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2012-03-21 09:47:20

Exam 2
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  1. What characteristics distinguish catabolism from biosynthesis(anabolism)?
    • Catabolism: breaking down reactions usually release energy
    • Biosynthesis: buildin up reactions usually consume enegy (must have energy supply.)
  2. What are the two mechanisms by which living cells store metabolic energy?
    • High energy storage carrier molecules ATP(nucleotide) Also GTP.
    • Peter mitchell chemiosmotic hypothesis: Protin gradient acrross cell membrane
    • sodium gradient
    • Due to ion gradient across the membranes due to concentration difference and electrical
  3. What is the most abundant high-energy carrier molecule found in cells?
    ATP- Nucleotide
  4. How is its molecular structure suited for this purpose?
  5. How does the proton gradient store energy?
    • pump proton out and set up protoen gradietn acrross cell membrane
    • can use that same proton if re-enter
    • once puped out thay cant come back in unless
    • Concentration of H+s
    • electrical charge
    • Difference: enegery between outside and inside cell membrane.
  6. How do cells(when growing nonphotosynthetically) dispose of the extra hydrogen atoms generated by their catabolic activities?
    if breaking glucose all the way down to carbon dioxide by aerobic respiration, generate 24 H to get rid of, simply by sticking monooxygen convert that to water, couples reductionof oxygen with additional ATP syhtesis, electron transport cell membrane allows to pump more protons from the inside to the outside builds up a proton gradient which can be converted back to ATP by an ATP synthase ezyme, in the cell it can also breaddown ATP to built a proton gradient
  7. What is the most abundant hydrogen-atom carrier molecule found in cells?
    • NAD
    • picks up two electron and on proton the other one is released into the cytoplasm can serve as a source in order to buitl up the proton gradient
  8. What is an oxidation-reduction(redox) reaction?
  9. How do oxidation and reduction relate to hydrogen atom disposal?
  10. What distinquishes fementation and reperiration as different types of energy-generating metabolism?
    • Fermentation: is metabolism in which energy is derived from the partial oxidation of an organic compound using organic intermediates as electron donors and electron acceptors. No outside electron acceptors are involved; no membrane or electron transport system is required; all ATP is produced by substrate level phosphorylation.
    • Respirations: result in the complete oxidation of the substrate by an outside electron acceptor.
  11. How are certain bacteria able to sustain a lactic acid fementation (from glucose) with respect to ATP formation and hyrdrogen atom disposal?
    • mixed acid fermentation: end products latic acid, acetic acid,formic acid,pathway of enterebactrae
    • Butanediol fermentation:
  12. What is the underlying metablic reason for the results given by different bacteria in the methly red and voges-Proskauer biochemical test?
  13. Why is areobic resperiation a much more energy-efficient metabobolic process than fermentation?
  14. What major enzyme pathways are involved in aerobic respiration?
  15. What functions are fulfilled by electron transport chains?
    • proton pump
    • reducing oxygen transfer NADH ot other H donors to oxygen
  16. What types of components comprise a typical electron transport chain?
    • non heme iron sulfur
    • quinons
    • cytochromes
  17. How does ATP synthase function in cellular energy metabolism?
  18. What is the difference between substrate-level and oxidative phosphorylation?
  19. What are the most common modes of microbial cell division?
  20. What factors can influence the doubling(generation) time of a bacterial culture?
    Varies with species and culture condition
  21. What is the exponentail growth equation?
    • N=No2n
    • n=number of cells at time (t)
    • No = # of cell a tim (t0)
    • n=number of doublings
    • logN=logN0+
  22. Know how to solve it for the vvalue of the unknown vairable?
  23. What factors limit expnential growth of bacterial population in the real world?
    • Temperature
    • nutrition
    • built up of waste
    • protozoa predators
  24. Name the four phases of the bacterial growth curve?
    • Phase A/1: lag phase
    • Phase B/2: logarithmic or esponential growth phase
    • Phase C/3: maximum stationary phase
    • Phase D/4: death or decline phase
  25. What is the physiological state of the cells in each phase(what are they doing)?
  26. How do we categorize living organisms on the basis of energy source?
    • Phototraph: an organism that derives its energy from visible light, metabolic energy is generated via (photophosphorylation)
    • Chemotroph: an organism that derives its energy from a chemical source(without using light energy). Metabolic energy is generated via (Fermentation and/ or Respiration)
  27. How do we catagerize living organisms on the basis of carbon source?
    • autotroph: an organism that uses cabon dioxide (CO2) as a sole carbon source (via carbon dioxide fixation).
