Brock Biology Of Microorganisms, 14th Edition Test Bank

Brock Biology of Microorganisms, 14e (Madigan et al.) Chapter 2 Microbial Cell Structure and Function Multiple Choice Questions 1) An organism of the genus Staphylococcus is ________, while an organism of the genus Spirochaeta is ________. A) spherical / rod shaped B) rod shaped / coiled C) spherical / coiled D) coiled / spherical Answer: C Bloom’s Taxonomy: Comprehension Chapter Section: 2.5 2) Bacteria with type IV pili A) possess tubular or stalk-like extensions of their cells. B) likely exhibit twitching motility. C) have capsules that promote dehydration. D) live in aquatic environments. Answer: B Bloom’s Taxonomy: Comprehension Chapter Section: 2.13 3) The terms “run” and “tumble” are generally associated with A) eukaryotic cells. B) nutrient transport. C) chemotaxis. D) clustering of certain rod-shaped bacteria. Answer: C Bloom’s Taxonomy: Knowledge Chapter Section: 2.17 4) The morphology of a cell influences its A) motility. B) metabolism. C) surface-to-volume ratio. D) motility and surface-to-volume ratio. Answer: D Bloom’s Taxonomy: Comprehension Chapter Section: 2.5 5) Compared to Eukaryotes, Bacteria and Archaea have ________ surface-to-volume ratios, causing ________ nutrient exchange and growth rates. A) lower / lower B) lower / higher C) higher / lower D) higher / higher Answer: D Bloom’s Taxonomy: Application Chapter Section: 2.6 6) The cytoplasmic membrane could best be described as A) an impermeable barrier. B) a passive conduit for intracellular transport. C) a highly selective permeability barrier. D) a rigid structure that protects the cell. Answer: C Bloom’s Taxonomy: Comprehension Chapter Section: 2.9 7) The use of the Gram stain in microbiology is important because it differentiates A) Bacteria from Archaea. B) prokaryotic from eukaryotic cells. C) bacterial cells with different types of cell walls. D) archaeal cells with different types of metabolism. Answer: C Bloom’s Taxonomy: Comprehension Chapter Section: 2.7 8) Some archaea have unique phospholipids in their cytoplasmic membrane that A) form a monolayer due to the presence of diglycerol tetraethers. B) form a bilayer due to the presence of sterols. C) form a stable ring structure due to the presence of crenarchaeol. D) form a bilayer due to the presence of phosphatidylethanolamine. Answer: A Bloom’s Taxonomy: Knowledge Chapter Section: 2.7 9) Carrier-mediated transport is necessary when A) diffusion will not allow adequate amounts of a substance to enter the cell. B) movement into the cell is against a concentration gradient. C) the level of nutrients in nature is very low. D) nutrient concentration is very low in the environment, is higher inside of the cell, or diffusion is not possible. Answer: D Bloom’s Taxonomy: Comprehension Chapter Section: 2.6 10) 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. Answer: A Bloom’s Taxonomy: Comprehension Chapter Section: 2.9 11) 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 experiment failed to visualize the organism because the stain killed it. B) Your new unknown microorganism is probably a virus. C) The cells of the new unknown microorganism may be too small to see with the objective and ocular lenses you used. D) The new unknown microorganism is probably an archaeon. Answer: C Bloom’s Taxonomy: Evaluation Chapter Section: 2.11 12) Bacteria stain as gram-positive or gram-negative because of differences in the cell A) wall. B) cytoplasm. C) nucleus. D) chromosome. Answer: A Bloom’s Taxonomy: Knowledge Chapter Section: 2.10 13) 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 / purple B) gram-negative / pink C) gram-positive / pink D) gram-negative / purple Answer: B Bloom’s Taxonomy: Analysis Chapter Section: 2.10 14) In gram-positive Bacteria, the cell walls are composed mainly of thick ________ layers. A) protein B) poly-β-hydroxybutryic acid (PHB) C) lipopolysaccharides (LPS) D) peptidoglycan Answer: D Bloom’s Taxonomy: Knowledge Chapter Section: 2.10 15) You have discovered a new coccoid-shaped microorganism with no nucleus, a rigid cell wall, and a diameter of 2 µm. Chemical tests reveal that its cell wall does NOT contain peptidoglycan. The new microorganism is A) most likely a bacterium. B) most likely a eukaryote. C) most likely an archaeon. D) either a bacterium or an archaeon. Answer: C Bloom’s Taxonomy: Analysis Chapter Section: 2.11 16) The lipopolysaccharide (LPS) layer