micrbio 21.txt

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micrbio 21.txt
2012-02-13 07:14:01

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  1. Microbiology
    study of organisms, (Microorganism/Microbe/Germ/Bug) too small to be seen with the unaided eye.
  2. Types of Microorganisms(4 main types)
    Bacteria, Fungi, Parasites, Viruses
  3. What are the two basic cell types?
    Prokaryotic & Eukaryotic
  4. What is the main similarity between eukaryotic and prokaryotic cells?
    Both have metabolic reactions
  5. What are the main differences between eukaryotic and prokaryotic cells?
    Cell structure and complexity.
  6. What are the four main parts to the structural organization of the prokaryotic cell?
    Appendages, Cell Enevelope, Cytoplasm and (sometimes) endospores.
  7. What are Cell appendages?
    Structures on the exterior surface of the cell that is used for motility and cell attachment.
  8. What is the cell envelope?
    The Outer wrapping "coat" of the bacteria.
  9. What is the cytoplasm?
    Internal matrix of the cell contained insdie the cell membrane.
  10. What are endospores?
    Mechanisms of survival (not all bacteria have it)
  11. What are three different kind of cell appendages?
    Flagella, Fimbriae/pili, sex pilus
  12. What is used to classify if a bacteria is motile or non-motile?
    The flagella
  13. Do all organisms have flagellum?
  14. Different arrangements of flagellum can be used for...
    ID purposes.
  15. How/why do flagellum move?
    due to directed movement
  16. Flagellum are influenced by positive and negative ___________ in the environment.
    chemotatic factors
  17. What is a positive chemotatic (chemotaxis) factor?
    Food (moving towards food)
  18. What is a negative chemotatic (chemotaxis) factor?
    predators (Moving away from predators)
  19. Is fimbriae/pili a virulent characteristic?
  20. Why is fimbriae/pili a virulent characteristic?
    • Because the function of fimbriae/pili is attachment. Bacteria can use this to attach to their
    • host.
  21. What are fimbriae/pili?
    Hair like particles coming off the surface of the bacteria.
  22. What is the main difference bwtween fimbraie and pilli?
    • fimbraie (fringed) are together and by the hundereds, while pili are present by theirselves or
    • at most in groups of three.
  23. Pili are composed of a protein called...
  24. Fimbraie and pili are both...
  25. What is the sex pilus?
    A hollow tube in which genetic info (DNA) can be transferred from one organism to another through a process called bacterial conjugation
  26. Define pathogenic.
    Ability of a bacteria to cause a disease.
  27. What are the three major components of the cell envelope?
    Glycocalyx, Cell Wall and Cell Membrane
  28. What is the cell envelope?
    Outer wrapping of the bacteria, the "coat"
  29. What is the glycocalyx?
    The outermost part of the cell envelope
  30. What are the two kinds of glycocalyx?
    Slime layers and capsules.
  31. Which glycocalyx is virulent? Slime layer or capsule?
    Both of them
  32. How is a slime layer virulent?
    inhibits the loss of nutrients, and aid in attachment with its stickiness.
  33. How is a capsule virulent?
    inhibits phagocytosis by white blood cells (anti-phagocytic)
  34. What are the main differences bewtween a slime layer and a capsule?
    • the gelatinous and thickness, or how tight the protein mix is bound to the bacteria's cell
    • wall.
  35. Do all bacteria have glycocalyx?
  36. What do slime layers and capsules have in common?
    Same composition = consists of polysaccharide protein
  37. What is the cell wall?
    the exoskeleton of the cell
  38. What gives bacteria their shape?
    The cell wall
  39. Why is the cell wall important for gram staining?
    • because different cell wall make ups have different staining retentions. Gives off different
    • gram stain differential stain.
  40. What is the bacterial exception to gram staining?
  41. Why is Tuberculosis the bacterial exception to gram staining?
    Its capsule is made of lipids, its nearly impossible to get dye to physically hold within the membrane.
  42. What protects the cell from osmotic lysis?
    Cell wall
  43. How does the cell wall protects the cell from osmotic lysis?
    confining the cell membrane
  44. Thickness of the cell wall depends on what?
    The cell type
  45. Whether a cell wall is gram positive or negative, what is one trait both walls share?
    It's walls contain heteropolymer peptidoglycan
  46. What does the cell membrane do?
    protects the cytoplasm
  47. What is peptidoglycan?
    glycan strands composed of linked NAM and NAG, With peptide bridges linking the NAMs.
  48. What are the 5 major components of the cytoplasm?
    Cell pool, nucleoids(chromatin body)Chromosome, plasmids, ribosomes, inclusion bodies/storage granuless
  49. Do all bacteria have endospores?
  50. What are the glycan chains in the cell wall?
    long polysaccharide chains of two repeating disaccharides
  51. NAG stands for..
  52. NAM stands for..
    N-acetylmuramic acid
  53. What are the glycan chains in the cell wall cross linked by?
    short tetrapeptide between M subunits
  54. What increases the rigdity of the cell wall?
    peptide bridges
  55. What kind of cell wall has multiple layers of peptidoglycan?
    Gram positive Cell Wall
  56. How many layers of peptidoglycan is in a gram positive cell wall?
    about 40 layers
  57. What makes up 10% of a gram positive cell wall?
    acidic polysaccharides
  58. What are the two acids that make up acidic polysaccharides?
    Teichoic acid and Lipoteichoic
  59. What are the functions of the teichoic and lipoteichoic acids?
    assist in the transport of ions and reinforce cross linking between glycan chains.