    • Heterotroph: an organism that requires an organic source of carbon.
  28. In terms of dry wight, what are the most abundant elements in living cells?
    carbon > oxygen > nitrogen > hydrogen > phosphrous
  29. Why is moleculare oxygen O2 toxic to some microorganisms?
    to cells that do not habe enzymes capable of efficiently destroying the reactibe oxygen species
  30. What defenses do microogransims have against these toxic effects?
  31. How do we categorize living organisms on the basis of their oxygen relationships?
    • Strict aerobic- require O2 for growth
    • strictanarobic- cannot use O2 for growth and are usually killed by it
    • Facultative anerobic: can use O2 for growth when available but will also grow if its absence
    • Aerotolerant anaerobes: cannot use O2 for growth but will grow in the presence
    • Microaerophiles: require O2 for growth but can only grow at reduced O2 concentrations(spirilla)
  32. What do the minimum, optimum, and maximum temperatures of microbial grwoth describe?
    Their own optimal growth temperater
  33. How do we categorize living organisms on the basis of their temperature relationships?
    • phychrophile: 0-20c optimal growth
    • mesophile: 20-45 c
    • thermophile: 44- 95c
  34. What are microogranisms adapted to high pressure called and what is the most obvious natrual environment where you would find them?
  35. How are microorganisms able to grow in high-salt enviroments,and what are they called?
    • Halphiles
    • by able to replace it sodium with other cations such as potassium
  36. What is pH and how is it defined?
  37. How are microorganisms able to grow in high- or low-pH environments, and what are they called?
  38. What are the definitions of mircrobiostatic, microbicidal, and sterilizing agents?
    • Microbiostatic: an agent that inhibits the growth of mirovial cell but does not necessarily kill them
    • Micrbicidal Agent: an agent that kills microbial cells but does not necessarily destroy resistant forms such as endospore
    • Sterilizing Agent9extreme): an agen that kills all forms of lice (microbial cells and endospores).
  39. Can an object be partially steril? Why or Why not?
  40. What is the difference between thermal death time and thermal death point measurements of microbial killing by heat?
    • Thermal Death Point: the lowest temperature at which all cells in a standard suspension of bacteria are killed in 10 mins
    • Thermal Death times: the shorter period of the time required to kill all cells in a standard suspension of bacterial at a specified temperature.
  41. How does killing microbial cells by dry heat differ from killin by moist heat?
  42. How can cold be used to control microbial growth?
    • With two basic purposes
    • temper growth and to preserve strains
    • bacteria grows slowly but also die slowly
    • most pathogens are mesophilic and grow poorly
    • gram positive listeria monocytogens can grow
  43. How can desiccation be used to control microbial grwoth?
  44. How can osmotic pressure be used to control microbial growth?
    salt, syrup, draws water outside of cells
  45. How can filtration be used to control microbial growth?
    • solution passes through the filter bacteria get stuck in the filter and liquid goes through
    • 2 principles
    • Cant remove viruses
  46. What properties of filters are important for trapping microbial cells?
    • 1.Small pore size
    • 2. electrostatic interaction
    • negatively charged bacteria
    • positively charged filters
  47. How can irradiation be used to control microbial growth?
    • useful only for surface strilization
    • gamma rays
    • electron beams
    • x-rays
    • form transent ractive chemicals that damage DNA and scrabmle genetic infromation. will dye trying to replicate,
    • not effective against viruses or prions
  48. How do ultraviolet light and ionizing radiation differ in how they kill microbial cells?
    • ultraviolet light: useful only fro sruface serilization
    • ionizing: attacks the source like water that mirobial cells use
  49. What are the definintions of disingectants, antiseptic, and snaitizers?
    • antispeptic: a microbicidal or microbiostatic agent that is used on living tissue
    • Disinfectant: a microbicidal agent that is used on inanimate ojbects and surfaces
    • Sanitizer: an agent that reduces microbial populations to state levels that meet public standards (usually 99% killing
