micro lecture 2 (2nd part)

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micro lecture 2 (2nd part)
2014-09-24 10:58:44

part two
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  1. Which of the following is NOT a characteristic of a eukaryotic cell?
    can undergo translation and transcription simultaneously
  2. A bacterial cell possesses a glycocalyx. Which of the following is FALSE?
    It will be engulfed more quickly by defensive cells of the host.
  3. A bacterial cell stains positive with the acid-fast stain. Which of the following is FALSE?
    It has a cell wall that contains endotoxin.
  4. A bacterial cell is placed in distilled water. Which of the following will happen?
    The cell will gain water.
  5. PHB is NOT associated with which of the following words?
  6. The hami of some archaea are used for which of the following processes?
  7. The archaea are similar to bacteria in all of the following aspects EXCEPT __________.
    their ribosomal proteins
  8. The process of bringing a solid substance into the cell is known as __________.
  9. Which of the following is NOT a membranous organelle within a eukaryotic cell?
  10. If a eukaryotic cell suffers damage to its mitochondria, which of the following processes of life will be most immediately affected?
    energy production
  11. What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass?
    They have both hydrophilic and hydrophobic regions.
  12. Integral proteins are mostly involved in
    transport function.
  13. How does water enter and exit a cell?
    By simple diffusion or by use of an integral transport protein
  14. A glycoprotein
    is a type of peripheral protein above that can be used as a receptor or in enzymatic functions.
  15. What structural part of a bacterial flagellum is composed of flagellin?
  16. How are Gram-positive and Gram-negative flagella different?
    A Gram-positive flagellum has only two rings in its basal body; Gram-negatives each have four.
  17. The rings
    anchor the flagellum to the cell membrane.
  18. The basal body is comprised of which structural component(s) of flagella?
    Rod and Rings
  19. Pathogenic bacteria
    can be identified and classified by differences in their flagellar proteins.
  20. Which of the following scenarios is an example of bacterial motility?
    A bacterium moving towards a food source
  21. Axial filaments are found on
  22. How do axial filaments differ from regular bacterial flagella?
    The axial filament is located between the cell membrane and the outer membrane.
  23. What is the advantage to spirochetes of the corkscrew movement provided by axial filaments?
    It allows the cells to move more easily through viscous human tissues and fluids, such as mucus.
  24. Axial filaments are composed of
  25. Which of the following statements about bacterial flagella is true?
    Flagella can rotate 360 degrees.
  26. taxis is
    movement towards or away from a stimulus.
  27. Which of the following terms refers to a bacterium moving towards a light source?
    Positive phototaxis
  28. As a bacterium approaches a food source, one would expect
    runs to become more frequent.
  29. Why are receptors on the cell surface necessary for bacterial movement?
    The receptors sense the stimulus and send signals to the flagella.
  30. Tumbles occur when
    the flagella rotate clockwise.
  31. Which of the following types of bacterial cells would have only a single flagellum?
  32. Peritrichous bacteria make a run when
    the flagella turn counterclockwise and become bundled.
  33. Which of the following types of bacterial cells would have flagella located at only one end of the cell?
    Lophotrichous and monotrichous
  34. Which of the following molecules would be blocked by a cell membrane?
  35. Hydrophobic molecules would enter a cell
    through integral transport proteins.
  36. What is a hallmark of passive transport across cell membranes?
    It occurs along an electrochemical gradient, and may involve the use of transport proteins.
  37. A positively charged sodium ion
    would require the use of integral protein channels to pass through a cell membrane.
  38. Which of the following statements regarding active transport is false?
    It powers the diffusion of water across the cell membrane.
  39. Which of the following molecules is shared by both Gram-positive and Gram-negative organisms?
    N-acetylmuramic acid
  40. Amoxicillin is an antibiotic that inhibits the formation of peptide cross-links. Amoxicillin, therefore, would most likely inhibit the growth of __________.
    both Gram-positive and Gram-negative organisms
  41. Porins are present in ______________bacteria because, in these organisms, molecules entering the cell must pass through an extra layer of ___________.
    Gram-negative; membrane
  42. Why is no energy required in passive transport?
    The concentration gradient drives the movement.
  43. Once equilibrium is reached,
    molecules move, but there is no net movement in a particular direction.
  44. Which of the following would not move freely across the cytoplasmic membrane?
    Positively charged hydrogen ions
  45. How is osmosis different from simple diffusion?
    Water movement is driven by the concentration of solutes rather than its own concentration.
  46. allow a variety of molecules to cross the cytoplasmic membrane.
    Nonspecific permeases
  47. What will happen to a cell that is placed in a solution containing a high concentration of sugar, a molecule that cannot pass across the cell membrane?
    The cell will lose its interior water, causing it to shrivel up and possibly die.
  48. How is simple diffusion different from other types of passive transport?
    Simple diffusion does not require a permease.
  49. What type of transport uses two transport proteins?
  50. Sodium and potassium ions need to be pumped simultaneously against their concentration gradients. Which one of the transport proteins would be most effective at this?
  51. Why are ATPases associated with active transport proteins?
    They provide transport proteins with the energy needed to pump molecules against their concentration gradients.
  52. Efflux pumps can be used to pump antibiotics out of a cell once they enter to protect the cell. This will be done against the concentration gradient of the antibiotic. Which of the active transports would most likely be used?