  60. NAMs and NAGs are both ...
    amino acids
  61. Which cell wall is more rigid? Gram positive or gram negative?
    gram positive
  62. Which cell wall is more complex in nature?
    Gram negative
  63. How many layers is in a gram negative cell wall?
  64. What are the three main layers of the gram negative cell wall?
    Outer membrane, periplasmic space (inner membrane), peptidoglycan.
  65. In the gram negative cell wall, what is external to the peptidoglycan?
    the outer membrane
  66. In the gram negative cell wall, how is the outer membrane semi-permeable?
    Because it allows the transfer of material across the inner memberane
  67. In the gram negative cell wall, what is the outer membrane made of?
    typical phospholipid bilayer
  68. What are the three specialized proteins contained within the outer membrane of the gram negative cell wal?
    lipopolysaccharides, lipoproteins, porin proteins
  69. Do lipoplysaccharides have hydrophobic or hydrophilic tendencies?
  70. What are porin proteins?
    protein channels used to transport thing across the lipid bilayers.
  71. What bands the whole bilayer together in the gram negative cell walls?
    porin proteins
  72. What is the periplasmic space?
    the narrow gap between in the inner and outer membrane
  73. What takes place in the periplasmic space?
    all synthesis and metabolic reactions
  74. What contains degragative or hydrolytic enzymes?
    the periplasmic space
  75. How many layers of peptidoglycan are found in the periplasmic space?
  76. How many layers of peptidoglycan are there in the gram negative cell wall?
  77. What happens when glucose enters the inner membrane?
    Hydrolytic enzymes break it down into 6 single carbons for energy in differnet metabolic reactions.
  78. gram positive and gram negative walls have this in common...
  79. What is the cell membrane?
    very thin flexible structure lying inside the cell wall, and molded completely around the cytoplasm
  80. What is the cell membrane made of?
    phospholipid bilayer containing specialized proteins on exterior of phospholipid bilayer, cant be in the hydrophobic tails.
  81. WHat are the two kinds of specialized proteins found with the phospholipid bilayer of the cell membrane?
    Integral and peripheral
  82. What is the difference between intergral and peripheral proteins?
    Intergal proteins have hydrophobic and hydrophilic tendencies because it is physically lodged into the the membrane and exposed on the exterior too. Periphreal proteins are strictly hydrophilic and are only fount on the exterior of the cell membrane, not in it.
  83. The cell membrane is a ________ permeable barrier
  84. What does the cell membrane retain?
  85. What is the site of metabolic activities attributable to organelles in eukaryote?
    Cell membrane
  86. What 6 metabolic activities attributable to organelles in eukaryotes happen at the cell membrane?
    respiration and photosynthesis, transport systems, synthesis of cell wall components, synthesis of lipids, secretion of exoenzymes, secretion of toxins (virulent factor)
  87. What three types of reactions happen at the cell membrane?
    synthetic reactions, transport systems and secretions
  88. What is the cytoplasm?
    internal matrix of the cell contained inside the cell membrane (dense gelatinous solution)
  89. What is the primary component of cytoplasm?
    water (70-80%)
  90. what is the cell pool?
    Complex mix of nutrients (carbs, amino acids, fatty acids and inorganic ions)
  91. What are the components of the cell pool/
    building blocks for cell synthesis (metabolism) or sources of energy (catabolism)
  92. What is the nucleoid?
    single circle of double stranded deoxyribonucleic acid (DNA) with specialized proteins (irregular mass within cytoplasm)
  93. What is the name of the minimal genetic info needed for bacterial survival ?
  94. Is the nucleoid enclosed by a membrane?
  95. What are plasmids?
    circular extrachromosomal strands of DNA found in most bacteria, but not all.
  96. What are the three advantages to having plasmids?
    antibiotic resistance, production of toxins(virulent), production of enzymes(aid in pathogenesis)
  97. What are Ribosomes?
    free floating (in cytoplasm) granules of RNA and proteins that function as sites for protein synthesis.
  98. Ribosomes resemble those of _______ cells but their composition is different.
  99. Inclusion bodies/granules
    amorphous particles floating in the cytoplasm and are composed of reserve nutrients stored during periods of abundance.
  100. What may contain polysaccharides (glycogen or starch) lipids (polymer of ?-hydroxy-butyric acid; PHB) or poly-phosphate (inorganic phosphate)?
    Inclusion bodies/granules
  101. Inclusion bodies/granules are dense when....
    the cell has a bounty of food.
  102. What are the three main things stored into inculsion bodies/granules?
    Organic storage granules - glycogan starch, Lipids - PHB, Inorganic phosphate
  103. What are endospores (spores)?
    mechanism of survival, all bacteria do not posses the ability to form endospores, only some do.
  104. Endospores are made in the cytoplasm of the gram positive bacteria, gram negative bacteria or both kinds of bacteria?
    gram positive
  105. What are two types of gram positive bacteria that is prime for endospores?
    Bacillus and clostridium
  106. What is the initiator of spore fermentation?
    unfavorable growth conditions (lack of nutrients)
  107. Can spores live independently on their own without a host?
    no, spores are deriveved from bacteria
  108. What is a dormant structure with no metabolic activity and no cell division?
  109. What environmental stresses are endospores very resistant to?
    heat, UV radiation, chemical disinfectants and dessication
  110. When do endospores germinate into a bacteria cell?
    when proper nutrients are present and the endospore becomes activated.
