cells react with MHC I; TH cells react with MHC II.

Different species of Clostridia can cause disease in humans. These bacteria are obligate anaerobes. How can they cause disease in humans?

The microbes are spore formers and can survive until they find an anaerobic environment, at which time they can germinate into vegetative cells. The intestinal tract, necrotic tissue, and adipose tissue all offer sequestered areas of sufficiently low oxygen concentration for these microbes to thrive

Which of the following statements is false?

The nucleic acid of a virus is surrounded by a protein coat.

Photophosphorylation

The process of generating ATP from ADP and phosphate by means of a proton-motive force generated by the thylakoid membrane of the chloroplast during the light reactions of photosynthesis.

oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.

A hematologist often performs a differential white blood cell count on a blood sample. Why are these numbers important? What do you think a hematologist would find in a differential white blood cell count of a patient with mononucleosis? With neutropenia? With eosinophilia?

The proportion of white blood cells may change during disease. The results of a differential count can be used to diagnose diseases. A patient with mononucleosis (commonly caused by an infection with the Epstein-Barr virus) will have an increased number of monocytes. Neutropenia: decreased neutrophils (many causes including virus diseases, tuberculosis, typhoid).Eosinophilia: increased eosinopohils (often associated with helminth infection if not due to asthma or hay fever).

Why does hemolysis of red blood cells occur when a person receives a transfusion of the wrong type of blood?

The recipient's antibodies combine with donor antigens and fix complement; the activated complement causes hemolysis.

The specificity of an antibody is due to

The variable portions of the H and L chains

Why did the use of DNA polymerase from the bacterium Thermus aquaticus allow researchers to add the necessary reagents to tubes in a preprogrammed heating block?

Thermus aquaticus (hot water). The bacterium was first discovered in the Great Fountain region of Yellowstone National Park and has since been found in similar thermal habitats around the world. The enzymes in these bacteria operate optimally at scalding temperatures. If you were to cycle a DNA, enzyme (DNA polymerase), nucleotide, and primer mix many dozens of times to nearly the temperature of boiling water you would inactivate (denature) the DNA polymerase and fresh enzyme would have to be re-entered for each cycle. Using DNA polymerase from these bacteria allows one to continue the reaction through many cycles with just the original mix of reactants and enzyme.

All members of a group of ornithologists studying barn owls in the wild have had salmonellosis (Salmonella gastroenteritis). One birder is experiencing her third infection. What is the most likely source of their infections?

They are contaminating their hands while handling the owls and nests.

Which of the following is not a distinguishing characteristic of prokaryotic cells?

They lack a plasma membrane.

Which of the following is false about fimbriae?

They may be used for motility.

Clostridium botulinum is a strict anaerobe; that is, it is killed by the molecular oxygen (O2) present in air. Humans can die of botulism from eating foods in which C. botulinum is growing. How does this bacterium survive on plants picked for human consumption? Why are home-canned foods most often the source of botulism?

This soil bacteria produces spores that can survive extreme environments (including ones containing O2). Home canned foods are most often the cause of botulism poisoning because if the heat 'sterilization' is incomplete the spores may survive, O2 is driven off allowing the spores to germinate into vegetative cells, and most microbial competitors are killed so the food does not seem to be spoiled. If the toxin laden food is eaten without prior heating - just 3 minutes of boiling (which would destroy the protein toxin, it would be unnecessary to kill the spores, our normal flora keeps them at bay) you are in trouble.

particularly destructive to the developing fetus. normal pathogen of domestic cats

Toxoplasma gondii

Transfer of DNA from a donor to a recipient as naked DNA in solution.

Transformation

Electrons are refracted through a very thin specimen, 2-D image

Transmission electron

Usually sexually transmitted without serious symptoms

Trichomonas vaginalis

Biogenesis

True

Germ theory of disease

True

True or false, some microbes are able to fix nitrogen

True

Protozoa

Unicellular, complex cell structure lacking a cell wall

Prions cause

Untreatable, fatal, neurodegenerative disease in mammals

First to describe microbes

Van Leeuwenhoek

Thermal death point is not considered an accurate measure of the effectiveness of heat sterilization. List three factors that can alter thermal death point.

