Final Exam Homework Questions

A periplasmic space is found in which of the following? Gram negative cells only

A bacterial cell stains positive with the acid-fast stain. Which of the following is FALSE? It may be a member of the genus Mycobacterium. **It has a cell wall that contains endotoxin. It will be difficult to stain this cell with the Gram stain. It has a cell wall that contains waxy lipids.

All of the following are components of an amino acid EXCEPT a(n) R group. **pentose group. amino group. α-carbon. carboxyl group.

A macromolecule containing two fatty acids and a phosphate group is a phospholipid

What does a spectrophotometer measure? turbidity

A medium that supports the growth a few types of microorganisms and prevents the growth of other types of microorganisms is a(n) selective media

Microbiologists study only single-celled organisms. false

A microbe with a cell wall and no internal membrane enclosing the DNA is a prokaryote. true

Metabolic activity is at maximum level in the ________ phase of growth. log

A microorganism found living under conditions of high ________ is a barophile hydrostatic pressure

Which of the following is one-billionth of a meter? nanometer

A scientist is using an objective lens with 40× magnification on his microscope. If the ocular lens magnifies 10×, what is the total magnification being used to visualize the specimen? 400x

Thermoduric mesophiles are often responsible for spoilage of improperly canned foods true

Agar is a useful compound in the microbiology lab because it is an excellent nutrient for bacteria. false

Enzymes are catalysts that speed up chemical reactions as a function of their ability to __________. lower the activation energy of the reaction

All of the following are false regarding enzymes except? **Apoenzymes may need to combine with cofactors or coenzymes to become active. Enzymes bind substrates at their allosteric sites. Enzymes are broad acting and can bind a wide variety of substrates. Enzymes increase the activation energy required for a chemical reaction to occur.

Which of the following generates amino acids from metabolic pathway intermediates and NH3? amination

All of the following are incorrect EXCEPT? The apoenzyme is a combination of a cofactor and with its cognate holoenzyme. All enzymes have cofactors necessary for activation. Enzymes can function at a wide range of pH. Competitive inhibition of an enzyme results from binding of an allosteric site by an inhibitor. **Following a chemical reaction an enzyme resumes its original shape and can interact with a new substrate molecule.

During Chemiosis What produces the energy to catalyze the production of ATP from ADP and inorganic phosphate? proton gradient

All of the following are pathway:intermediate pairings are correct EXCEPT? the Krebs cycle: oxaloacetic acid **electron transport: acetyl-CoA chemiosmosis: ATP synthase glycolysis: glucose 6-phosphate

All of the following serve as electron acceptors of anaerobic respiration EXCEPT? oxygen

All of the following are possible end products of fermentation EXCEPT? glucose

Which of the following individuals pioneered the use of chemicals to reduce the incidence of infections during surgery? Lister

All of the following were involved in developing the germ theory of disease EXCEPT Pauling

Compounds that readily dissociate in water are polar or ionic

An acid dissociates in water to release both anions and hydrogen ions.

Physical removal of microbes without killing them is degerming

An antimicrobial agent that ________ will have the most lasting germicidal effect. damages DNA

Antimicrobial agents that damage nucleic acids also affect protein synthesis

An instrument that will come into contact with only the skin of a patient should be disinfected with a low level germicide

When the nucleus of an atom contains a constant number of protons but a variable number of neutrons, the atom is called a(n) __________. isotope

An oxygen atom has two electron shells and 6 valence electrons. How many total electrons does this atom have? 8

Which of the following lipids has the lowest ratio of hydrogens to carbons? polyunsaturated fats

Anna is conducting an experiment using a pH indicator that is red at low pH, green at neutral pH, and purple at high pH. She starts with a green solution. When she adds compound X to her solution it turns purple. Then she adds compound Z to the solution and it turns green. She adds more Z and the solution remains green. These observations suggest X is ________ and Z is ________. a base a buffer

A nurse preparing a section of skin for an injection is an example of _________ degerming

Antimicrobial agents that damage the viral envelope __________. prevent attachment of the virus to its target cell