  111. When would a bacteria cell form a spore?
    when its under adverse conditions
  112. Breifly explain the process of a bacteria cell changing into an endospore then back to a bacteria.
    The cells try to hide, they undergo sporegenesis. when surroundings are good again and food and water is around, germinatiation occurs and morms a bacterial call again
  113. What is the function of the endospore?
  114. What does it mean to be a resting/dormant structure?
    to have no metabolic activity.
  115. What is the bacterial stationary phase
    when there is no increase in the number of bacteria.
  116. What is the bacterial death phase?
    then there is a decline in bacterial numbers.
  117. Why are bacteria specialized energy transformers?
    Because Bacteria preform their metabolism to make the energy that they need.
  118. Bacteria all have _________reactions but not all are the same.
  119. All bacteria convert ADP to ATP to...
    help store energy for the cells
  120. Bacteria can also store the energy in...
    thi-ester bonds.
  121. Bacteria can synthesize organic compounds needed by the cell by using what?
    the energy they created.
  122. What are the three metabolic classes of bacteria? -
    Heterotrophic, Photosynthetic, autotrophic
  123. All Heterotrophic bacteria are.
    pathogenic bacteria
  124. How do heterotrophic bacteria obtain their energy?
    obtain energy from organic compounds
  125. What bacteria can synthesize their own glucose?
    photosynthetic bacteria
  126. What bacteria does not use sunlight or organic compounds, but use s inorganic compounds (minerals, co2)?
    autotrophic bacteria
  127. Which bacteria are less apt to be pathogenic?
    Photosynthetic and autotrophic.
  128. What are the ways bacteria may generate energy ? (4 ways)
    Aerobic respiration (final electron acceptor = oxygen), Anaerobic respiration, Fermentation, photosynthesis
  129. What is the major energy-producing mechanism for aerobes?
    provides ATP and metabolic intermediates
  130. What are the three major pathways in aerobic respiration(linked together)?
    Glycolysis or glycolytic pathway, Krebs cycle (citric acid cycle), Electron transport chain-oxidative phosphorylation
  131. For all the aerobic respiration pathways, glucose is the most common..
    substrate =( the main energy source)
  132. For all the aerobic respiration pathways, Bacteria oxidizes glucose, which means what?
    it turns it into carbon dioxide, water and energy
  133. For all the aerobic respiration pathways how many molecules of ATP can be made off of 1 molecule of glucose?
    up to 38 molecules of ATP
  134. For the glycolytic pathway, what is the primary substrate?
  135. For the glycolytic pathway, what is the primary end-product?
  136. What is the 1st part of the glycolytic pathway?
    preparative (investment) phase.
  137. In the 1st step of the glycolytic pathway, how many ATPs are spent?
    2 ATP
  138. What is the 2nd part of the glycolytic pathway?
    the payoff phase
  139. How many ATPs and NADHs are gained in the 2nd part of the glycolytic pathway?
    4 ATPs and 2 NADHs
  140. In the glycolytic pathway, How many pyruvates does 1 glucose make?
  141. What is the net gain of ATP in the glycolytic pathway?
  142. NADH generates ___ ATPs by the Krebs Cycle
  143. How many pyruvates and glucoses does the Krebs Cycle start with from the glycolytic pathway?
    2 pyruvates and 1 glucose
  144. What kick starts the Krebs Cycle?
    acetyl coenzyme A
  145. Why is Krebs cycle a respiratory process?
    because it uses O2
  146. What is the initial step of the Krebs cycle?
    pyruvate decarboxylated to CO2 and acetyl coenzyme A
  147. What is the net gain of ATP, NADH and FADH2 in the later portion of the Krebs cycle?
    2 ATPs, 6NADHs and 2FADH2s
  148. How is the electron transport + oxidative phosphorylation started?
    The nadh and fadh2 are transferred into the cytoplasmic membrane.
  149. In the electron transport + oxidative phosphorylation what does the NADH and FADH2 need to make ATP?
    cytochromes and enzymes
  150. In electron transport + oxidative phosphorylation ,the nadh makes about ___ ATPs and the FADH2 makes about ____ ATPs .
    3, 2
  151. The molecule that gives away the electron is ...
  152. The molecule that receives the electron is...
  153. Electron transport and oxidative phosphorylation take place within the..?
    cytoplasmic membrane
  154. What is anaerobic respiration?
    Same exact thing as aerobic respiration except, O2 is not the terminal electron acceptor. Instead generally an oxygen-containing salt supplied in growth media, will help produce energy by reducing substrate
  155. What led to the discovery of anaerobic bacteria?
  156. Is fermentation primarily anaerobic and aerobic?
  157. What is the process of fermentation?
    An organic compound that is not O2 , is used as a terminal electron acceptor, produces less energy, but supports anaerobic bacterial growth.
  158. How is energy generated through fermentation?
    glycolytic pathway
  159. In fermentation, what are simple organic end products formed from?
    Anaerobic dissimilation or metabolism of glucose.
  160. In fermentation what are the end products of bacteria?
    Lactic acid, Ethanol, Acetic acid, Butyric acid
  161. How is ATP made in photosynthesis?
    Light is used for conversion.
  162. Is photosynthesis a feature of pathogenic bacteria?
  163. What are the end products of aerobic respiration?
    CO2 and H2O
  164. What micro-organisms use aerobic respiration?
    aerobes and facultative organisms.
