Microbiology Exam 1

Which of the following is true about glycolysis: A. Glycolysis catabolizes glucose generating 4 ATP and 2 acetyl-CoA B. Glycolysis is utilized only during fermentation, and never during aerobic respiration. C. Glycolysis requires 2 ATP and generates 4 ATP, for net gain of 2 ATP per glucose molecule catabolized. D. The co-enzyme FAD+ is required for glycolysis.

C. Glycolysis requires 2 ATP and generates 4 ATP, for net gain of 2 ATP per glucose molecule catabolized.

Mannitol Salts Agar contains mannitol, phenol red, and 7.5% sodium chloride. The high salt concentration inhibits the growth of most bacteria other than Staphylococcus species. Staphylococcus aureus can ferment mannitol lowering the pH of the surrounding media resulting in a color change to yellow. Other species of Staphylococcus do not ferment mannitol, and thus the media retains a red color. Mannitol Salts Agar is a: A. differential media B. selective media C. synthetic media D. Both differential and selective media.

D Both differential and selective media

Catabolism is : A. all of the biochemical reactions taking place in an organism. B. all of the energy releasing biochemical reactions in an organism. C. all of the biochemical reactions in an organism that use cellular energy. D. the maintenance pH at the neutral level preferred by most microorganisms.

B. all of the energy releasing biochemical reactions in an organism.

Non-competitive inhibition occurs when: A. an inhibitor competes with substrate for an enzyme's active site. B. an inhibitor binds to an alternate site in the enzyme changing the confirmation of the active site and preventing it from binding substrate. C. an inhibitor binds to substrate and preventing it from binding the enzyme's active site. D. an inhibitor binds to the substrate-enzyme complex preventing enzyme activity.

B. an inhibitor binds to an alternate site in the enzyme changing the confirmation of the active site and preventing it from binding substrate.

Enzymes play an important role in biological chemistry because they: A. break down to release metal ions. B. increase the probability of chemical reactions. C. raise the ionic strength of a water solution. D. retain the pH at the neutral level preferred by most microorganisms

B. increase the probability of chemical reactions.

A pure culture A. is made of a clearly defined chemical medium. B. is a population of identical cells. C. contains one microbial cell. D. is sterile.

B. is a population of identical cells.

If an E. coli cell has a surface area-to-volume (S/V) ratio of 4.5, and a Pelagibacter ubique has an S/V ratio of 22, which cell will be able to exchange nutrients and wastes with the environment more efficiently?

Pelagibacter ubique, because its cells are smaller

Although the inner leaflet of the gram-negative outer membrane is composed mainly of phospholipids, the outer leaflet of the outer membrane contains A. poly-β-hydroxybutyric acids (PHB). B. lipopolysaccharides (LPS). C. pseudopeptidoglycans. D. lipoteichoic acids.

B. lipopolysaccharides (LPS).

Like all forms of life on Earth, all microbial cells perform three major types of activities: __________. A. metabolism, growth, and genetic exchange B. metabolism, growth, and evolution C. growth, genetic exchange, and evolution D. growth, differentiation, and metabolism

B. metabolism, growth, and evolution

Sucrose-Azide Agar contains yeast extract and sodium azide. Sodium azide inhibits the growth of most bacteria except Streptococci species. Sucrose-Azide Agar is an example of: A. differential media B. selective media C. synthetic media D. discriminatory media

B. selective media

In what/which domain(s) of life is/are microorganisms represented? A. Archaea B. Eukarya C. Archaea, Bacteria, and Eukarya D. Bacteria

C. Archaea, Bacteria and Eukarya

The use of the Gram stain in microbiology is important because it differentiates A. Bacteria from Archaea. B. archaeal cells with different types of metabolism. C. bacterial cells with different types of cell walls. D. prokaryotic from eukaryotic cells.

C. Bacterial cells with different types of cell walls.

The structure that confers structural strength on the cell is known as the A. cell wall. B. cytoplasmic membrane. C. ribosome. D. cytoplasm.