Which technique is the most useful for measuring bacteria reproduction when the density of a population is very small relative to the environment? membrane filtration

At which phase of a bacterial population growth curve is the growth rate optimum? log phase

MacConkey agar plates represent ________ medium. differential and selective

Bacterial binary fission results in ________ growth. exponential

DNA is composed of repeating units of sugars, phosphates, and nucleic acids. This is an example of a polymer

Bacterial cell walls are composed of peptides and polysaccharides

A synthesis reaction is also considered which of the following types of reactions? endothermic

Catabolism includes all of the following types of reactions EXCEPT __________. dehydration synthesis reactions

All of the following are differences between eukaryotic and bacterial gene expression EXCEPT? Eukaryotic RNA is modified prior to translation, whereas bacterial RNA is not. ** Initiation of translation in bacteria occurs when the ribosomal subunit binds to the 5' guanine cap, while in eukaryotes it binds to a specific nucleotide sequence. Bacteria may have genes organized and regulated within operons, while eukaryotes lack operons. Bacteria have 70S ribosomes, while eukaryotes have 80S ribosomes in their cytoplasm.

Conjugation between two bacteria is facilitated by which of the following? conjugation pilus

An antimicrobial chemical used on the skin is usually called __________. antiseptic

Damage to the cell wall will adversely affect a bacterial cell by making it more susceptible to __________. osmotic pressure

Which of the following is characteristic of proteins? They have multiple layers of structural organization

Decomposition reactions are commonly ________ reactions. exothermic

The term that literally means "against putrefaction" is antisepsis

Edward Jenner's efforts to prevent smallpox provided the foundation for the field of immunology

Which of the following is not a catabolic reaction? the conversion of glucose to starch

Enzymes speed up the rate at which chemical reactions occur within a cell because the enzyme __________ lowers the activation energy of the reaction

Which of the following pathways produces the most types of metabolites for anabolic pathways? pentose phosphate

For obligate aerobic organisms that do not use photosynthesis how is the majority of their ATP is generated? oxidation-reduction reactions

Loss of a functional pilus gene will result in an inability of bacterium to perform which of the following functions? conjugation

Frederick Griffith's experiments with Streptococcus pneumoniae demonstrated which of the following? He showed that the DNA from strain S cells could transform strain R cells.

Which of the following is a low-level disinfectant? quats

Hydrogen peroxide does NOT make a good antiseptic for open wounds because __________. catalase in human tissues neutralizes it

Alcohols are used for both antisepsis and disinfection.

Hydrogen peroxide is NOT an effective antiseptic because the catalase present in skin cells degrades it

Which of the following could be used to sterilize objects such as medical devices? ethylene oxide

Hydrogen peroxide is an example of __________ and can serve as an effective disinfectant, though it does NOT work well as an antiseptic. an oxidizing agent

Robert Koch's contributions to the foundations of modern microbiology include developing methods for isolation and identification of bacteria.

Identification of bacteria in the laboratory usually begins with the ________ for placement in one of two large groups of bacteria. Gram stain

An endothermic reaction __________. requires energy

If you know that a particular chemical reaction involves the production of smaller molecules from the breakdown of larger molecules, which of the following statements would you expect to be true? The reaction releases energy

Which of the following is a bond in which electrons are shared unequally? polar covalent

If you know that sodium chloride molecules contain ionic bonds, which of the following electronegativity values would you consider appropriate for the elements sodium and chlorine? .9 and 3

Joseph Lister reduced the incidence of wound infections in health care settings by using chlorinated lime water. false

In discussions of atomic mass, electrons are often ignored because their mass makes a negligible contribution to the atom's overall mass

Which of the following is the preferred method of determining the efficacy of an antimicrobial chemical in the European Union? Kelsey-Sykes capacity test

Iodophors and chloramines are similar in that they are both halogen-containing compounds that __________. slowly release their active ingredients

Fermentation requires the presence of living cells. false

Koch's postulates can be used only to determine the causes of infectious diseases. true

The terminal electron acceptor of the electron transport chain of cellular respiration is which of the following? oxygen