  165. How many ATPs can possibly come out of electron transport?
    34 ATPs
  166. What is the final electron acceptor of aerobic respiration?
  167. How many ATPs is possible with anaerobic respiration?
    Less than 38
  168. What are the final electron acceptors in anaerobic respiration?
    Inorganic molecules and oxygen-containing salts
  169. What are the end products generated from anaerobic respiration?
    Hydrogen sulfide (H2s), nitrite, methane
  170. What micro-organisms use anaerobic respiration?
    Aerobes + some facultative organisms
  171. What is the number of possible ATP molecules that can be made in fermentation?
  172. What is the final electron acceptor in fermentation?
    Organic molecules
  173. What are the end products generated in fermentation?
    Ethanol, butanol, lactic acid
  174. What organisms use fermentation?
    Facultative organisms, Obligate anaerobes
  175. What kind of catabolism do all the major pathways use?
    Glucose or hexose
  176. In all the major pathways, Chemical energy is conserved by the formation of..?
    High energy compounds (ATP and ADP)
  177. In all the pathways, what is made in the preparative steps?
    Key intermediate compounds
  178. The major source of PO4 is what?
    ATP or ADP
  179. Can you get Inorganic phosphate from ATP or ADP?
  180. The phosphate that comes from ATP and ADP is used for what?
    Chemical energy
  181. Phosphate is renewed by what for the conservation of chemical energy?
  182. What is lost when phosphate is renewed for energy conservation?
  183. Each pathway generates what?
    NADH + H or NADPH + H
  184. What serves as reducing equivalents for all major pathways?
    1 NADH = 3 ATPs
  185. What is the potential energy generated for each pathway?
    1 NADH = 3 ATPs
  186. Mendel's work led to what two laws of inheritance?
    different characteristics are inherited separately and the fact that there are dominant and recessive traits.
  187. Garrod took mendel's work and made what important discovery?
    that there is a link b/t protein enzymes and genes
  188. How was it shown that there is a link b/t protein enzymes and genes? (explain)
    heat killed a smooth strain of disease in experiment. = mouse lives, so genetic info is carried. (r and heat killed s together... still killed the mouse) only DNAse inhibits transformation
  189. When was DNA identified?
    the end of the 1800s
  190. What is DNA?
    deoxyribonucleic acid (polynucleotide, organized into chromosomes.)
  191. Are the amount of bases A ant T always the same in DNA as is the amounts of C and G?
  192. What is the backbone of DNA?
  193. Watson and crick, used frankllin's photo 51 x ray to get nobel prize for what?
    DNA structure drawing.
  194. DNA is found in what?
    all living organisms
  195. There is usually just one _________ in bacteria (although more than one has been observed before).
  196. Chromosomes in bacteria are usually _________.
  197. The chromosomes in bacteria are usually ___ to ___ million base pairs long (most bacteria b/t 2-5)
    1/2 to 10
  198. Most bacteria have ________.
  199. What are Plasmids?
    Extra chromosomal DNA that replicate by themselves (independently of the chromosome)
  200. Plasmids are usually ________.
  201. Plasmids are usually b/t _____ and _____ million base pairs long.
    1,000 and 1.5
  202. How many plasmids can bacteria have?
    Some or none
  203. Plasmids have a copy number between __ and ______ (1 chromosomes, but up to 1,000 plasmids can replicate of the chromosome)
    1 to 1,000 (1 chromosomes, but up to 1,000 plasmids can replicate of the chromosome)
  204. Bacterial chromosomes are usually circular with 1-5 _______.
    Origins or replications
  205. Bacterial chromosomes are organized where?
    In a nucleoid
  206. What are Nucleoids?
    protein synthesis machines
  207. What are the three different types of plasmids?
    resistance, toxins and conjugation
  208. What are Resistance plasmids responsible for?
    carrying genes for antibiotic resistance
  209. What are Toxins plasmids responsible for?
    carrying toxin genes
  210. What are Conjugation plasmids responsible for?
    carrying information for conjugation
  211. Plasmids are not usually required for what?
    Survival of the cell
  212. Plasmids are used extensively in molecular biology for what?
    cloning and recombinant protein expression
  213. How is DNA is copied?
    DNA replication
  214. DNA replication is a semi-conservative replication, which means?
    one strand followed each daughter cell in the process
  215. What is the Mechanism of DNA replication? (6 steps)
    • 1-Binding of DnaA to replication origin (b/t 1-5 origins for bacteria, around 10,00 for humans)
    • 2-Open the helix with helicase = formation of replication fork,
    • 3-SSB (single strand binding)proteins hold single strand open,
    • 4-Primase and PNA polymerase primes for the leading strand,
    • 5-DNA polymerase adds new base pairs 5' to 3' (going backwards), a. Leading strand - continuous, b. Lagging strand - okazaki fragments requiring sealing w/ DNA ligase,
    • 6-Termination at specific termination sequences.
  216. How does DNA give rise to proteins?
    The Central Dogma
  217. What is The central dogma (57') process?
    1. DNA carries genetic information, 2. The transcription, the information is copied to RNA, 3. Through translation the information in RNA is translated into a polypeptide chain or protein.
  218. What is Transcription?
    Copying the genetic information into messenger RNA
  219. Genetic information is in what?
    the nucleus
  220. Proteins are synthesized where?
    on ribosomes in the cytoplasm (ribosomal RNA)
  221. What are messenger RNAs?
    Unstable RNAs that are translated by non-specialized ribosomes
  222. What are the 6 steps of the Transcription initiation phase?
    • 1. Transcription factors bind to promoter region (-10 and -35 bp before the start of the transcription,
    • 2. Promoters have important regulatory domains,
    • 3. RNA polymerase is recruited with the help sigma factors ( in bacteria most often sigma-70),
    • 4. DNA helix is unwound,
    • 5. The Promoter is cleared,
    • 6. Transcription Begins
  223. What are the 2 steps of the transcription Elongation Phase?
    • 1. RNA polymerase reads 3' to 5' and copies the template strand into a single stranded mRNA = makes an exact copy of the coding strand (light blue),
    • 2. mRNA contain the same bases as DNA except using uracil in place of thymine.