is found ONLY in the cell walls of A) gram-positive Bacteria. B) gram-negative Bacteria. C) Archaea. D) Eukarya. Answer: B Bloom’s Taxonomy: Knowledge Chapter Section: 2.11 17) An endotoxin is A) the toxic portion of the LPS. B) a toxin produced within archaeal cells. C) a toxin known for its primary attack on the epidermis of mammals. D) a toxin produced in the periplasm of most bacteria. Answer: A Bloom’s Taxonomy: Knowledge Chapter Section: 2.11 18) Hydrolytic enzymes function in the A) initial degradation of nutrients. B) transport of substrates within the cell. C) chemotactic response, particularly in gram-negative Bacteria. D) regeneration of the periplasm. Answer: A Bloom’s Taxonomy: Comprehension Chapter Section: 2.9 19) Using phase contrast microscopy on a wet mount of live cells, you observe motile bacilli moving rapidly and randomly through the field of view, changing directions after a brief tumble and taking off in a different direction. These cells are exhibiting ________ motility. A) twitching B) swimming C) gliding D) twitching or gliding Answer: B Bloom’s Taxonomy: Comprehension Chapter Section: 2.18 20) Which of the following statements is FALSE? A) A flagellar protein subunit is flagellin. B) In flagellar motion, the basal body acts as a motor. C) Flagellar rotation generates ATP. D) The hook is the wider region at the base of the flagellum. Answer: C Bloom’s Taxonomy: Knowledge Chapter Section: 2.17 21) Which of the following statements is TRUE? A) Fimbriae are generally shorter and more numerous than flagella. B) Fimbriae enable cells to stick to surfaces. C) Pili serve as receptors and facilitate genetic exchange between prokaryotic cells. D) Fibriae are usually shorter than flagella and enable cells to adhere to surfaces, whereas pili are involved in genetic exchange. Answer: D Bloom’s Taxonomy: Knowledge Chapter Section: 2.13 22) Cellular inclusions in prokaryotic cells serve to A) store energy rich compounds. B) protect DNA. C) position cells in the appropriate environment for survival. D) store energy rich compounds and position cells in the appropriate environment for survival. Answer: D Bloom’s Taxonomy: Comprehension Chapter Section: 2.14 23) A major function of prokaryotic gas vesicles is to A) confer buoyancy on cells by decreasing their density. B) serve as a reservoir for oxygen and carbon dioxide. C) keep the cell’s organelles separated during flagellar motion. D) store oxygen for aerobic growth when oxygen becomes depleted in the environment. Answer: A Bloom’s Taxonomy: Knowledge Chapter Section: 2.15 24) The membrane of a gas vesicle is composed of A) various phospholipids. B) proteins. C) carbohydrates. D) both glycoproteins and phospholipids. Answer: B Bloom’s Taxonomy: Knowledge Chapter Section: 2.15 25) What is the biological function of endospores? A) They are bacterial reproductive structures. B) They enable organisms to endure extremes of temperature, drying, and nutrient depletion. C) They transport toxins. D) Endospores can serve as reproductive structures, enable survival in harsh environments, and transport toxins. Answer: B Bloom’s Taxonomy: Comprehension Chapter Section: 2.16 26) The lipids in the cytoplasmic membrane of Bacteria and ________ contain ester linkages, while the cytoplasmic membrane of ________ contain ether linkages. A) Archaea / Eukarya B) Archaea / fungi C) Eukarya / prokaryotes D) Eukarya / Archaea Answer: B Bloom’s Taxonomy: Knowledge Chapter Section: 2.7 27) Aquaporins are A) water transport proteins. B) molecules that prevent water from crossing a membrane. C) enzymes involved in the generation of water within cells. D) cations bound to water molecules. Answer: A Bloom’s Taxonomy: Comprehension Chapter Section: 2.8 28) Electron microscopy has greater ________ than light microscopy, because the wavelengths of visible light are much larger than the wavelengths of electrons. A) contrast B) magnification C) resolution D) penetration Answer: C Bloom’s Taxonomy: Knowledge Chapter Section: 2.4 29) The prokaryotic transport system that involves a substrate-binding protein, a membraneintegrated transporter, and an ATP-hydrolyzing protein is A) the ABC transport system. B) group translocation. C) symport. D) simple transport. Answer: A Bloom’s Taxonomy: Knowledge Chapter Section: 2.9 30) ________ are charged molecules that are partially responsible for the ________ charge of the gram-positive bacterial cell