  50. What four classes of chemical agents disrupt cell membranes and denature proteins?
    Antispetic and disinfentants
  51. What is the phenol coefficient?
    • Phenol carbolic acid joseph listter
    • natural occuring inlignent woody parts of the plants
    • first also the standard for effectiveness
    • phenol = 1
    • less effective than phenol <1
    • mor effective than phenol > 1
  52. How do surfactants reduce surface tension?
    • Water molecules on the surface will get pulled down by the underneath molecules
    • makes as kin on the surface and provide a struture alon the surface
    • detergans, soaps destroy tension which makes it easy to desrupt the proetin in microbial organism, or removed,
  53. What four classes of chemical agents inactivate enxymes reacting whith chemical groups essential for activity?
  54. What two classes of chemical agents kill or inhibit microbial growth by other mechanisms?
  55. What role did the following scientists play in the history of antimicrobial chemotherapy; Paul Ehrich, Gerhard Domagk, Alexander Fleming, and Selman Waksman?
    • Paul Ehrlich: synthesis of chemotherpeutic agent in the laboratory.
    • synthetic drugs
    • Gerhard domagk: discovered prontosil cured streptococoal infections
    • Selman Waksman & albert shatz: isolation of aminoglycoside antibrotie streptomycin produced by streptomyces greseus. The fist effective treatment for tuberculosis.
    • Alexander Fleming: discovered od beta-lactam antibiotic pencillin, produced by penicillium notatum.
  56. What basic principle guides the search for new chemical compounds that will destroy microbes in vivo without harming patient?
    • Selective Toxicity: the ability of a chemotherapeutic agent to kill or inhibit disease-causing microbes without harming the patient.
    • chemotherapy: the invivo use of chemical agen to treat disease.
  57. What distinguishes and antimicrobial drug from an antibiotic?
    • Antibiotics: are only those substances that are produced by a microorganism that can kill or prevent the growth of another microorganism
    • Antimicrobials: include antibiotics as well as synthetically formed compounds.
  58. How does sulfanilamide (the first sulfa drug) exert its antimicrobial effect?
    • Analog: a chemical compound with similiar structive as another compound
    • Sulfanilamide: blocks synthesis of the vitamin folic acid.
    • compettitive inhibition
    • has a compound called pterin ring-teron
  59. What genera of bacteria and fungi produce most of our medically important anibiotics?
    • Gram-positive bacteria, streptomyces, and related genera
    • (tertracyclines,chloromphenicol, rifamycins, aminoglycoside,macrolides,and polyenes) bacillus.
    • Acremonium (cephalosporins.)
  60. What is the difference between a narrow-spectrum versus broad-spectrum antibiotic?
    Narrow Spectrum: antibiotica re effective against only one group of microorganisms.

    Broad specrtrum: antibiotics are effective against more than one group of microoganisms
  61. What are the four major modes of action by which antibiotics kill microbial cells?
    • inibition of cell wall synthesis
    • inibition of preotein synthesis
    • inbibition of DNA replication
    • Damage to cell membrane
  62. What are the modes of action of penicillin and tetracycline?
  63. How do antibiotic resistant microoganimsm commonly arise?
    through natural slection
  64. What are the most common mechanisms of antibiotic resistance?
  65. What are some problems that can be associated with the use of antibiotics?
    • toxic side effects, hearing problems
    • allergic reaction pencillin metabolism disreganize
    • overuse can supress the immune system
    • destruction of normal microbial flora
    • selection for anibiotic resistant microbes
  66. What are stromatolites?
    • mineralized malts
    • calcium carbonate whic become minerlized
  67. What distinguishes cyanobacteria from other photosynthetic prokaryotes in terms of their photosynthetic metabolism?
    The possesion of chlorphyll a and the use of oxygenic photosynthesis
  68. How do some filamentous cyanobacteria carry out nitrogen fixation?
    • uniccelular- long filaments
    • filamentous speceis can form mats interweave with each other
    • they can take nitrogen gas from atmospher and transform to organic form
  69. What are bacteriochlorophylls?
    green and purple, optimixed to observe light, blue green mor anerobic do not mix
  70. What distinguishes purple and green photosynthetic from other photosythetic prokarytoes in terms of their photosynthetic metabolism?