  224. What are the two versions of the Termination Phase?
    Rho independent and rho dependent
  225. What happens when the phase is Rho-independent?
    Transcription stops when the RNA molecule forms a G-C rich hairpin loop, followed by a string of U's (most common)
  226. What happens when the phase is Rho-dependent?
    The protein Rho destabilizes the interaction between mRNA and template and releases the new mRNA.
  227. What are the three steps in Translation? -
    • 1. Using proflavin-induced mutations in a T4 phage gene = insertion or deletion of three bases were required for translation of the gene (codon), 2. Crick postulated the presence of transfer RNA
    • expressing anti-codons, 3. Poly-U RNA showed in a cell free system that it made a polypeptide made up of only phenylalanine
  228. What is Transfer RNA?
    structural RNA molecules that transfer the amino acid to the ribosome based on the correct codon use. (every one has a specific anti codon and a specific amino acid. )
  229. What are Amino acids?
    they are the building blocks to make all proteins
  230. How many amino acids are there?
  231. ____________have one amino (NH2) group, and a carboxyl group (COOH) attached In the center is an "R" group which is different for each different one.
    Amino Acids
  232. When polypeptides are synthesized, the acid group of one amino acid is attached to the amino group of the next amino acid, forming a ______ bond.
  233. What are the four steps of Translation Initiation?
    • 1. mRNA binds through the ribosomal binding site (Shine-Dalgarno sequence) to the 30S ribosomal subunit = correct positioning.,
    • 2. IF1 blocks the A site and IF3 blocks the E site,
    • 3. IF3 helps the initiator methionine-tRNA bind to the P site.,
    • 4. The 50 S large ribosomal subunit then joins the complex.
  234. What are the two steps of the Elongation Phase for translation
    • 1. Met-tRNA binds to P site allowing next amino acid at A site and form a peptide bond (elongation on carboxyl end) ,
    • 2. The ribosome moves three bases (translocation) to allow new tRNA in enter A site and unloaded tRNA to exit from E site.
  235. What are the 3 steps of the translation Termination Phase?
    • 1. Three codons are called "stop codons." They code for no amino acid, and all proteins-coding regions end in a stop c,
    • 2. When the ribosome reaches a stop codon, there is no tRNA that binds to it. Instead proteins called "release factors" bind and cause the ribosome, the mRNA and the new polypeptide to separate. The new polypeptide is completed.,
    • 3. Note that the mRNA continues on past the stop codon. The remaining portion is not translated: it is the 3' untranslated region (3' UTR)
  236. What are the 5 major Cell Functions?
    • 1. DNA replication,
    • 2. RNA Transcription,
    • 3. RNA processing,
    • 4. mRNA transport,
    • 5. Protein Translation
  237. What are Mutations?
    changes in the DNA sequence that may be passed along to future generations.
  238. What are the three kinds of mutations?
    point mutations, silent mutations and missense mutations
  239. What are Point mutations?
    mutations with single base substitutions
  240. What are Silent mutations?
    Mutations that make no difference.
  241. What are Missense mutations?
    Mutations with an Amino acid change (Early stop codon).
  242. What are Deletion/insertion of small DNA segments ?
    Frame-shift mutation= changed reading frame
  243. Why is mutation important?-
    We need mutations for evolution
  244. What are the three stages of Bacterial DNA transfer?
    Transformation, transduction and conjugation.
  245. What is transformation in bacterial DNA transfer?
    the uptake of DNA from the environment (competent genes)
  246. What are the three steps in the transformation in bacterial DNA transfer?
    1. Donor DNA fragments and bin to surface of bacteria, 2. DNA is imported and becomes single-stranded, 3. Single-stranded DNA incorporates into host chromosomes
  247. What is Transduction in bacterial DNA transfer?
    Injection of DNA by phages (bacterial viruses)
  248. What is Conjugation in bacterial DNA transfer?
    Cell-mediated transfer of host genetic material
  249. In Bacterial DNA transfer, what is build within the last steps so that the DNA can actually transfer?
    Mating bridge (pilli 4)
  250. Most bacteria grow by?
    binary fission
  251. What is binary fission?
    Repetitive splitting
  252. Most bacteria will grow in artificial culture media with some exceptions; what are the exceptions?
    • Only on selective media (Legionella), Are obligate intracellular pathogens- meaning they require tissue or cells to grow (chlamydia), Require animal models (mycobacterium leprae), Have never
    • been grown (Treponema pallidum=can w/ animal models)
  253. Bacteria need Macronutrients to.
    grow and an energy source.
  254. Bacteria need micronutrients which are..
    (elements required in trace amounts)
  255. Bacteria need vitamins as growth factors because..
    if they cant make it on their own they can take vitamins from their host.
  256. What is a Phototroph?
    a microorganism that can derive all nutritional requirements for growth from the micronutrients and macronutrients supplied.