Variables that affect determination of the thermal death point are -The innate heat resistance of the strain of bacteria -The past history of the culture, whether it was freeze-dried, wetted, etc. -The clumping of the cells during the test -The amount of water present -The organic matter present -Media and incubation temperature used to determine viability of the culture after heating

1. The ecology class spends a lot of time in Tyler Park doing their thing. One of the students is bit by a tick that picked up some Borrelia from a mouse that the tick was feeding on. The Borrelia continued growing in the tick's stomach before it bit one of the students from the Eco class who then developed Lyme disease. The mode of transmission for Borrelia is

Vector, biological

Studies the causative agent of Ebola virus disease

Virology

No cell wall, in fact not a cell

Virus

Why do we classify viruses as obligatory intracellular parasites?

Viruses absolutely require living host cells to multiply.

which of the following is not true about viruses?

Viruses use their own catabolic pathways for ATP production

Which statement best describes what happens when a gram-negative bacterium is placed in distilled water and penicillin?

Water will move into the cell.

4. Place a + if the characteristic is one of a Gram + cell, and a - if it is characteristic of a Gram - cell _____Thick peptidoglycan _____Thin peptidoglycan _____Lipid A _____LPS _____Lipopolysaccharide _____Outer membrane _____Teichoic acids _____Stains purple in a Gram stain _____Stains red in a Gram stain

___+__Thick peptidoglycan ___-__Thin peptidoglycan ___-__Lipid A ___-__LPS ___-__Lipopolysaccharide ___-__Outer membrane ___+__Teichoic acids ___+__Stains purple in a Gram stain ___-__Stains red in a Gram stain

If ddC, is an anti-HIV medication that interferes with the DNA synthesizing enzyme of HIV and it resembles the normal nucleotide substrate for DNA synthesis - deoxy Cytidine then it must be

a competitive inhibitor

spontaneous generation is

a discredited idea that living things can arise from non-living materials

Which of the following is the most important element of Koch's germ theory of disease? The animal shows disease symptoms when

a microorganism is inoculated into the animal.

Which of the following is the best definition of respiration?

a sequence of carrier molecules with the final electron acceptor from the environment

Which of the following is the best definition of the Krebs cycle?

a series of chemical reactions in which NADH is produced from the oxidation of pyruvic acid

Which of the following does not initiate DNA synthesis?

a single-stranded RNA virus (Togaviridae)

a plasmid is

a small circular, autonomously replicating piece of DNA outside the chromosome of a bacterial cell (and some yeast)

Mycobacteria tuberculosis are particularly hard to kill and to stain because they have

a thick waxy cell wall

Flask A contains yeast cells in glucose-minimal salts broth incubated at 30°C with aeration. Flask B contains yeast cells in glucose-minimal salts broth incubated at 30°C in an anaerobic jar. The yeasts are facultative anaerobes. A. Which culture produced more ATP? B. Which culture produced more alcohol? C. Which culture had the shorter generation time? D. Which culture had the greater cell mass? E. Which culture had the higher absorbance?

a. A aerobic resp. 38, ferm. 2 b. B ferm. c. A by requiring nearly 20X fewer glucose molecules to get the same amount of energy flask A can grow very fast (a slow step in most processes is diffusion, and in principal flask B would have to diffuse 20X faster to keep up and it's not going to happen d. A will utilize the limited resource 20X more efficiently, will produce possibly 20X more cells (however, flask B will not utilizing its' energy source as efficiently does leave significant energy behind in its' fermentation product which can be used as a fuel, a food, an anesthetic or a party product e. A fig. 6.21 shows that more cells absorb and refract more light, less gets to light detector (a clever way to quantitate cells if you don't want to go to the trouble of counting them individually)

The prevalence of arthritis in the United States is 1 in 100,000 children. However, 1 in 10 children in Lyme, Connecticut, developed arthritis between June and September 1973. Allen Steere, a rheumatologist at Yale University, investigated the cases in Lyme and found that 25% of the patients remembered having a skin rash during their arthritic episode and that the disease was treatable with penicillin. Steere concluded that this was a new infectious disease and did not have an environmental, genetic, or immunologic cause. A.What was the factor that caused Steere to reach his conclusion? B. What is the disease? C. Why was the disease more prevalent between June and September?

a. Reducing a clinical symptom after use of anti-bacterial compound (penicillin in this case) is powerfully instructive. b. Lyme Disease. c. Ticks are a vector, summer months are the months that more people are outside potentially getting exposed to ticks..