surface. A) Diaminopimelic acids / positive B) Teichoic acids / negative C) Phospholipids / negative D) Peptide interbridges / neutral Answer: B Bloom’s Taxonomy: Comprehension Chapter Section: 2.10 31) Although the inner leaflet of the gram-negative outer membrane is composed mainly of phospholipids, the outer leaflet of the outer membrane contains A) pseudopeptidoglycans. B) lipoteichoic acids. C) poly-β-hydroxybutyric acids (PHB). D) lipopolysaccharides (LPS). Answer: D Bloom’s Taxonomy: Knowledge Chapter Section: 2.11 32) One of the many types of proteins found in the cytoplasmic membrane is involved in the chemotactic response and is called a A) hydrolytic enzyme. B) chemoreceptor. C) binding protein. D) porin. Answer: B Bloom’s Taxonomy: Knowledge Chapter Section: 2.19 33) When does endospore formation commence? A) when bacterial growth ceases due to limitation of an essential nutrient B) when the bacterium is undergoing binary fission C) when bacteria are dividing exponentially D) following bacterial death Answer: A Bloom’s Taxonomy: Comprehension Chapter Section: 2.16 34) Which is/are a function(s) of the cytoplasmic membrane in prokaryotes? A) It functions as a permeability barrier. B) It is an anchor for many proteins involved in bioenergetic reactions and transport. C) It is a major site of 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. Answer: D Bloom’s Taxonomy: Comprehension Chapter Section: 2.8 35) All eukaryotes contain A) a membrane-enclosed nucleus. B) mitochondria. C) hydrogenosomes. D) a nucleus, mitochondria, and hydrogenosomes. Answer: A Bloom’s Taxonomy: Knowledge Chapter Section: 2.21 36) Mitochondria and hydrogenosomes are similar in that they both A) are the site of energy production in eukaryotic cells. B) evolved via endosymbiosis of bacterial cells. C) are the site of aerobic respiration. D) evolved via endosymbiosis and are sites for aerobic respiration and energy production. Answer: A Bloom’s Taxonomy: Comprehension Chapter Section: 2.21 37) Membrane-enclosed organelles, such as nuclei, lysosomes, endoplasmic reticulum, mitochondria, and chloroplasts, A) form specialized compartments within eukaryotic cells for specific functions to occur. B) increase the structural complexity of eukaryotic cells. C) help large eukaryotic cells overcome the limitations of diffusion imposed by their large cell size. D) increase structural complexity, help eukaryotes overcome diffusion limitation due to their size, and form specialized environments for specific functions to occur. Answer: A Bloom’s Taxonomy: Synthesis Chapter Section: 2.21 38) The Golgi complex functions to A) modify and secrete proteins to the external environment. B) sort proteins used within the cell. C) both modify and sort proteins into those destined for secretion and those that function in membrane structures. D) synthesize proteins. Answer: C Bloom’s Taxonomy: Knowledge Chapter Section: 2.22 39) The membrane-enclosed compartments that contain digestive enzymes in eukaryotic cells are called A) cristae. B) mitosomes. C) lysosomes. D) stromas. Answer: C Bloom’s Taxonomy: Knowledge Chapter Section: 2.22 40) Where within a eukaryotic cell is ribosomal RNA (rRNA) synthesized? A) cytoplasm B) lysosome C) mitochondrion D) nucleolus Answer: D Bloom’s Taxonomy: Knowledge Chapter Section: 2.20 41) The energy source derived from the charge separation across the cytoplasmic membrane is referred to as A) the proton motive force. B) carbohydrate charging. C) adenosine triphosphate. D) the voltage source. Answer: A Bloom’s Taxonomy: Comprehension Chapter Section: 2.16 42) Based on the table of attributes given below, which of the following statements are FALSE about the two organisms? Characteristic Endospore formation Capsule Type IV pili Flagella Morphology Bacterium A yes no yes no bacillus Bacterium B no yes no no bacillus A) Bacterium A is more resistant to heat and ultraviolet light. B) Bacterium B likely forms a slime layer better than Bacterium A. C) Bacterium B is likely to exhibit motility. D) Both bacteria may attach to surfaces. Answer: C Bloom’s Taxonomy: Analysis Chapter Section: 2.18 43) Small acid-soluble proteins (SASPs) protect DNA from ultraviolet light and are found in high numbers within A) gram-positive Bacteria. B) endospores. C) inclusion bodies. D) gram-negative Bacteria. Answer: B Bloom’s Taxonomy: Comprehension Chapter Section: 2.16 44) The peptide interbridge crosslinking between