  257. What is a Fastidious bacteria?
    microorganisms that have complex and special nutrient requirements
  258. What kind of bacteria might require special vitamins or amino acids to grow?
    fastidious bacteria
  259. What are the two atmospheric conditions that bacteria may or may not want?
    CO2 and Oxygen
  260. What do some bacteria want as an atmospheric supplement?
  261. What does it mean when something is an obligate aerobe?
    It has an absolute requirement for O2
  262. What does it mean to be Microaerophilic?
    It has optimal growth at low O2 pressure.
  263. What does it mean to be a Facultative aerobe (facultative anaerobe)?
    it can grow either aerobically or anaerobically.
  264. What does it mean to be an Obligate anaerobe?
    it shows ideal growth in absence of O2.
  265. What are the four stages of bacteria growth?
    Lag phase, Logarithmic (exponential ) phase, Stationary phase, Death phase
  266. What is the bacterial lag phase?
    The initial beginning of growth
  267. What is the bacterial logarithmic (exponential) phase?
    When there is a great increase in numbers
  268. What is a bacteriophage?
    a bacterial virus "filterable agent"
  269. Why are bacteriophages important?
    Basis for recombinant DNA technologies, Clinical applications, provide means for genetic exchange, lysogenic conversion, insight into basic molecular biological processes.
  270. How are bacteriophages the basis for recombinant DNA technologies?
    T4 ligase, T& polymerase, cloning, etc.
  271. How are bacteriophages important for clinical applications?
    Bacterial typing, microbicides, linking to specific cells = id purposes, etc.
  272. How does bacteriophages provide means for genetic exchange?
    Spread of antibiotic resistance, etc.
  273. Why are bacteriophages important for lysogenic conversion?
    Alters bacterial virulence properties (acquisition of genes for bacterial toxins)
  274. How does bacteriophages give insight into basic molecular biological processes?
    Gene regulation, DNA replication, DNA repair, etc.
  275. In nm, how big is a T2 bacteriophage ?
    65 nm
  276. How do we culture and study bacteriophages?
    By "plaque assay" (what we do in lab)
  277. Explain the "plaque assay" process.
    1. add serial (1:10) dilutions of potential lysates to molten agar containing bacteria. Phage --> Cell 2. plate mixture onto solid agar culture medium, 3. Incubate overnight for a progressive infection
  278. How do we classify bacteriophages?
    Nucleic acid composition, shapes and lifestyle
  279. What are the different kinds of bacteriophatic nucleic acid that are possible?
    Double stranded DNA, Single stranded DNA, Double stranded RNA and single stranded RNA.
  280. What example of bacteriophage has double stranded DNA?
    T-phages, lambda,
  281. What example of bacteriophage has single stranded DNA?
  282. What example of bacteriophage has double stranded RNA?
  283. What example of bacteriophage has single stranded RNA?
  284. What shape is the φ6 bacteriophage?
    Icosohedral (geodesic dome)
  285. What shape is M13 bacteriophage?
    Helical (spiral staircase)
  286. What shape is the T Phage bacteriophage?
    Helical AND icosohedral
  287. What are the two classes of bacteriophage based on their lifestyles?
    Lytic and Temperate
  288. The lifestyles for bacteriophages are classified on the differences in their ________________.
    Replicative lifecycles
  289. What do lytic bacteriophages do to infected bacterial cells?
    Lyse and Kill them.
  290. How does lytic bacteriophages lyse and kill the infected bacterial cells?
    By the lytic cycle
  291. What are the steps to the lytic cycle?
    1, Bacteriophage attached to bacterium, 2, penetration of phage nucleic acid into cell, 3, synthesis of phage nucleic acid and protein coat, 4, assembly of mature phage particles, 5,lysis and release of progeny phage.
  292. What is the typical amount of new phages that a bacterium can produced after it is lysed?
  293. What is the receptor for the T4 phage?
  294. Where is lipopolysacharide usually found?
    Gram negative bacterial cell wall
  295. What is the purpose of the fibral legs at the bottom of the T4 phage?
    To draw the phage in closer to the target so that the LPS receptors can latch onto the host and begin injecting it with viral nucleic acid via the tube.
  296. The binding of the T4 phage to the bacterial cell wall via LPS is called what?
  297. The "drilling and injection" of viral nucleic acid of the t4 phage is called what?
  298. Phage morphogenisis occurs in a __________
    Stepwise progression
  299. What are the 8 steps of phage morpogenesis?
    preferential mRNA, DNA synthesis, protein synthesis, incomplete head assembly, DNA packaging, tail addition, matuartion and lysis
  300. What is the latent period for phage morphoenesis?
    When the phage information makes its way to the bacteria for adsorption and penetration
  301. What is the eclipse period for phage morphoenesis?
    The time of phage penetration to the time of the production of new phage particles produced inside the cell
  302. What are the two lifestyles a temperate phage can go through?
    Lytic and lysogenic
  303. What is the lysogenic lifestyle in temperate phage?
    After penetration growth stops. the viral genome incorporates itself into the bacterial genome
  304. What is the benefit of the lysogenic lifestyle for a phage?
    Instead of being harmed outside the bacteria, it hides out in the bacterial genome and replicates only when the cell normally replicates, the lysogenic lifestyle is reversible
  305. Which bacteriophage lifestyle is reversible?
    The lysogenic one
  306. What lifestyle does the phage go to if it is reversing from the lysogenic one?
  307. Why is it a great benefit that the lysogenic lifestyle is reversible?
    Because if the host cell becomes unfavorable or dangerous for the phage, it can swith back to the lytic lifestyle instead of dying (survival tactic)
  308. What kind of bacteriophage is a lambda bacteriophage?
  309. What is the basic description (shape) of the bacteriophage lambda?
    Icosohedral head, a tail and fiber at the bottom
  310. What is the difference between the temperate lifestyle in the t4 and lambda bacteriophages?
    Instead of the DNA staying linear like the T4, lambda will actually circulize the DNA.