Transformation

absorption and incorporation of new DNA sequences from an outside source

Which type of cell has a peptidoglycan associated with mycolic acid?

acid fast

A competitive inhibitor will bind

active site

A substrate will bind

active site

Where does a competitive inhibitor bind?

active site

Where does the substrate bind on the enzyme?

active site

What are the four nitrogenous bases of RNA?

adenine, guanine, cytosine, uracil

An organism that has peroxidase and superoxide dismutase but lacks catalase is most likely an

aerotolerant anaerobe

Grows as well in oxygen as in an anaerobic environment, has SOD, peroxidase

aerotolerant anaerobe

have SOD, have peroxidase, likely fermenters

aerotolerant anaerobes

Which disinfectant can be used also as an antiseptic and anesthetic?

alcohol (ethanol)

A feedback inhibitor will bind

allosteric site

Where does a non-competitive inhibitor bind?

allosteric site

Siderophores

allow absorption of an essential micronutrient

kinases and hyaluronidase

allow microbes to spread through the host

Mutation

alteration of existing DNA sequences

PCR

amplifies small amounts of DNA

Soap is best as a

an emulsifier for the removal of microbes

a pilus is

an extension from some cells from which DNA is passed from a donor cell to a recipient cell.

Reactions that require energy inputs, typically smaller molecules built into larger molecules

anabolism

Which one of the following diseases is not correctly matched to its reservoir?

anthrax—nonliving

Streptomycin, one of many agents isolated from Steptomyces, is a powerful anti-bacterial acting against the 70S ribosome. This substance can be best described as

antibiotic

passive immunity means

antibodies from one organism is transferred to another

elicits an antibody response

antigen

Which of the following is an example of bioremediation?

application of oil-degrading bacteria to an oil spill

opportunistic pathogens

are microbes that in their normal habitat in contact with a normal host do not cause disease

The type of protection provided by the injection of diphtheria toxoid.

artificially acquired active immunity

man gets a tetanus shot and then doesn't get tetanus

artificially acquired active immunity

The type of protection provided by the injection of antirabies serum.

artificially acquired passive immunity

man gets bit by a rabid raccoon and then is given injections of anti sera from a horse that has been immunized to rabies

artificially acquired passive immunity

Bacillus thuringiensis is a soil bacteria that is used

as a natural insecticide

Which of the following cannot be used to sterilize a heat-labile solution stored in a plastic container?

autoclaving

A drug that inhibits mitosis might be useful against all of the following (fungal, helminthic [worms] and protozoa) infections except which type?

bacterial

Why are there more effective anti-bacterial compounds as compared to other anti-microbials?

because bacteria cells have such profound biochemical differences to eukaryotic cells there are many reagents that are poisonous for bacterial cells but harmless to eukaryotic cells

Bacterial Meningitis is usually caused by microbes with which significant physiological feature?

capsule

slippery material to help cell escape phagocytosis

capsule

NADH and FADH2

carry high energy electrons from organic substrates

Reactions that release energy, typically larger molecules broken down into smaller molecules

catabolism

Which of the following is not an effect of complement proteins?

causes fever

strong rigid material responsible for protection agains osmotic lysis

cell wall

Bacterial Meningitis is always life threatening because

cell wall components like endotoxins are released as the cells die causing severe inflammation and shock

Plasma

cell wall formation and selective permeability

Bacteria

cell wall made of peptidoglycan

Eubacteria

cell walls made of peptidoglycan

spherical shaped cell

coccus

What best describes metabolism?