  53. Which of the active transport types employs diffusion?
  54. Why is ATP necessary for active transport?
    ATP provides energy to transfer material against its concentration gradient.
  55. Which type of active transport protein moves two molecules into the cell at the same time?
  56. Which transport protein employs transporters that move molecules only in one direction?
    Uniport and Symport
  57. Which molecule shown in the animation, the square or the circle, is moving against its concentration gradient?
    Both the circle and the square
  58. Which type of active transport protein uses one protein to pump two different molecules?
    Antiport and Symport
  59. Where is the genetic information of the cell stored?
  60. The structural framework in a cell is the
  61. Where in a cell is ATP made?
    ATP is made in mitochondria.
  62. What carries instructions for making proteins from the nucleus into the cytoplasm?
    The "m" in mRNA stands for "messenger"; mRNA is the messenger that carries genetic instructions from the nucleus to the cytoplasm.
  63. One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by
    Ribosomes dock on the rough ER, and proteins are completed inside the rough ER.
  64. Which of the following is part of the endomembrane system?
    The endomembrane system includes the ER, the Golgi apparatus, lysosomes, and vesicles. It manufactures, processes, and transports lipids and proteins. The Golgi apparatus processes and packages proteins.
  65. Which of the following organelles breaks down worn-out organelles?
    Lysosomes contain digestive enzymes and break down worn-out organelles.
  66. Where are lipids made in the cell?
    The smooth ER makes lipids.
  67. What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?
    The plasma membrane surrounds the cell and regulates the movement of materials into and out of the cell.
  68. Peptidoglycan is a polymer of millions of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) sugars based on glucose molecules linked together in long chains cross-braced with four amino acids that link individual polymer chains together in a chain-link fence pattern. Layers of cross-braced NAG and NAM sheets are stacked vertically and held together by proteins with lipid anchors attached to the cell’s cytoplasmic membrane to form a scaffold of sugars and proteins that is able to hold the bacterial cell’s shape, even in response to extreme osmotic pressures. How would you expect a microbiology student to be able to describe the composition of peptidoglycan?
    • What is the composition of the peptidoglycan layers found in the cell wall of bacteria?
    • short amino acid chains, NAG, NAM, and some lipid proteins
  69. single lipid bilayer membrane, thick layer of peptidoglycan, teichoic acid is
    Gram pos
  70. dual lipid bilayer membrane, thin layer of peptidoglycan, periplasmic space, lipopolysaccharides is
    Gram neg
  71. A cell wall is a requirement for all living bacteria.
  72. Image of a single round bacterium.
  73. Image of a single rodishaped bacterium.
  74. Image of a cluster of round bacteria.
  75. Image of a string of rodishaped bacteria.
  76. Image of a vibrio (commaishaped) bacterium
  77. Image of a corkscrewishaped spirochete bacterium
  78. With the description of the different cell walls, membranes, and associated proteins set in the students' minds, you now need to introduce them to the idea that the cell wall can also act as a foundation to build things upon. Bacterial appendages require a strong foundation that will offer the support needed to move and function in a dynamic world. For example, flagella are long, whiplike protein structures that are used by many Gram-positive and Gram-negative bacteria for locomotion. In order to function effectively, a flagellum must be firmly anchored to the cell wall. How will you be able to get across the idea that the peptidoglycan cell wall is strong enough to support such a mechanism? With a protein rod that passes through the cell wall and protein rings used to anchor it in the membranes, these basal bodies are the rudimentary biological motors that use ATP power to spin the hook and the flagella attached to it.
    • Bacterial flagella have a biological motor that spins within the cell wall and is powered by ATP. This allows the flagella to spin in a whiplike motion to propel the bacterium
    • The biological motor that spins the flagella for bacterial propulsion is powered by the electron imbalance across the membrane that generates a gradient that the cell can harness for energy via proton motive force.
  79. Peptidoglycans are composed of sugars and _____.
    Amino acids combine to form the peptide portion of the peptidoglycan.
  80. One chain of alternating NAGs and NAMs is connected to another chain via _____.
    Tetrapeptides are composed of four amino acids and make up the "peptido" portion of peptidoglycan
  81. One of the main differences between a Gram-positive and a Gram-negative bacterial cell wall is that the peptidoglycan portion of a Gram-positive cell wall is _____ as compared to a Gram-negative cell wall.
    The peptidoglycan layer of Gram-positive bacteria is much thicker than that of Gram-negative bacteria
  82. Within the peptidoglycan layer, the crossbridges that connect the chains of alternating sugar molecules extend between _____.
    The crossbridges link NAM molecules to one another and provide the structural integrity of the peptidoglycan layer
  83. The peptidoglycan cell wall of bacteria is most analogous to _____.
    a chain-link fence
  84. What role do the teichoic acids play within the cell wall of Gram-positive bacteria?
    They serve to stabilize the cell wall and hold it in place.
  85. The region between the outer and inner membranes of a Gram-negative bacterial cell is known as the __________, and it is the location of enzymes that assemble peptidoglycan.
    periplasmic space
  86. A patient is infected with Gram-negative bacteria and is experiencing only mild symptoms. When the patient is given an antibiotic causing lysis of the bacterial cells, he suddenly experiences an increase in inflammation and fever, as well as the formation of blood clots. What explanation best describes what happened?
    The lysis of the cells releases lipid A from the lipopolysaccharide layer.