A. Cell wall

Penicillin is an antimicrobial drug that binds the bacterial enzyme PBP2a at its active site. This binding event inhibits the ability of PBP2a to bind its normal substrate. This is an example of: A. Competitive Inhibition B. Non-Competitive Inhibition C. Feedback Inhibition D. Negative Regulation or Repression

A. Competitive Inhibition

Which of the following is NOT TRUE about glycolysis: A. Glycolysis catabolizes glucose generating 4 ATP and 2 acetyl-CoA B. Glycolysis is utilized during fermentation. C. Glycolysis requires 2 ATP and generates 4 ATP, for net gain of 2 ATP per glucose molecule catabolized. D. The co-enzyme FAD+ is required for glycolysis.

A. Glycolysis catabolizes glucose generating 4 ATP and 2 acetyl-CoA

Twitching motility utilizes: A. Pili B. Flagella C. Lipopolysaccharide D. Glycocalyx

A. Pili

Pili are: A. Protein filaments that allow for attachment of bacteria to a surface. B. Protein filaments that rotate allowing bacteria to move. C. Proteins that help compact the nucleoid of bacteria. D. Pentacyclic chemicals that stabilize the membranes of bacteria.

A. Protein filaments that allow for attachment of bacteria to a surface.

Which one of the following is NOT utilized in both aerobic respiration and fermentation? A. Glucose B. NAD+ C. FADH2 D. ATP

C. FADH2

Which one of the following is NOT common to anaerobic respiration and fermentation? A. Pyruvate B. NAD+ C. Glycolysis D. Inorganic final electron acceptors (i.e. NO3, SO4)

C. Glycolysis

Although the existence of microorganisms was surmised long before, their discovery depended upon a technological development (the microscope) in order for scientists to __________. A make direct observations of microbes B publish their results C construct meaningful hypotheses concerning microbial activities D synthesize meaningful theories about the roles of microbes in disease

A make direct observations of microbes

You have discovered a new microorganism, but you want to know if it is a eukaryote or a prokaryote. To investigate this question you prepare a slide with a simple stain and view it with a light microscope with a 40X objective lens and 10X ocular lens. You also prepare a control slide using Saccharomyces cerevisiae (a unicellular eukaryote). You can see the cells on your control slide, but you don't see cells when you look at your unknown microorganism. What can you conclude from this experiment? A. The cells of the new unknown microorganism may be too small to see with the objective and ocular lenses you used. B. The new unknown microorganism is probably an archaeon. C. Your new unknown microorganism is probably a virus. D. The experiment failed to visualize the organism because the stain killed it.

A. The cells of the new unknown microorganism may be too small to see with the objective and ocular lenses you used.

Explain why the presence of a capsule or slime layer would benefit a bacterial cell. A. These outer layers can aid in attachment to solid surfaces. B. These outer layers can help the immune system recognize foreign organisms. C. These outer layers can prevent added virulence during a bacterial infection. D. These outer layers prevent water from entering the cell, causing rapid dehydration.

A. These outer layers can aid in attachment to solid surfaces.

What is the biological function of endospores? A. They enable organisms to endure extremes of temperature, drying, and nutrient depletion. B. Endospores can serve as reproductive structures, enable survival in harsh environments, and transport toxins. C. They are bacterial reproductive structures. D. They transport toxins.

A. They enable organisms to endure extremes of temperature, drying, and nutrient depletion.

A bacterial cell is interpreted as gram-positive when it forms purple insoluble crystal violet-iodine complexes within the cell during the Gram stain. A. True B. False

A. True

Smaller prokaryotic cells generally grow faster than larger ones due to a higher surface-area-to-volume ratio. A. True B. False

A. True

Bacteria with type IV pili A. likely exhibit twitching motility. B. possess tubular or stalk-like extensions of their cells. C. have capsules that promote dehydration. D. live in aquatic environments.

