Micro test #2

  1. Defenses of the GI tract
    • mucus
    • secretory IgA
    • peristalsis
    • some fluids have antimicrobial properties: saliva, stomach fluid, and bile
    • GALT tissues (gut associated lymphoid tissues): tonsils, adenoids, lymphoid tissue, in the esophagus, Peyer's patches, and appendix
  2. Define peridontitis
    What can it cause?
    • Extension of gingivitis into the periodontal membrane and cementum
    • Increases the size of pockets between the tooth and the gingival
    • Can cause bone resorption enoughg to loosen and lose the tooth
  3. The most common infections disease of human beings is:
    Dental Carries
  4. 1) Initial stage of periodontitis:
    2) If this persists it can:
    • 1) gingivitis
    • 2) develop extension of gingivitis into the periodontal membrane and cementum; and increase the size of pockets between the tooth and gingiva. Can also cause bone reabsorption enough to loosen and possibly lose teeth. (the definition of periodontitis)
  5. Mumps is caused by:
    Initial symptoms
    • The paramyxo virus
    • Fever,malaise, ms pain
  6. The initial symptoms of mumps may be followed by...
    • Inflammation of the salivary glands producing popherlike swelling of the cheeks
    • AKA- parotitis
  7. __________ is a ________ that causes gastric ulcers
    Also linked to a variety of gastrointestinal ailments:
    • Heliobacter pylori; bacteria
    • Gastritis
    • Deodenal ulcers
    • Severe ulcers
    • Long term infection can cause stomach adenocarcinomas
  8. 0157:H7
    Enterohemorrhagic E. coli (EHEC)
  9. EHEC causes symptoms of:
    • bloody diarrhea
    • some pts can develop hemolytic uremic syndrome (HUS)
    • Can also cause neurological symptoms
  10. Salmonella typhi AKA
    Typhoid fever
  11. Shigella symptoms
    • Causes acute diarrhea
    • Causes the most severe forms of dysentery (watery stools)
  12. Enterotoxigenic E. coli (ETEC) AKA
    • Traveler's diarrhea
    • fever, nausea, vomitting, watery diarrhea
  13. Campylobacter
    In rare cases can lead to
    • Most common BACTERIAL cause of diarrhea in US
    • Is an STD that affects sheep, goats, and cattle and can cause spontaneous abortions in women late term
    • Comes from chicken
    • In rare cases, it can cause Guillian-Barre syndrome
  14. Clostridium difficile
    Major cause of...
    Can cause...
    Treated with...
    • Major cause of diarrhea in hospitals: nosocomial infection
    • Causes pseudomembranous colitis
    • Produces 2 enterotoxins that create areas of necrosis in the wall of the intestine
    • Is treated with Flagyl
  15. Vibrio cholera
    • Symptoms begin abruptly
    • Copious watery feces called secretory diarrhea
  16. Cryptosporidium
    In certain people...
    Can cause...
    In AIDs pts, may develop into chronic persistent cryptosoridial diarrhea
  17. Rotavirus
    • Causes damage to the intestine
    • Primary VIRAL cause of diarrhea worldwide
    • Infects humans, calves, and piglets from fecally contaminated food
  18. Ascaris lumbricoides
    • Larvae/ worms
    • Can emerge from the nose and mouth
  19. Necator americanus
    • Larvae/ worms
    • Infects by penetrating the bare feet
    • Can be carried through the blood to the heart and lungs
  20. Facilitated diffusion
    • Utilizes a carrier protein
    • Exhibits saturation which limits the rate of a substance if there are a low number of binding sites on the transport proteins
  21. Active transport
    • Requires the expinditure of energy
    • Items that require actve transport are: AA, organic acids, phosphates, and metal ions
    • Example is endocytosis
  22. Environmental factors that affect microbes
    • Microbial cells cannot control thier temp, so they assume the ambient temp of thier environment
    • Optimum temp: promotes the fastest growth
    • pH
    • Osmotic pressure
    • Barometric pressure
  23. Psychrophile
    • A microorganism that has an optimum temp below 15d C and is capable of growing at 0d C
    • Listeria is an example
  24. Mesophile
    • Optimum growth temperature of most mesophiles is 20-40d C (room temperature)
    • Most human pathogens are mesophiles and have optimum between 30-40d C
  25. Thermophile
    • A microbe that grows optimally at temperatures greater than 45d C
    • Likes warmer environment
  26. Obligate (strict) aerobe:
    Cannot grow without oxygen
  27. Facultative
    An aerobe that is also capable of growth in the absence of oxygen
  28. Obligate (strict) anaerobes
    Cannot tolerate any free oxygen in the immediate environment and will die if exposed to it.