collectively, all the chemical reactions in a cell

Inhibits an enzyme by binding the active site (substrate binding site)

competitive inhibitor

a stained bacterial smear

compound light microscope

two magnifying lens

compound light microscope

lens system below stage that focuses light onto the specimen

condenser

Three-dimensional images of live cells can be produced with

confocal microscopy

unstained bacterial cells: the cells are small, and no detail is needed

darkfield microscope

number of cells decreases

death

Viroids cause

death of plants

agent to remove stain

decolorizer

It has been said that bacteria are essential for the existence of life on earth. Which of the following is the essential function performed by bacteria?

decompose organic material and recycle elements

What best describes catabolism?

degradation of organic molecules, releasing energy

IgA proteases

destroy an important host resistant factor (IgA antibodies)

controlling extension from the condenser system to increase or decrease amount of light reaching specimen

diaphragm

Lysozyme, found in perspiration, tears and saliva is protective against some Gram + bacteria because this protein

digests peptidoglycan

What is the mechanism of transmission for Chlamydia (Sexually transmitted) infection?

direct contact

Adding chlorine or bromine to a swimming pool is best described as

disinfection

Destruction or elimination of pathogenic vegetative cells

disinfection

Pasteurization can be best described as a

disinfection

An example of recombinant DNA technology would be

producing the Bacillus thuringensis insecticidal toxin in cotton plants

1. For a DS DNA virus place the following steps in order for the biosynthesis stage of the viral cycle. Capsid synthesis DNA replication early transcription

early transcription, DNA replication Capsid synthesis

Which of the following is not a modification of a compound light microscope?

electron microscopy

Lipid A from lipopolysaccharide from the outer membrane of Gram - bacteria is called

endotoxin

Based on the following information decide what type of medium is being described. Blood agar, tryptic soy agar supplemented with 5% sheep red blood cells, allows the growth of many more microbes than TSA. It is particularly good for growing out some of the microbes from the oral cavity that other wise would grow poorly on TSA.

enriched

rRNA

enzymatic (formation if covalent bonds between amino acids)

The chief purpose of the Krebs cycle is to

extract high energy electrons from organic molecules and place them on electron carriers

Grows better in oxygen than in an anaerobic environment, has SOD, catalase

facultative anaerobe

have SOD, have catalase, likely aerobic respires or fermenters

facultative anaerobes

Which of the following is not a property of inflammation?

fever (systemic increase in body temperature)

Patients in surgery often have their insides open to the outside and patients on respiratory therapy have air pumped into their lungs with a mechanical device. For both sets of patients it's a benefit to use sterilized air. The easiest way to sterilize air is to

filter it

Which sterilizing technique is best used on fluids (liquids and gases)?

filtration

short hair like filaments for attachment to surfaces

fimbriae

apply heat to cells to make them adhere to the glass slide

fix

long whip like appendage for motility

flagella

sputum stained with auramine O

fluorescent

The chromosome of a virus can be

for some viruses DNA for others RNA never both

Antibiotics should be taken

for the fully prescribed amount of time no matter what the improvement in the symptoms of the patient

Ionization radiation is sterilizing because

formation of hydroxyl radicals occurs which damages the cell beyond repair

A mutagen that causes insertions

frameshift mutation

If a molecule or an atom has been reduced it has

gained an electron

Transducing particle requires host cell enzymes to recombine new DNA into host chromosome

generalized

Which of the following is false about ATP synthase

it participates in a catabolic reaction

Which of the following is the starting substrate for glycolysis?

glucose

The starting and ending materials for glycolysis are

glucose, pyruvic acid

small molecular weight molecule that must be attached to a larger molecule to elicit and antibody response

hapten

virus

has only one type of nucleic acid has a capsid one step growth curve

Which of the following is not a characteristic of bacteria?

have the same shape

Most common, most simple, most used sterilization technique?

heat

Staphylococcus aureus is implicated in a number of different infectious diseases. One illness that it is responsible for however, is an intoxication and not an infection. This microbe is often unrecognized in food because the food is partially preserved and does not allow much growth of other microbes that would tip off the diner to spoilage (off smells and off colors). What preserving property of some foods are the staphylococci resistant to?

high osmotic pressure

the reservoir for the hepatitis C virus is?