A. likely exhibit twitching motility.

In gram-positive Bacteria, the cell walls are composed mainly of thick ________ layers. A. peptidoglycan B. lipopolysaccharides (LPS) C. protein D. poly-β-hydroxybutryic acid (PHB)

A. peptidoglycan

The prokaryotic transport system that involves a substrate-binding protein, a member-integrated transporter, and an ATP-hydrolyzing protein is A. the ABC transport system B. Group Translocation C. Symport D. Simple Transport

A. the ABC transport system

Specify why is it necessary to use stains to view microorganisms. A. to increase the contrast and make the cells more visible B. to increase the resolution of the organism and make the cells more visible C. to kill the microorganism so it does not swim away D. to increase the magnification of the organism and make the cells more visible

A. to increase the contrast and make the cells more visible

Explain the differences between scanning (SEM) and transmission electron microscopy (TEM). A. With TEM the electrons scan the surface of a specimen to give a three-dimensional view, while SEM electrons show the details inside the cell in a thinly sliced specimen or a three-dimensional view if not thinly sliced. B. With SEM the electrons scan the surface of a specimen to give a three-dimensional view, while TEM electrons show the details inside the cell in a thinly sliced specimen. C. With TEM you can have a real time color image of the cell, while with SEM you only get a black and white image. D. With TEM the electrons scan the surface of a specimen to give a three-dimensional view, while SEM electrons show the detail inside the cell in a thinly sliced specimen.

B. With SEM the electrons scan the surface of a specimen to give a three-dimensional view, while TEM electrons show the details inside the cell in a thinly sliced specimen.

The Cell Wall of bacteria is made up of: A. Chains of N-Acetylglucosamine and N-Acetylmuramic acid. B. Chains of N-Acetylglucosamine and N-Acetylmuramic acid linked by peptide crosslinks. C. Chains of N-Acetylglucosamine and N-Acetylmuramic acid linked by lipid crosslinks. D. Chains of N-Acetylglucosamine and N-Acetylmuramic acid linked by carbohydrate crosslinks.

B. Chains of N-Acetylglucosamine and N-Acetylmuramic acid linked by peptide crosslinks.

Staining increases the visible contrast of cells compared with the background. Because the Gram stain results in some types of bacteria staining purple, and other types appearing pink, this is called a __________ stain. A. Counter Stain B. Differential C. Fluorescent D. Basic dye

B. Differential

Transport proteins can become saturated with solute, have high specificity for certain substances, undergo conformational (shape) changes, and are highly regulated by the cell. What other type of cellular proteins have these four general characteristics? A. Ribosomes B. Enzymes C. Flagella D. Porins

B. Enzymes

Electron microscopes have less resolving power than light microscopes. A. True B. False

B. False

Teichoic acids are commonly found in gram-negative cell walls. A. True B. False

B. False

True or false, live bacteria can be observed using a light microscope after Gram staining: A. True B. False

B. False

Which of the following is true about Gram negative bacteria? A. Gram negative bacteria stain purple when Gram stained B. Gram negative bacteria have an inner membrane and an outer membrane. C. Gram negative bacteria have a thick peptidoglycan cell wall that includes Lipotechoic acids. D. Gram negative bacteria are always bacilli and never cocci.

B. Gram negative bacteria have an inner membrane and an outer membrane.

You are given an electron micrograph of a bacterial cell. In the micrograph you can clearly see three thin layers of different densities surrounding the cell. Based on the micrograph, you can infer that this cell is ________ and would appear ________ after application of the Gram stain procedure. A. gram-positive / pink B. gram-negative / pink C. gram-negative / purple D. gram-positive / purple

B. Gram-Negative / Pink

Lipopolysaccharide is present in: A. Gram-positive bacteria B. Gram-negative bacteria C. Eukaryotic cells D. Viruses

B. Gram-negative bacteria

Which of the following statements is FALSE? A.Fimbriae are generally shorter and more numerous than flagella. B. Pili serve as receptors and facilitate genetic exchange between prokaryotic cells. C. Fibriae are usually shorter than flagella and enable cells to adhere to surfaces, whereas pili are involved in genetic exchange. D. Fimbriae enable cells to stick to surfaces.

B. Pili serve as receptors and facilitate genetic exchange between prokaryotic cells.

Flagella are: A. Protein filaments that allow for attachment of bacteria to a surface. B. Protein filaments that rotate allowing bacteria to move. C. Proteins that help compact the nucleoid of bacteria. D. Pentacyclic chemicals that stabilize the membranes of bacteria.