  311. How does lambda circurlize the DNA
    using COS sites
  312. How do the COS sites work?
    The DNA strands have sticky partial COS sites at each end to the strands. When the strands overlap, it is found that the ssDNA are reverse and complimentary to one another making it possible for the DNA to anneal.
  313. What is so different about the DNA sequencing for the COS sties?
    High amount Of G (guansine) and C (cytosine)
  314. how many hydrogen bonds are in C-G pairs?
  315. how many hydrogen bonds are in A-T parirs?
  316. why are G-C pairs more favored than A-T pairs?
    More hydrogen bonding= stronger
  317. What seals the gaps and the lambda COS sites?
  318. When does lambda have to make a decision about taking the lytic and lsyogenic route?
    when the DNA becomes circular
  319. What are the 4 promoters that the lambda phage has?
    P-L, P-r, P-re, P-rm
  320. Which lambda promoters are for lysis?
    P-L and P-r
  321. Which lambda promoters are for regulation?
    P-re & R-rm
  322. How is it determined whether a lambda will be lysogenic or lytic?
    By which promoter (P-re or P-r) becomes active first.
  323. in the lambda, what kind of protein is the C1 protein?
    DNA binding protein
  324. What does the C1 protein in lambda do?
    represses P-l and P-r (causes lysogenic lifestyle)
  325. What does the CRO protein in lambda do?
    Inhibits the C1 protein (anti-repressor)
  326. If the CRO protein is activated what lifestyle will the lambda take?
    lytic lifestyle
  327. If the C1 protein is activated what lifestyle will the lambda take?
    Lysogenic lifestyle
  328. Whats theta replication?
    in the lambda lytic cycle, after dna circularization in splits into two (bidirectionia)
  329. What is rolling circle replication?
    When an empty phage head comes and binds to a COS site, then a TER cleaves the COS site leaving a ssDNA tail
  330. What is a ter?
    Something that cleaves the COS site leaving a ssDNA tail
  331. what is ssDNA?
    Single stranded DNA
  332. When will the phage head stop getting DNA in the rolling circle replication in lambda?
    when it gets to the next COS site
  333. What is between the COS sites in the lambda rolling circle replication?
    A fullsized genome
  334. why is phage circulation important in DNA
    to make sure it produces
  335. What are the three factors that are required for a lambda phage to undergo the process of lysogeny?
    attP site, attB site and Int
  336. What is the attP site?
    attachment phage site
  337. what is the attB site?
    attachment bacterium on choromsome
  338. what is the Int ?
    an enzyme theat is rocombinase, its expression depends on C1, (Phage "integrase")
  339. Lysogenic integration requires _______ recombinase.
  340. Do attP and attB have similar sequences or the same, or different?
  341. Why is the int enzyme important at hybrid attP and attB sites?
    int is able to detect which is which and can recombine the two to produce an intergrate lysogen
  342. a continuous expression of C1 maintains a _________ state.
  343. What happens if a lysogenized cell is infected by another lambda phage and chooses a lytic lifestyle?
    the existing lambda will be destroyed along with the cell.
  344. What can save a lysogenic phage from a lysogenic attack by a second phage?
    superinfection immunity
  345. What protects a lysogenized phage from lyogenic attack by a second phage?
  346. how does the C1 protect a lysogenized phage from lyogenic attack by a second phage?
    blocking the replication because C1 itself is a pre-existing repressor.
  347. The excision of lambda is the opposite of________.
  348. What is the process of the excision of lambda?
    It is a dis-intergration of lambda from the chromosome, a recombinase (Xis) recognizes and excies the attb/attp sites
  349. adverse environmental conditions exert __________ on bacterial populations.
    selective pressures
  350. What is the selective advantage?
    preferential outgroeth of selected clones
  351. when bacterium survies due to acquisition of a favorable, adaptive mutation what does it avoid?
  352. What is the basis for changes that must occur for bacteria to respond to selective pressure?
    an arise from alteration in the genetic information encoded by the cell.
  353. what kinds of alterations must occur for bacteria to respond to selective pressure?
    • random changes
    • non-random (programmed) changes
    • Acquisition of new external information (transmission)
  354. When a complementmediated antibody undergoes phase variation, does it produce an antigen?
  355. When a complementmediated antibody undergoes antigenic variation, does it produce an antigen?
  356. For bacteria, which was does information flow?
    gene to mRNA to protein
  357. What starts that information flow from the gene to the protein?
    The promoter (-35 and - 10 sequences)
  358. Where does transcription initiaion start?
    ribosomal binding site
  359. whats is the initiation codon at the start of?
  360. What are the 3 different stop codons?
  361. Random genetic variation is..
    alteration (mutations) in the genome of a single bacterium
  362. Non random genetic variation is...
    (programmed) alterations in the genome of a single bacterium
  363. transmission (genetic variation) is ...?
    transmission of genetic material b/t bacteria that introduces new information into the cell.
  364. Mutations are heritable alteration in the ___________ of the DNA
    nucleotide sequence
  365. What may change the protein's amino acid sequence of the RNA encoded by a gene
  366. What can mutations do only in RARE cases?
    give a cell selective advantage in certain environmental conditions
  367. Mutations may result because of?....
    errors made during DNA synthesis or by an insult to the DNA (chemicals, radiations, etc.)