humans

For each of the following bacteria, explain why it is often resistant to disinfectants. Mycobacterium Pseudomonas Bacillus

i. Mycobacterium This genus belongs to the acid fast group. They have a particularly thick (Gram + really) cell wall that is permeated with mycolic acids which are very waxy making these cells somewhat impermeable to disinfectants, antiseptics and antibiotics.ii. Pseudomonas This genus of bacteria is in the Gram - family of bacteria. It has a number of features that protects it from assault. First, its' outer membrane while protective of Gram - bacteria in general in this genus is particularly impermeable to noxious agents.Second, this bacteria has an efflux system to pump out any noxious agents that are able to penetrate into the cell.Third, these bacteria have unusual metabolic pathways that can actually utilize some disinfectants as an energy and/or carbon source. While these bacteria (Pseudomonas) are formidable opponents they tend to not cause very much infection in normal healthy hosts. Notable exceptions are burn patients that are very susceptible to Pseudomonas aeruginosa. This is the reason that flowers and plants are not allowed in the burn unit. This bacteria is a normal soil bacterium and often will be on plant material. The other likely hosts are cystic fibrosis patients. Because of the particular disturbance of lung physiology these bacteria can colonize and cause a huge problem that is very resistant to antibiotic therapy. In fact identification of Pseudomonas aeruginosa in the lungs is diagnostic for CF. iii. Bacillus is a spore forming group. The bacterial endospores are the most difficult of cells to destroy. It is because of these cells that we need to go to such extreme measures for sterilization.

What is the physical composition of a viral envelope? Why is it not considered to be a 'membrane'?

i. Phospholipid bilayer (Plasma membrane but for Herpes virus they take the nuclear membrane), viral spike proteins ii. functionally not a membrane, it is inert

Determining the particular strain of a microbe is important. One way of doing this is by phage typing. Phage typing

identifies a particular bacterial strain by showing the specific pattern of sensitivity to bacterial virus attack

Studies the symptoms of AIDS

immunology

Multiple drug resistant Staphylococcus aureus are more likely to be found in health care settings because

in health care settings the microbe is often under antibiotic attack which kills off most sensitive portion of the microbial population leaving the more resistant portion to proliferate

Some harmful algal blooms (HABS) are clearly the result of human activity are most common in summer time. Fertilizer run off from lawns and agricultural fields are rich in the macronutrients phosphate and nitrate. In many coastal communities, including the Chesapeake Bay restrictions on use of these fertilizers has had a dramatic effect in improving the water quality. Ironically, these same compounds are deliberately applied to marine oil spills. The oil is very rich in carbon and hydrogen but deficient in nitrogen and phosphorous. Bacteria found naturally in the marine environment are given a boost in their growth potential by adding the limiting nutrients. What effect do you predict global warming will have on HABS?

increase HABS

mRNA

information molecule that is translated

Which of the following modes of action would not be fungicidal?

inhibition of peptidoglycan synthesis

Select the correct energy and carbon sources for a chemoautotroph. Answers are in the following format: energy source, carbon source

inorganic molecule, carbon dioxide

protects against viruses

interferon

cytokines that signal a white blood cell

interleukin

Which of the following is most likely to be bactericidal?

ionizing radiation

Which sterilizing technique causes highly destructive hydroxyl radicals to form?

ionizing radiation

Saccharomyces

is a yeast used for making beer, wine and bread

Nitrogen fixation means that nitrogen is

is changed from the elemental form to a compound that can be used by other living things

In aerobic respiration, pyruvic acid

is oxidized to acetyl Co-A

It is possible to purchase the following microorganism in retail store. Provide a reason for buying it Bacillus Thuringiensis

is sold as a biological insecticide

It is possible to purchase the following microorganism in retail store. Provide a reason for buying it Saccharomyces

is the yeast sold for making bread, wine and beer

Which of the following is not correct about a moderate fever?

it is bad because it causes host cell destruction

anaerobic respiration

less than 36 ATP

Which of the following is the fourth basic step to genetically modify a cell?

ligation

light bulb at the base of the microscope

light source

Select the correct energy and carbon sources for a photoautotroph. Answers are in the following format: energy source, carbon source

light, carbon dioxide

photoheterotroph carbon source, energy source

light, inorganic molecules

Normal microbiota (or normal flora) are microbes that

live in or on a human helping us maintain health

the number of cells expands geometrically

log

Which is not a non-specific host defense?