B. Protein filaments that rotate allowing bacteria to move.

How did the rough S. pneumoniae in Griffith's experiment acquire the ability to make capsule and become pathogenic (able to cause disease)? A. Rough bacteria acquired capsule directly from dead smooth bacteria. B. Rough bacteria acquired DNA from dead smooth bacteria that contained the genes required for bacteria to produce capsule. C. Rough bacteria acquired the enzymes required to make capsule from the dead smooth bacteria.

B. Rough bacteria acquired DNA from dead smooth bacteria that contained the genes required for bacteria to produce capsule.

Explain the germ theory of disease. A. All microorganisms can cause disease. B. Some microorganisms can cause disease. C. Only pure cultures of microorganisms cause disease. D. Something in the air caused healthy people to become sick.

B. Some microorganisms can cause disease.

The germ theory of disease refers to: A. The theory that all human diseases are caused by microorganisms that have gained access to the human body. B. The theory that some human diseases are caused by microorganisms that have gained access to the human body. C. The theory that all human disease is transferred from person to person via microorganisms. D. The theory that all human disease is the result of microorganisms already living inside or on a human body.

B. The theory that some human diseases are caused by microorganisms that have gained access to the human body.

An apoenzyme is: A. a functional enzyme-co-factor complex B. a non-functional enzyme that lacks it co-factor C. a functional enzyme that does not require a co-factor D. a non-functional enzyme bound to an inhibitor.

B. a non-functional enzyme that lacks it co-factor

Which of the following is NOT TRUE about Gram negative bacteria? A. Gram negative bacteria stain pink when Gram stained B. Gram negative bacteria have an inner membrane and an outer membrane. C. Gram negative bacteria have a thick peptidoglycan cell wall that includes Lipotechoic acids. D. Gram negative bacteria have outer membrane composed of both phospholipid and lipopolysaccharide.

C. Gram negative bacteria have a thick peptidoglycan cell wall that includes Lipotechoic acids.

Which of the following statements is FALSE? A. Microbial cells carry out their life processes of growth independently. B. Microbial cells exist as single cells. C. Microbial cells include both bacteria and viruses. D. Microbial cells exclude the cells of plants and animals.

C. Microbial cells include both bacteria and viruses.

A microbial cell's membrane is considered ________, because its internal constituents are maintained within the cell. However, it also imports and exports other molecules in response to its environment. A. rigid B. differential C. semipermeable D. microselective

C. Semipermeable

The presence of which of the components listed below would allow you to distinguish between a gram-positive or gram-negative cell wall? A. N-acetylglucosamine - gram-negative B. teiochic acids -- gram-negative C. teichoic acids -- gram-positive D. N-acetylmuramic acid - gram-positive

C. Teichoic acids -- gram-positive

Lipotechoic acid (LTA) is a polysaccharide found in: A. The outer membrane of Gram Negative Bacteria B. The inner membrane of Gram Negative Bacteria C. The cell wall of Gram Positive Bacteria D. The cell wall of all bacteria.

C. The cell wall of Gram Positive Bacteria

Which of the following is true about the citric acid cycle: A. The citric acid cycle catabolizes glucose generating 4 ATP and 2 acetyl-CoA B. The citric acid utilizes 2 acetyl-CoA molecules to produce 3 NADH and 1 FADH2 . C. The citric acid utilizes 2 acetyl-CoA molecules to produce 6 NADH and 2 FADH2 . D. The citric acid cycle utilizes 10 NADH and 2 FADH2 to generate 28 ATP.

C. The citric acid utilizes 2 acetyl-CoA molecules to produce 6 NADH and 2 FADH2

.__________ are not cellular and cannot be grown in pure culture. A. Fungi B. Bacteria C. Viruses D. Amoeba

C. Viruses

Which of the following is/are characteristic of ALL cellular organisms? A. motility B. communication C. evolution D. communication, evolution, and motility

C. evolution

Compared to Eukaryotes, Bacteria and Archaea have ________ surface-to-volume ratios, causing ________ nutrient exchange and growth rates. A. higher / lower B. lower / lower C. higher / higher D. lower / higher

C. higher / higher

Archaea and Bacteria are unified as prokaryotes in lacking ________ which Eukarya contain, such as golgi. A. membranes B. membrane-enclosed organelles C. nuclei and membrane-enclosed organelles D. nuclei

C. nuclei and membrane-enclosed organelles

Nutrient transport requires energy because the nutrients must be transported into the cell against a concentration gradient. The energy required for nutrient transport is supplied by A. ATP. B. the proton motive force. C. phosphoenol pyruvate. D. ATP, the proton motive force, or phosphoenol pyruvate.