Low pH and high temperatures inhibit enzymatic activity by which of the following mechanisms? Changes in pH and/or temperature can cause an enzyme to lose its precise 3D shape

Which of the following pathways utilizes acetyl-Co-A as a substrate? Krebs cycle

Match the function of a lipase with its substrate. **catabolism; fats catabolism; carbohydrates anabolism; carbohydrates anabolism; fats

The microbes commonly known as ________ are single-celled eukaryotes that are generally motile protozoa

Microorganisms characterized by the absence of a nucleus are called prokaryotes

Which of the following is NOT an example of ionizing radiation? UV light

Milk that can be stored for months at room temperature has been treated by which of the following methods? ultrahigh-temperature sterilization

Denaturation of a protein is always permanent. false

One of the products of dehydration synthesis reactions is water true

A fastidious organism might be grown on which of the following types of media? enriched media

Organisms that can grow with or without oxygen present are either facultative anaerobes or aerotolerant anaerobes

A microbiologist is using heat to drive the stain carbolfuchsin into a smear. Which of the following staining procedures is the microbiologist using? acid fast

Plaques are associated with which of the following methods of laboratory identification of microorganisms? phage typing

A food product is labeled as having antioxidants. It may therefore contain vitamin C or E, or both.

Prokaryotes living in the ocean around volcanic vents use the volcanic gasses carbon dioxide (CO2) and hydrogen sulfide (H2S) to fuel their metabolism. They are therefore lithoautotrophs

Tertiary and quaternary structure of proteins involves ________ bonds. hydrogen, ionic, polar, and nonpolar covalent

Proteins contain both acidic and basic R groups, and can therefore function as buffers

All of the following are sources of organic acids EXCEPT __________. baking soda

Pure water has a neutral pH because __________. it dissociates into equal numbers of hydrogen and hydroxyl ions

Which of the following is a CORRECT pairing of metabolic terms? **hydrolysis: decomposition synthesis: exothermic catabolism: endothermic dehydration: decomposition synthesis: catabolism

Serine+ATP --> Serine P+ AMP exchange reaction

Which of the following CANNOT be used to definitively identify bacteria? disease symptoms

Staining is an important way to improve which of the following aspects of microscopy? resolution and contrast

Deletions or insertions usually result in which of the following types of mutations? frameshift mutations

The Ames test involves mutants of Salmonella that __________ the ability to make histidine in the __________ of a suspected mutagenic chemical. gain, absence

________ may be achieved using chlorine dioxide. disinfection

The compound ethylene oxide is used in sterilization

The term for the use of microorganisms to restore damaged environments is bioremediation

The control of infectious disease remains challenging a century after the understanding of infectious disease began. What contributes to the continuing challenge? both drug-resistant pathogens and emerging diseases

Amylose is a(n) ________ carbohydrate. polymer

The electron shells of atoms hold eight electrons each. false

A bacterial cell possesses a glycocalyx. Which of the following is FALSE? It will be less likely to dry out. **It will be engulfed more quickly by defensive cells of the host. It will be more pathogenic. It will be able to attach to surfaces.

The filament and basal body are associated with which of the following external structures found in some bacterial cells? flagella

Archaeal flagella __________. rotate as bacterial flagella do

The hami of some archaea are used for which of the following processes? attachment

Which of the following is NOT a component of eukaryotic cell walls? sterols

The process of bringing a solid substance into the cell is known as __________. phagocytosis

Where do you find the photosystems in photosynthetic organisms? thylakoids

The products of βeta-oxidation are substrates for which of the following? Krebs cycle

The type(s) of bond produced when atoms with somewhat different electronegativities share electrons is/are a polar covalent bond.