peptidoglycan layers is found ONLY in the cell walls of A) Archaea. B) Eukarya. C) gram-positive Bacteria. D) gram-negative Bacteria. Answer: C Bloom’s Taxonomy: Knowledge Chapter Section: 2.10 45) Type IV pili are involved in A) attachment of cells to surfaces. B) twitching motility. C) pathogenesis. D) attachment to surfaces, twitching motility, and pathogenesis. Answer: D Bloom’s Taxonomy: Knowledge Chapter Section: 2.18 46) Eukaryotes have ________ in their cytoplasmic membranes, which serve to strengthen and stabilize the membrane and make it less flexible. Many bacteria have similar molecules, known as ________, in their cytoplasmic membranes that have a similar role. A) ether bonds / ester bonds B) lipids / phospholipids C) sterols / hopanoids D) phospholipids / lipopolysaccharides Answer: C Bloom’s Taxonomy: Comprehension Chapter Section: 2.7 47) The rigid layer that is present in the cell walls of Bacteria that is primarily responsible for the strength of the wall is known as A) pseudomurein. B) S-layer. C) cellulose. D) peptidoglycan. Answer: D Bloom’s Taxonomy: Application Chapter Section: 2.10 48) Some of the intestinal symptoms elicited by pathogens such as Salmonella, Shigella, and Escherichia are due to the presence of A) pseudomurein. B) S-layers. C) lipopolysaccharides. D) peptidoglycan. Answer: C Bloom’s Taxonomy: Knowledge Chapter Section: 2.11 49) Which of the following types of microscopy can be used with live cells? A) phase-contrast microscopy B) transmission electron microscopy C) bright-field microscopy D) scanning electron microscopy Answer: A Bloom’s Taxonomy: Knowledge Chapter Section: 2.4 50) Which of the following types of microscopy could be used to visualize the layers of the cell membrane and the cell wall? A) phase-contrast microscopy B) transmission electron microscopy C) bright-field microscopy D) confocal microscopy Answer: B Bloom’s Taxonomy: Knowledge Chapter Section: 2.4 51) Using bright-field microscopy to look at a slide prepared with a basic dye you observe cells under 400X magnification with a clear inner compartment within the cell. The cell is most likely a(n) A) prokaryote. B) bacterium. C) archaeon. D) eukaryote. Answer: D Bloom’s Taxonomy: Analysis Chapter Section: 2.21 True/False Questions 1) In general, most cell inclusions function as energy reserves or as a reservoir of structural building blocks. Answer: TRUE Bloom’s Taxonomy: Comprehension Chapter Section: 2.14 2) Smaller prokaryotic cells generally grow faster than larger ones due to a higher surface-areato-volume ratio. Answer: TRUE Bloom’s Taxonomy: Comprehension Chapter Section: 2.6 3) In general, lipids in archaeal cytoplasmic membranes lack true fatty acids. Answer: TRUE Bloom’s Taxonomy: Comprehension Chapter Section: 2.7 4) Some membrane proteins are involved in bioenergetic reactions, while others are involved in membrane transport. Answer: TRUE Bloom’s Taxonomy: Comprehension Chapter Section: 2.9 5) Both hydrophilic and charged molecules readily diffuse through the cytoplasmic membrane. Answer: FALSE Bloom’s Taxonomy: Comprehension Chapter Section: 2.9 6) ATP-binding cassette transport systems have high substrate affinity and thus help microorganisms survive in low nutrient environments. Answer: TRUE Bloom’s Taxonomy: Comprehension Chapter Section: 2.9 7) Teichoic acids are commonly found in gram-negative cell walls. Answer: FALSE Bloom’s Taxonomy: Knowledge Chapter Section: 2.10 8) Despite the invariance of the peptidoglycan backbone’s structure, there are more than 100 different types of peptidoglycan. Answer: TRUE Bloom’s Taxonomy: Comprehension Chapter Section: 2.10 9) Lysozyme is an enzyme that can ultimately lyse and kill eukaryotic cells by breaking β-1,4glycosidic bonds in peptidoglycan. Answer: FALSE Bloom’s Taxonomy: Application Chapter Section: 2.10 10) Porins are channels in the outer membranes of gram-positive Bacteria. Answer: FALSE Bloom’s Taxonomy: Comprehension Chapter Section: 2.11 11) A bacterial cell is interpreted as gram-positive when it forms purple insoluble crystal violetiodine complexes within the cell during the Gram stain. Answer: TRUE Bloom’s Taxonomy: Comprehension Chapter Section: 2.10 12) In general, swimming is performed with flagella, whereas gliding uses other cellular components such as pili. Answer: TRUE Bloom’s Taxonomy: Comprehension Chapter Section: 2.18 13) Chemotaxis is a sensory response affecting the rotational direction of