  29. Aerotolerant anaerobes
    Do not utilize oxygen, but can survive and grow to a limited extent in its presence
  30. Microaerophile
    Does not grow at normal atmospheric concentrations of oxygen but does require a small amount of oxygen in metabolism
  31. Majority of organisms live or grow in habitats b/t _______ pH
  32. Osmophiles vs. Halophiles
    • Osmophiles live in high solute (sugar) concentrations
    • Halophiles prefer high salt concentrations
  33. Mutualism
    A type of symbiosis in which both organisms benefit
  34. Commensalism
    A type of symbiosis in which one organism is benefited and the other is unaffected
  35. Parasitism
    A type of symbiosis in which one organism is benefited and the other is harmed
  36. Synergism vs. Antagonism
    • Both are types of non-symbiotic relationship
    • Synergism- Free living organism; organisms benefit, but isnt necessary
    • Antagonism- Free-living species that arise when members of the community compete; one microbe secretes a chemical substance into the environment that inhibit or destroys another microbe in the same environment
  37. Binary fission
    The basis of population growth
  38. 2 ways microbial growth occurs
    • Growth takes place on 2 levels
    • - cell snthesizes new cell components and increases in size
    • - the number of cells in the population increases
  39. The population growth curve
    • Is a predictable pattern
    • Has 4 phases
    • Lag phase: flat period, first part of curve, not yet multiplying at optimal rate
    • Eponential growth phase: maximum cell division
    • Stationary growth phase: death balances out the rate of multiplication, depleted nutrients and oxygen stores
    • Death phase
  40. Enumeration of bacteria
    Total cell count
  41. Chromosomes in bacteria are ________ in shape
  42. Basic unit of DNA structure is a
  43. Nitrogenous base purines
    • Adenine
    • Guanine
  44. Nitrogenous base pyrimidines
    • Thymine
    • Cytosine
  45. Helicase
    Binds to the DNA at origin and unzips the DNA helix by breaking hydrogen bonds
  46. Function of DNA poymerase III in DNA replication
    • Can only continue to add nucleotides to an already existing chain, so start with RNA primers put on first by enzyme primase
    • Proofreads the chain for mistakes
  47. Primary function of primase
    Synthesizing an RNA primer
  48. Function of DNA polymerase I in DNA replication
    • Removes RNA primers and replaces them with DNA
    • Closes gaps
    • Repairs mismatches
  49. Primary function of ligase
    • Final binding of nicks in DNA during during synthesis and repair
    • Connects the Okazaki fragments
  50. Occasionally an incorrect base is added to the growing chain. If this is not corrected, ________ result
  51. Okazaki fragments
    Short fragments of DNA which are linked together by ligases
  52. The master code of DNA is used to synthesize an RNA molecule through a process called:
  53. The information in the RNA is used to produce proteins through a process called
  54. Each triplet represents a code for a particular _________
    Amino Acid
  55. When the triplet code is transcribed and translated, it dictates the type and order of Amino Acids in the __________
    Polypeptide chain
  56. RNA vs. DNA
    • RNA
    • - A single stranded molecule
    • - Contains uracil
    • - Sugar is ribose
    • DNA
    • - Double stranded
    • - Contains thyamin
    • - Sugar is deoxyribose
  57. Function of mRNA
    • Carries out DNAs message
    • A transcription of a structural gene or genes in the DNA
  58. Function of tranfer RNA
    • The key to Translation
    • A copy of a specific region of DNA
    • Brings AA to ribosome during tranlation
  59. Function of rRNA
    Forms the major part of a ribosome and participates in protein synthesis
  60. Biota
    Beneficial or harmless resident bacteria commonly found on and/or in the human body
  61. Prokaryotic ribosome is composed of tightly packed _____ and __________
    rRNA; Protein
  62. The second stage of gene expression
  63. Modifications to proteins may be necessary if:
    • The starting AA is clipped off
    • Cofactors are added
  64. Operons
    • Collections of genes
    • All are regulated as a single unit
  65. 2 types of operons
    • Inducible: the operon is turned on (or induced) by the substrate of the enzyme for which the genes code