The type(s) of bonds produced when atoms share electrons equally is/are nonpolar covalent bond

During DNA replication the enzyme responsible for unzipping the DNA molecule is called ___________. DNA helicase

What causes the formation of Okazaki fragments during DNA replication? is discontinuous on the lagging strand

In the symbol R-OH, the "R" stands for the __________ part of the molecule variable

What is the common trait of all lipids? They are at least partially hydrophobic

Which of the following scientists provided evidence in favor of the concept of spontaneous generation? Needham

What is the correct order for the steps in the scientific method? I. Conduct experiment. II. Develop a hypothesis. III. Analyze results. IV. Accept or reject hypothesis. II, I, III, IV

Why do some microorganisms have to be cultured in living animals? Standard laboratory culture techniques have proven inadequate.

What is the most common technique for isolating microorganisms in laboratories? streak plate method

Whose search for chemicals that would kill microbes without harming humans was the foundation for chemotherapy? Ehrlich

What scientist first hypothesized that gene sequences could provide new insights into evolutionary relationships among all organisms (including microbes)? Pauling

The use of viruses to introduce foreign DNA into bacteria is called _________________. transduction

What type of mutation results in the replacement of an amino acid encoding codon with a stop codon nonsense mutation

During which growth phase do antimicrobial drugs have the greatest inhibitory effect? log phase

When cells are metabolically active but not dividing, they are in the ________ phase. lag phase

What is generated from the production of acetyl-CoA from pyruvic acid? NADH

When isomerases catalyze reactions what occurs? atoms in molecules are rearranged.

One of the pathways listed below yeilds the greatest amount of NADH, but the least amount of ATP. Which one is it? Krebs cycle

When the end product of a chemical reaction inhibits the enzyme that catalyzes the reaction itself, that is an example of __________. feedback inhibition

Which of the following uses inorganic phosphates? oxidative phosphorylation and photophosphorylation

Where is Chlorophyll found in photosythetic organisms prokaryotic organisms? infoldings of the plasma membrane

A broth containing one million bacterial cells is treated with an antimicrobial agent that kills 90% of the cells in 1 minute. What is the minimum amount of time it will take before all the cells in the broth are dead? 7 minutes

Which biosafety level requires that laboratory air be HEPA-filtered but is insufficient for the safe study Ebola? BSL 3

A hydroxyl ________ acts as a base. anion

Which of the following are examples of pyrimidines? cytosine and thymine

Which of the following techniques can be used to sterilize microbiological media? autoclaving

Which of the following could be used to sterilize a heat-sensitive liquid such as urea broth? filtration

What is an example of a negative stain? capsule

Which of the following does NOT stain the bacterial cell? negative stain

Which of the following is NOT a basic process of life? sexual reproduction

Which of the following is NOT a characteristic of a eukaryotic cell? presence of a nuclear envelope **can undergo transcription and translation simultaneously presence of membrane-bound organelles contain chromosomes composed of DNA and histones

Parasitic worms, even meters-long tapeworms, are studied in microbiology because diagnosis usually involves microscopic examination of patient samples.

Which of the following is NOT a characteristic of protozoa? they are single-celled organisms. most exhibit asexual reproduction. they frequently possess cilia or flagella. they are eukaryotic organisms. **they are all photosynthetic.

In a hypotonic environment, the volume of a plant cell enlarges as the cytoplasm pushes against the cell wall. Which organelles are most likely able to store that extra water? vacuoles

Which of the following is NOT a membranous organelle within a eukaryotic cell? ribosomes

What is the name of the bond that forms the primary structure of a protein? peptide bond

Which of the following is NOT a type of lipid? peptidoglycan

Pasteur's experiments on fermentation laid the foundation for industrial microbiology

Which of the following is NOT an observation Pasteur made concerning the fermentation of grape juice? pasteurization kills yeast to prevent spoilage of grape juice.

Which of the following statements about fungi is INCORRECT? fungi have a cell wall. molds are multicellular. fungi are eukaryotes. yeasts are unicellular. **fungi are photosynthetic.

Which of the following is an accurate description of viruses? they are acellular obligatory parasites.

At the max growth temp of a bacterium which of the following doesn't happen? Membranes become rigid and fragile.