lowering blood pressure

the number of times larger an image is compared to the object

magnification

Collectively, all of the reactions in the cell

metabolsim

the germ theory of disease was an important philosophical shift in thinking. This idea. simply, is

microbes cause disease

Probiotics are

microbes that are ingested to antagonize pathogens

Develops gene therapy for a disease

molecular biology

additive that enhances stain property

mordant

Helminths

multicellular animals

both partners benefit

mutualism

Studies the fungus Candida albicans

mycology

The type of protection resulting from recovery from an infection.

naturally acquired active immunity

woman had chicken pox as a child and is now immune as an adult

naturally acquired active immunity

A newborn's immunity to yellow fever.

naturally acquired passive immunity

baby is protected from diarrhea by nursing

naturally acquired passive immunity

Based on the following information decide what type of medium is being described. TSA, tryptic soy agar allows the growth of many non-fastidious (not fussy) microbes

neither selective nor differential

Archaebacteria

prokaryotes with cell walls but not composed of peptidoglycan

magnifying lens coming out of the nose piece

objective lens

Only grows in oxygen, has SOD, catalase

obligate aerobe

have SOD, have catalase, likely aerobic respire

obligate aerobes

Dies in the presence of oxygen, lacks SOD, catalase and peroxidase

obligate anaerobe

lack SOD, lack catalse. lack peroxidase, likely fermenters

obligate anaerobes

magnifying lens near where the eyes are placed

ocular lens

Parasitism

one benefits and the other is harmed

Commensalism

one benefits and the other is unaffected

enhances phagocytosis

opsonin

Select the correct energy and carbon sources for a chemoheterotroph. Answers are in the following format: energy source. carbon source

organic molecules, organic molecules

All of the energy-producing biochemical reactions that occur in cells, such as photophosphorylation and glycolysis, are _______reactions.

oxidation

Loss of one or more electrons, loss of some energy status

oxidation

Why does oxygen kill obligate anaerobes?

oxygen accidentally gets reduced forming a highly reactive and destructive reactant

One partner benefits, the other is negatively affected

parasitism

the envelope of a virus is made up of

partly the membrane of the host and partly viral proteins

Restriction enzymes were first discovered with the observation that

phage DNA is destroyed in a host cell.

appendages used for transferring DNA from one cell to another

pili (conjugation pili)

A small double stranded circular extra chromosomal element that is useful in genetic engineering of bacteria is

plasmid

A potent methodology for identifying strains of microbes in serology. This process requires

pre-formed antibodies taken from an animal that was immunized to a particular strain of microbe

The capsid coat of a virus is made up of what material?

protein

endotoxins which can be found in Gram + or Gram - bacteria is easily denatured by heat because it is

protein

Ribosomes

protein synthesis

PRIONS are remarkable in that they are only comprised of

proteins

antibodies can best be described as being

proteins

Shortwave UV may cause so many mutations, the repair mechanisms of the cell may be so overwhelmed that the cell will not be able to recover and it dies. What particular nucleotide combinations are most susceptible to UV damage?

pyrimidine dimers; TT, CC, TC, CT

antibiotics and vaccines are best sterilized by

radiation or filtration

Manipulation of microbes to take on a human gene and synthesize a protein like human growth hormone is an example of

recombinant DNA technology

Gain of one or more electrons, gain of some energy status

reduction

feature of light that describes its path change as it moves from one medium to another

refraction

An envelope is acquired during which of the following steps?

release

Endotoxin has low toxicity, however, when their is a septicemia (infection of the blood) there is so much bacteria that are being lysed either by the action of your immune system or due to the action of antibiotics that the toxin can kill. The action that causes death is by

release of immune factors that can cause lethal shock.

capsules, M proteins of Streptococcus pyogenes and A protein of Staphylococcus aureus

resist phagocytosis

An encapsulated bacterium can be virulent because the capsule

resists phagocytosis

ability to discern as separate objects two things, set close together

resolution

DNA polymerase

synthesizes a complementary, anti-parallels DNA

Based on the following information decide what type of medium is being described. MSA, mannitol salt agar allows the growth of halophilic microbes only. Those halophiles that do grow will cause a yellow coloration of the medium surrounding the bacterial growth if they are able to ferment the sugar mannitol. Non-fermenters are unable to change the color of the medium.

selective and differential

Streptococcus pyogenes is responsible for rheumatic fever, Paradoxically, the disease is not simultaneous with the infection but follows the infection. This because

self-made antibodies against the microbe cross react with the host tissue, as the maximal concentration of these proteins is reached, the microbe is eliminated but the toxic effect of the host proteins persists causing the disease.