    • Repressible: turned off by the product synthesized by the enzyme
  66. Mutations
    • An alteration in the nitrogen base of DNA
    • When phenotypic changes are due to changes in the genotype
  67. Wild type vs. mutant strain
    • Wild type: a microorganism exhibits a natural, nonmutated characteristic
    • Mutant strain: when the microorganism bears a mutation
  68. Spontaneous mutation:
    Random change in the DNA arising from errors in replication
  69. Induced mutation:
    Results from exposure to known mutagens
  70. Point mutations:
    Involve addition, deletion, or substitution of single bases
  71. What are the 4 types of point mutations?
    • Missense
    • Nonsense
    • Silent
    • Back
  72. Missense vs. nonsense
    • Missense: change that leads to placement of a diffferent AA
    • Nonsense: changes a normal codon into a stop codon
  73. Silent mutation:
    Alters a base but does not change the AA and thus has no effect
  74. Back mutation
    When a gene undergoes a mutation and then reverses back to its orginal base composition
  75. Frameshift mutations:
    Mutations that occur when one or more bases are inserted into or deleted from a newly synthesized DNA strand
  76. Polymerase I and Polymerase III can both read for mutations
  77. Recombinant organism:
    Any organism that contains (and expresses) genes that originated in another organism
  78. Types of Intermicrobial Exchange
    • Conjugation- Donor cell with pilus; direct; genes transferred- toxin production
    • Transformation- Free donor DNA; Indect; genes transferred- Polysaccharide capsule
    • Transduction- Defective bacteriophage is carrier of donor DNA; Indirect; genes transferred- Toxins
  79. Bacteriophage
    A virus that specifically infects a bacterial cell
  80. Repair of mutations- DNA that has been damaged by UV radiation
    Restored by photoactivation or light repair
  81. Repair of mutations- Excision repair
    • Excise mutations by a series of enzymes
    • Remove incorrect bases and add correct one
  82. Repair of mutations- Most DNA damage is resolved by
    Enzymatic systems specialized for finding and fixing such defects (DNA polymerase I and III)
  83. Jaundice
    • Yellow discoloration of the skin and other membranes caused by accumulation of bilirubin
    • Associated with liver infection as with Hepatitis infections
  84. Eosiniphilia
    An increase in eosinophil concentration in the bloodstream commonly due to helminth infections
  85. Hepatitis A virus
    • Food-bornes
    • Non-oncogenic
  86. Hep B
    • Fluid-borne
    • Can develop into liver disease
    • Can be oncogenic
  87. Hep C
    • Blood-borne
    • Oncogenic
    • Usually will need transfusions
  88. Streptococcus mutans
  89. Staphylococcus aureus
    • Exotoxin
    • Found in potato salads, custards, and pastries
    • Heating wont prevent disease
    • Wont alter the smell or taste of the food
  90. Clostridium perfringens
    • Exotoxin
    • Caused when vegetables or beans have not been cooked thoroughly enough to destroy endospores
  91. Bacillus cereus
    • Exotoxin
    • Found in foods that are kept warm for long periods of time
  92. Giardia
    • Stools have a greasy, malodrous quality
    • Causes lots of flatulence
  93. Taenea solium
    Intestinal distress as the primary symptom
  94. Contributing factor to dental caries
  95. When symptoms are violent and incubation period is short, ________________ should be considered rather than ______________
    Intoxication; infection
  96. Food poisening is usually caused by an
  97. Virulence factors
    • Specialized mouthparts
    • Enzymes
    • Cuticle or other covering
  98. The definitive host is where the ________ __________ is found
    Adult worm
  99. Trace elements
    Micronutrients (Zinc, Nickle, Mn) that occur in small amounts and are involved in enzyme function and maintenence of protein structure
  100. Essential nutrients must be
    provided to the organism in the diet
  101. Obligate intracellular parasite
    Must grow and live inside the host
  102. Heterotrophs
    An organism that relies on organic compounds for its carbon and energy needs
  103. Where do heterotrophs get thier carbon?
    From glucose (in organic form)
  104. Autotrophs get their carbon from
    Inorganic sources (CO2)
  105. CHOPS N
    • Carbon
    • Hydrogen
    • Oxygen
    • Sulfur
    • Nitrogen
  106. Roles and resources of CHOPS N
  107. Conjugated enzymes
    Contain protein and non-protein molecules
  108. Endoenzyme vs. exoenzyme
    • Endoenzyme is the breakdown of molecules inside of the cell (function of virulence factors)
    • Exoenzyme breaks down molecules outside the cell
  109. Cofactors
    • Support the work
    • Metallic cofactors: activate enzymes and bring the active site and substrate closer together; inorganic
    • Coenzymes: form an alteration of a substrate; removes a chemical group; Vitamins are one of the most important components of coenzymes; organic
  110. Haloenzyme
    • A conjugated enzyme
    • A combination of a protein and one or more cofactor
  111. Catalase
    Breaks down hydrogen peroxide
  112. Oxidase
    Adds electrons to oxygen
  113. Urease
    Splits urea into an ammonium ion
  114. Nitrate reductase
    Reduces nitrate to nitrite
  115. DNA polymerase complex
    Synthesis of DNA
  116. Fermentation end products
    • Alcoholic beverages
    • Dairy products
    • Vitamins
    • Hormones
    • Antibiotics
  117. Constitutive vs. regulated enzymes
    • Constitutive: Present in bacterial cells in constant amount
    • Regulated: The extent of transcription and translation is influenced by changes in the environment
  118. 3 ATP formation mechanisms
    • Oxidative phosphorylation
    • Substrate level phosphorylation
    • Photophosphorylation
  119. Competitive inhibition
    Blocks the active site
  120. Non-competitive Inhibition
    Has 2 binding sites: regulatory and active
Card Set
Micro test #2
Organims that infect the gastrointestinal system, microbial nutrition, metabolism of microbes, genetics