Which of the following is characteristic of a haploid cell? a single copy of each of its chromosomes

Put the following microbes in order of their resistance to antimicrobial agents, from least to most resistant: a. prions b. enveloped viruses c. mycobacteria d. bacterial endospores bcda

Which of the following is most susceptible to antimicrobial agents? vegetative bacteria

What is a CFU (colony-forming unit)? a single cell or group of related cells that gives rise to a colony

Which of the following is sheep's blood agar an example of? a differential medium and a complex medium

The process preformed by the enzyme RNA polymerase is called __________. transcription

Which of the following is the entry site for the first amino acid (fMet) in the ribosome during bacterial RNA translation? P site

Compared to moist heat methods, dry heat needs which of the following in order to sterilize effectively? higher temperature and increased time

Which of the following is the most important part of sterilization using an autoclave? increased pressure

Antoni van Leeuwenhoek was the first person in history to view microorganisms and record these observations

Which of the following microbes are likely to be the swiftly moving "animalcules" observed by Leeuwenhoek in pond water? protozoa

The end products of which of the following processes are H2O, O2, and C6H12O2? photosynthesis

Which of the following most likely determines the conditions under which a photosynthetic organism lives? chlorophylls it produces

A cell that uses an organic carbon source and obtains energy from light would be called a photoheterotroph

Which of the following oxidizing agents is sometimes produced during aerobic respiration? superoxide radical

A bacterial cell is placed in distilled water. Which of the following will happen? the cell will gain water

Which of the following processes can be either specific or nonspecific depending upon the particular molecules that are transported? facilitated diffusion

Louis Pasteur demonstrated that fermentation to produce alcohol is caused by facultative anaerobes

Which of the following question largely stimulated the research of microbes during what is known as the Golden Age of Microbiology? What causes disease, and is spontaneous generation of microbes possible?

Which of the following would distiguish a prokaryotic chromosome from a eukaryotic chromosome? circular molecule

Which of the following statements best describes the function of the lactose (lac) operon? It ensures that bacteria only make the enzymes to catabolize lactose when lactose is present.

Which of the following is found only in eukaryotic cells? nuclear envelope

Which of the following statements concerning the characteristics of life is FALSE? eproduction can occur asexually or sexually in living things. organisms may not exhibit all of the characteristics of life at all times. living things store metabolic energy in the form of chemicals such as ATP. **reproduction is defined as an increase in the size of an organism. viruses have some, but not all, of the characteristics of living things.

Which of the following antimicrobial agents is the most toxic to humans? ethylene oxide

Which of the following statements is TRUE of disinfectants? They are used for sterilization. They are only effective for short periods of time (seconds to minutes). They are used on living tissue. They are effective in destroying endospores. **They are used on inanimate surfaces.

Leeuwenhoek's microscopes had a resolution (resolving power) of 1 micrometer. This means that __________. the microscope could distinguish objects that were more than 1 micrometer apart

Which of the following types of microscopes can magnify more than 2000×? a transmission electron microscope

What is produced from the break down of proteins? ammonia

Which of the following uses oxygen to generate a proton gradient? photosystem II

PHB is NOT associated with which of the following words? ribosome

Which of the following would NOT be found in the cytoplasm of a bacterial cell? ribosomes nucleoid endospores **porins

All of the following are associated with ATP molecules EXCEPT formation of coenzymes. **a long-term energy supply. high-energy bonds. a recyclable energy supply. three phosphate groups.

Which parts of the atoms interact in a chemical reaction? electrons

Who among the following may be considered the Father of Microbiology in part because of his careful application of the scientific method to many problems in microbiology? Louis Pasteur

Who demonstrated that fermentation could occur in the absence of intact cells? Buchner

Paul Ehrlich used chemotherapy to treat syphilis

Who discovered penicillin? Fleming

Which of the following describes flash pasteurization? heating at 72°C for 15 seconds

Why is Bacillus stearothermophilus useful as an indicator of sterility? It forms endospores, among the most hardy of microbial contaminants

At temperatures higher than the maximum growth temperature for an organism hydrogen bonds are broken, proteins are denatured, and membranes become too fluid

You open a jar that has been in the refrigerator for a couple of weeks and find the contents do not look or smell right. What type of microbe has been growing in your refrigerator? psychrophile