the flagellar motor. Answer: TRUE Bloom’s Taxonomy: Comprehension Chapter Section: 2.17 14) Photoreceptors are analogous to chemoreceptors in that they are both proteinaceous sensors. Answer: TRUE Bloom’s Taxonomy: Knowledge Chapter Section: 2.19 15) Pathogenic bacteria that contain S-layers are protected against host defense mechanisms. Answer: FALSE Bloom’s Taxonomy: Comprehension Chapter Section: 2.12 16) Poly-β-hydroxybutyric acid (PHB) is a carbon- and energy-storing polymer. Answer: TRUE Bloom’s Taxonomy: Knowledge Chapter Section: 2.14 17) Mitochondria and chloroplasts have their own DNA and ribosomes, which supports the endosymbiosis hypothesis. Answer: TRUE Bloom’s Taxonomy: Comprehension Chapter Section: 2.21 18) Macromolecules resulting from lysosomal digestion are used in cellular biosynthesis and energy generation. Answer: TRUE Bloom’s Taxonomy: Knowledge Chapter Section: 2.22 19) Electron microscopes have less resolving power than light microscopes. Answer: FALSE Bloom’s Taxonomy: Comprehension Chapter Section: 2.4 Essay Questions 1) Why is energy required for nutrient transport? Give an example of a system that transports nutrients and describe what source of energy is used to move the nutrients into the cell. Answer: Energy is required for nutrient transport because nutrient concentration outside of the cell is lower than the nutrient concentrations inside the cell, thus nutrient transport moves solutes against a concentration gradient and requires energy. There are three examples in the text. The student could describe any one of them. They are (i) Simple transporter such as lac permease. Each nutrient molecule is cotransported into the cell with a H+ ion, thus the proton motive force provides the energy to transport nutrients. (ii) Group translocation such as sugar phosphotransferases. Each nutrient molecule is modified during the transport process. The modification, in this case, phosphorylation, releases energy, thus the energy source is an energyrich compound such as phosphoenol pyruvate or some other phosphorylated compound. (iii) ABC transporters. In this example specific binding proteins bind to nutrient molecules with high affinity. Movement of the nutrient into the cell is coupled to ATP hydrolysis, thus ATP is the source of energy for transporting nutrients. Bloom’s Taxonomy: Comprehension Chapter Section: 2.9 2) Describe the makeup of the phospholipid bilayer. Include molecular orientation and proteins as well. Answer: The fatty acid components of the lipids in the cytoplasmic membrane are oriented toward each other, whereas the glycerol-phosphates point out toward the cytoplasm and external environment. Proteins can span the entire membrane (both layers) or be embedded in the phospholipids on either side of the membrane. Bloom’s Taxonomy: Comprehension Chapter Section: 2.7 3) Compare and contrast the chemical composition and structure of the cytoplasmic membranes found in Bacteria and Archaea. What is the advantage of the archaeal membranes in relationship to the types of environments many archaea inhabit? Answer: Bacterial cytoplasmic membranes contain fatty acids with ester linkages that always form a phospholipid bilayer that is highly fluid. Archaeal cytoplasmic membranes contain glycerol ethers that are either diether or tetraethers. Glycerol diether molecules form a bilayer membrane and glycerol tetraether form a monolayer membrane. Both the ether linkages and the monolayer structure are more rigid than the bilayer ester-linked fatty acids and are more stable at high temperatures and pressures. Archaea tend to inhabit more extreme environments in terms of temperature, pressure, and salt, thus the more stable membrane components allow archaea to survive under these conditions. Bloom’s Taxonomy: Synthesis Chapter Section: 2.8 4) Explain the differences between uniporters, symporters, and antiporters. 