D. ATP, the proton motive force, or phosphoenol pyruvate.

Which is/are a function(s) of the cytoplasmic membrane in prokaryotes? A. It is a major site of energy conservation. B. It is an anchor for many proteins involved in bioenergetic reactions and transport. C. It functions as a permeability barrier. D. It serves as a permeability barrier, a docking station for proteins involved in bioenergetics reactions and transport, and a site for energy conservation.

D. It serves as a permeability barrier, a docking station for proteins involved in bioenergetics reactions and transport, and a site for energy conservation.

Which of the following is NOT utilized during Anaerobic Respiration: A. NADH B. FADH2 C. ATP D. O2

D. O2

Spherical bacteria arranged in chains are referred to as: A. Diplococci B. Streptobacilli C. Staphylococci D. Streptococci

D. Streptococci

Which of the following is NOT true about endospores: A. Endospores are metabolically dormant forms of bacteria. B. Not all bacteria can make endospores. C. Endospores can be destroyed by autoclaving. D. The process of forming an endospore is faster than the normal process of cell growth and division.

D. The process of forming an endospore is faster than the normal process of cell growth and division.

Prokaryotes exhibit these common features found in all living things. Identify the exception. A. They use DNA as the hereditary material. B. They use complex biochemical patterns of growth and energy conversions. C. They adapt from one generation to the next. D. They do not respond to stimuli.

D. They do not respond to stimuli.

The cytoplasmic membrane could best be described as A. an impermeable barrier. B. a rigid structure that protects the cell. C. a passive conduit for intracellular transport. D. a highly selective permeability barrier.

D. a highly selective permeability barrier.

The terms "run" and "tumble" are generally associated with A. nutrient transport. B. clustering of certain rod-shaped bacteria. C. eukaryotic cells. D. chemotaxis.

D. chemotaxis.

The lipopolysaccharide (LPS) layer is found ONLY in the cell walls of A. Eukarya. B. Archaea. C. gram-positive Bacteria. D. gram-negative Bacteria

D. gram-negative Bacteria

Regarding early life on Earth, A. microbial life existed long before animals but has been around for about the same amount of time as plants. B. microbial life, plant life, and animal life all appeared at about the same time. C. it is impossible to determine which type of life first appeared. D. microbial life existed for billions of years before plant and animal life.

D. microbial life existed for billions of years before plant and animal life.

Arrange Koch's postulates in the correct order. A. pathogen present in all cases of disease; pathogen isolated in pure culture; pathogen re-isolated; pathogen able to infect healthy host B. pathogen present in all cases of disease; pathogen able to infect healthy host; pathogen isolated in pure culture; pathogen re-isolated C. pathogen isolated in pure culture; pathogen present in all cases of disease; pathogen re-isolated; pathogen able to infect healthy host D. pathogen present in all cases of disease; pathogen isolated in pure culture; pathogen able to infect healthy host; pathogen re-isolated

D. pathogen present in all cases of disease; pathogen isolated in pure culture; pathogen able to infect healthy host; pathogen re-isolated

A student observed a stained specimen of bacteria using bright-field microscopy. At 100x magnification, there appeared to be only one cell in the field of view, but at 1000x it was clear that there were two cells close together. The ability to distinguish these two cells as separate entities is called __________. A. magnification B. cell division C. wavelength D. resolution

D. resolution

Chemoheterotrophs: A. use light as their energy source and organic compounds as their source of carbon. B. use inorganic compounds as their energy source and synthesize their own foods from simple carbon sources like carbon dioxide. C. use light as their energy source and synthesize their own foods from simple carbon sources like carbon dioxide. D. use organic compounds both for energy and carbon sources

D. use organic compounds both for energy and carbon sources

Bacteria stain as gram-positive or gram-negative because of differences in the cell A. nucleus. B. cytoplasm. C. chromosome. D. wall.

D. wall.

According to our present understanding, each of the three major domains has what is known as its own universal ancestor. a. True b. False

b. False