    • two different groups: carry out anoxygenic photosythesis they dont produce oxygen or use water.
    • more arobic do not mix
    • rich in hydrogen sulfide
    • areboic enviornments organ C compounds
  71. How do photosynthetic mircoorganisms grow in stratified (meromictic) lakes?
    • sulfur containing
    • H2 and reduced organic
    • compond to reduece C02
    • anerobic environments
    • rich in hydrogen sulfide
  72. What are the unique metabolic aspects of nitrifying bacteria?
  73. What distinquishes the two different groups of these bacteria?
  74. What is a unique characteristic of some spirilla as discussed in lecture?
    • microaerophilic, aqauatic , amphitrious, glaggelar arrangements
    • they carry out magetotascis- sensitive to magetic fields(eath)because they contain magnotosomes in the cytoplasm which is composed of FE3O4 (magetite).
  75. What unqiue characteristics do hyphomicrobium and caulobacter possess?
    • stalked and budding bacterium
    • swarmer cell budding and prothecate bacteria
    • protheca= stalk commonly found in aquatic environment
  76. What is gliding motility, and what group of bacteria discussed in lecture have this characteristic?
    • motility not involving fagella must be in contact with surface
    • Myxobacteria-feed on other bacteria by digestice enzymes
  77. What is a unique chracteristic of the bdellovibrios?
    • has an attack cell
    • uses host resources to grow
    • uses the host cell as a protective invubator
  78. What physiological role does the fluorescent pigment produced by Pseudomonas aeruginosa play?
    • flourescent yellow pigment =produce siderophores
    • binds iron compounds
    • iron carring, light green color
    • siderophores <- pyooverdin.
    • produce blue pigment-pyocyanin antibiotic
  79. What two specific types of infections are frequently caused by P. aeruginosa?
    • cause, cystic fibrosis patient infections
    • burn patiens (caused infection
  80. What potentially deadly disease is caused by a member of the genus vibrio?
  81. What is a unique chracteristic of photobacterium, another member of this same family, and what enzyme is responsible for this chracteristic?
    • bioluminescent bacteria: have ability to produce light
    • lviferase( exnyme)
    • R+ long-chain hydrocarbon blue green light
    • controlled by cell density -quorum sensing only where a cell reaches a certain cell density
    • symbiotic associations with marine animals
    • flashlight fish
  82. What potentially deadly diseases are caused by certain members of the genera salmonella and shigella?
    • salmononella enteridits- enteroclitis
    • salmonelly typhi-systemic infection fever typhoid fecer
    • shigella dysenteriae-bacillary dycentery infection in the intestinal called baccillary dysentery
  83. What is the importance of bacteroides in the human colon?
    • carry out fementations carbohydrate fermentation
    • can be found in the rumen of grazing animals helps digest plant material
  84. What is a unique aspect of motility among the spirochetes?
    • motile by flagella by perplamic flagella or endoflagella
    • form robbons of flagella = axial filaments corkscrew
  85. What two potentially deadly diseases are caused by members of this group?
    • treponema pallidune: syphilis
    • borelia bugdorferi: lyme disease
  86. What is a fundamental, shared characteristic of the rickettsias and chlamydias?
    • obligate intercellular parasites
    • energy parasites
    • exchanged ADP to ATP
  87. What diseases are caused by rickettsias?
    • named after howard
    • epidemic typhys
    • Q fever- pasterized milk to prevent pasterization kills it
    • rocky mountain spotted fever - tick bite insect sector
  88. By chlamydias?
    • most common cause several disease in humans
    • clhamydia (STD)
  89. How does the concept of species differ between prokaryotes and eukaryotes?
    • 97% idetnical or aboce = same species
    • ssu rRna sequences
  90. What molecular technique is most widely used today to distinguish evolutinary lineages of microogranism?
    • by protein categorization
    • carl woese ribosomal RNA
    • 165 rRNA small subunit
    • 165= prokaryotes
    • 185 eukaryotes
  91. What makes this molecular technique appropriate for this purpose?
  92. What are the three domains of life?
    • Bacteria (prokaryotic)
    • Eukaryotes
    • Archaea