8) What type of microscope would you use to visualize the internal structures of a chloroplast? Support your conclusion with evidence based on the size of the structures you want to see and the resolution and magnification power of different types of microscopes. Answer: Transmission electron microscopy would be necessary to visualize the internal structures of a chloroplast. Chloroplasts are less than 5 μm in diameter and the internal membranes are only 10 nm thick. Light microscopes only have a resolution of 200 nm, thus any structure less than 200 nm will not be visible. Individual chloroplasts could be seen with a light microscope, but not the structures inside. Scanning electron microscopy can only see external features because electrons cannot penetrate the cell, thus the cell must be sectioned and prepared for transmission electron microscopy to see the inside of the chloroplasts. Bloom’s Taxonomy: Evaluation Chapter Section: 2.4 9) You have discovered a new bacterial strain that causes urinary tract infections. Closely related bacterial species cannot cause infections. You compare the strains and find that your new strain has structures composed of protein external to its cell wall. What structures might your new strain have that the other strains do not? Why? Answer: Pili or fimbrae are the most likely structures that are found in the new pathogenic strain but missing in the nonpathogenic strains. Both pili and fimbrae aid in attachment of cells to surfaces and tissues. Attachment is important for pathogenesis. In addition, some pili are involved in twitching motility, which can help cells invade the body. (Other answers such as the capsule would only be partly correct, since the capsule is not made of protein. Flagella could also be an acceptable answer if they logically connect swimming motility to pathogenesis.) Bloom’s Taxonomy: Evaluation Chapter Section: 2.13 10) Construct a chart to show at least five major differences between the cytoplasmic membrane and cell wall of bacteria and archaea. What are the implications of these differences? Answer: Answers could include the following: the abundance or presence of amino acid stereoisomers, polysaccharides, pseudomurein and S-layers, action of lysozyme and penicillin, and type of glycosidic bonds. Bloom’s Taxonomy: Synthesis Chapter Section: 2.12 11) Explain why prokaryotes tend to survive and adapt more rapidly to extreme and dynamic environmental conditions than eukaryotes. Answer: Answers will vary, but should reflect an understanding of how the higher surface-tovolume ratio influences the growth rate and total accumulation of mutations in prokaryotes. Another feature that increases mutation rate is the haploid nature of prokaryotes. Lastly, answers could mention that the rigid cell walls and various changes in the cytoplasmic membrane make it easier for prokaryotes to survive in unusual and extreme environments. Bloom’s Taxonomy: Synthesis Chapter Section: 2.6 12) Compare and contrast the location and activities of periplasm-binding proteins of ABC transport systems in gram-negative and gram-positive Bacteria. Answer: Answers will vary, but the main difference is gram negatives have many transport proteins within the cell’s periplasmic space and gram positives (which lack a periplasm) have them anchored to the external surface of the cell; overall ATP-hydrolysis transportation is the same. Bloom’s Taxonomy: Comprehension Chapter Section: 2.6 13) Elaborate on why discovering endospores was important to microbiology. Answer: Endospores allow bacteria to survive boiling water, UV light, and extreme dessication, as well as allowing them to be in a dormant state for very long periods of time. Two possible themes could be how the discovery of endospores changed sterilization procedures for food and surgical instruments, as well as a change in our view of how bacteria can survive, such as surviving in space and surviving 1,000s of years in a dormant state. Bloom’s Taxonomy: Evaluation Chapter Section: 2.16 14) Predict what would happen to a motile bacterium undergoing chemotaxis if the Mot proteins suddenly ceased to function. Answer: The function of Mot proteins should be described producing the rotation of the flagella. This would probably allow flagella to form, but they would not be able to rotate. The bacterium would not be able to move, but the flagella would still look normal. Bloom’s Taxonomy: Evaluation Chapter Section: 2.19 15) Explain why a eukaryotic cell needs membrane-enclosed lysosomes and peroxisomes. Answer: The structures both contain high concentrations of enzymes that serve as a localized region to perform specific reactions. Enclosed membranes provide a barrier to maintain conditions within the lysosomes and peroxisomes that are unlike those in the cytoplasm, which is important because environmental conditions for these processes to be optimal are often different than the conditions in the cytoplasm. Bloom’s Taxonomy: Synthesis Chapter Section: 2.22