An indirect method for identifying a microbe is by examining the specificity of anti bodies in a patient. This type of analysis is called

sera typing

what type of chromosome does a +Rna virus have?

single stranded mRNA

plasmid

small circular DNA molecule

The term trace elements refers to

small mineral requirements.

a monolayer spread of cells on a microscope slide

smear

Bacteria can acquire antibiotic resistance by all of the following except

snRNPs.

Transducing particle will automatically integrate DNA into new host cell

specialized

In aerobic respiration

spent electrons from the electron transport chain are deposited onto oxygen and water is formed

rigid spiral shaped cell

spirillum

spiral shaped with axial filament

spirochete

colored agent to allow better visualization

stain

grape-like clusters of spherical cells

staphylococci

number of cells in the population remains constant

stationary

linear chain of spherical cells

streptococci

Which of the following would not be a desired characteristic of a chemotherapeutic drug?

strong microbial resistance to the agent

What best describes anabolism?

synthesis of large molecules from smaller precursors, energy requiring

Assume you inoculated 100 facultatively anaerobic cells onto nutrient agar and incubated the plate aerobically. You then inoculated 100 cells of the same species onto nutrient agar and incubated the second plate anaerobically. After incubation for 24 hours, you should have

the same number of colonies on both plates.

Genus Bacillus is difficult to kill because

these cells produce endospores

which of the following is a characteristic of plasma cells?

they produce and secrete antibodies

Which of the following is not a property of phagocytic cells?

they produce antibodies and complement proteins

If you put a gene in a virus, the next step in genetic modification would be

transduction

Transfer of DNA from a donor to a recipient cell by a bacteriophage.

transduction

conjugation

transfer of DNA directly from one cell to another

Transduction

transfer of DNA from one cell to another by a bacteriophage

what is the first biosynthetic event after uncoating for a +RNA virus?

translation

tRNA

transport molecule (transports amino acid to ribosomes)

Staphylococcus aureus is easily transmitted around health care facilities because

un-identified healthy carriers (health care workers and patients) can spread the microbe to others that can then develop disease symptoms

Break the hydrogen bonds in the DNA double helix

unwinding proteins

When a microbe is presented with multiple carbon sources, it will generally

utilize the one that yields the fastest log growth first

Borrelia burgdorferi causes Lyme disease in humans, an accidental host. The normal host is deer and deer mice. Ticks carry the microbe from one host to another including the accidental host. What is the mode of transmission for the disease?

vector

Salmonella Saint Paul is an unusual strain that has sickened many people in the US in the Spring of 2008. It is believed that a common source of transmission has been tomatoes from Mexico or Florida. What is the likely mechanism of transmission?

vehicle

Vibrio cholera causes a potent diarrheal disease in humans. It is not known to grow anywhere else. The bacteria can accumulate in shellfish that has been contaminated with human waste. Many people can get sick from eating raw or undercooked shellfish. The mode of transmission is

vehicle

Interferons are predominantly effective against

viruses

Many foods are preserved because they have a lot of salt or sugar in them (e.g., candy, salt cured hams, honey). Microbes are unable to grow on these foods because

water leaves the cells, dehydrating them

If a bacterial cell with an intact cell wall is placed in distilled water (highly hypotonic) the following would result

water would diffuse into the cell until such a time that back pressure from within the cell would halt any further entry of

If a human red blood cell (unprotected by a cell wall) is placed in distilled water (highly hypotonic) the following would result

water would diffuse into the cell until the cell lysed

feature of light that describes the distance between two successive waves

wavelength

Wet heat is more efficient than dry heat because

wet heat transfers the heat more efficiently