  368. What is semi-conservative replication?
    one original strand of the DNA is conserved in each daughter cell
  369. What is the rate of mutation in semi-conservative replication?
    10-7 - 10-11
  370. What explains why cells replicate their DNA with such high fidelity?
    semi conservative replication
  371. why does the semi-conservative replication have repair mechanisms?
    to correct infrequent errors made during replication
  372. ________ mutations can change protein sequences
  373. streptomycin binds to the amino acids _____ and _____ of S12
    42 and 87 (lysine 42, lysine 87)
  374. What does a single nucleotide change in the codon at amino acid position 42 in the S12 subunit changes a lysine to ________.
  375. what removes the streptomycin binding site
  376. what is resistant to the bactericidal effects of streptomycin
  377. What are targets for the immune system to produce protective antibodies?
    molecules exposed on the outer surface of bacteria
  378. how can a bacterium avoid production of protective antibodies?
    dont express the molecule or express a differnent form of the molecule
  379. How many opa-encoding genes are there in Neisseria Gonorrhoeae
    11 (opaA...opaB..etc)
  380. How many different antigenic variants of Opa can be expressed by neisseria?
  381. How does neissera gonorrhoeae elude the immune system?
    phase and antigenic variation of Opa proteins
  382. phase and antigenic variation of opa proteins depends upon what?
    alterations in the numbers of CTCTTrepeats in the signal peptide encoding regiona of the gene.
  383. What is the signal peptide?
    regiona at the N-terminus of a polypeptide that mediates transport of protein to the outer rmemberane.
  384. A correct reading frame leads to ..?
    Opa epression
  385. A protein is truncated when?
    loss of one TCTTC sequence
  386. What are the expressions that salmonella flagelum can have?
    H1 flagella or H2 flagella
  387. Salmonella flagellum is ________ distinct.
  388. Antibodies to H1 do not react with _____.
  389. Antibodies to H2 do not react with _____.
  390. Mechanism of the invertible Hin region?
    Hin catalyzed, site specific inversion, turned into Ph2, then inverted and repeated.
  391. What are the four mechanism of genetic transmission?
    • transformation
    • transduction
    • conjugation
    • Transposition
  392. Transformation is?
    uptake of naked DNA
  393. Transduction is?
    transfer involves a bacteriophage
  394. Conjugation is?
    cell-to-cell contact required
  395. transposition is?
    mobile genetic elements
  396. in a lytic infection, a fragment of ______ is aberrantly packaged into an empty phage particle
    bacterial DNA
  397. Do plasmids usually encode housekeeping genes?
  398. Why are plasmids typically dispensable to the host under most conditions?
    because they do not usually encode "housekeeping genes"
  399. Some plasmids have _____ fucntion in the cell.
    no identified
  400. Cryptic plasmids are?
    plasmids that have no identified function in the cell.
  401. Most plasmids encode _______.
  402. Most plasmids encode function which may provide a ________ to the cell in certain conditions.
    selective advantage
  403. Multiple antibiotic resistance may be encoded on a _______ plasmid.
  404. conjugation requires cell-to-cell contact which is mediated by the ___________.
    conjugation pilus
  405. what are transposons?
    Elements that can mobilize from one site to another site in a chromosome or other DNA.
  406. Transposition does not require ______ between the transposon and the site of insertion.
    homologous recombination
  407. When do transposons move between bacterial cells?
    When the DNA where it resides is introduced into a new host call by (conjugal plasmids, bacteriophages, transformation, etc.)
  408. Transposons can cause ______ in genes or can ______ into a cell which provide a selective advantage.
    • mutations
    • introduce genes
  409. What are the 7 characteristics of Ideal antimicrobial agents?
    • •Only destroys the offending microbe
    • •Targets microbial processes that are not present in the host
    • •Have limited or no toxicity to the host
    • •Long half-life of the drug
    • •Both oral and intravenous formulation
    • •Have little effect on normal host flora
    • •Not be susceptible to microbial resistance mechanisms
  410. Antibiotics are only effective against...
  411. Many common classes of antibiotics are based on their ...
    mechanism of action.
  412. What are five cell wall active agents?
    • •Penicillins
    • •Cephalosporins
    • •Monobactams
    • •Carbepenems
    • •Glycopeptides
  413. What are the three kinds of protein synthesis inhibitors?
    • 50 s ribosome inhibitor
    • 30 s ribosome inhibitor
    • DNA dependent/RNA polymerase inhibition
  414. What are the five kinds of 50s ribosomes inhibitors?
    • –Erythromycin
    • –Clindamycin
    • –Chloramphenicol
    • –Streptogramins
    • –Oxazolidinones
  415. What are the two kinds of 30s ribosome inhibtors?
    • –Aminoglycosides
    • –Tetracyclines
  416. What is the DNA-dependant/RNA polymerase inhibitor?
  417. What two things are used for DNA synthesis and Maintenance?
    • Sulfonamides and trimethoprim
    • Quinolones
  418. through the antibiotic classification, what are the extra cell wall active agents?
    • –Lipopetides
    • –Lipoglycopeptides
  419. through the antibiotic classifcation, what are the added 50s ribosome inhibtors?
    • •Macrolides
    • •Ketolides
    • •Lincomycins
  420. through antibiotic classifcations, what is the added inhibitor for 30 s ribosome?
  421. What is a unique microbial target?
    cell wall
  422. How do bacteria make cell walls?
    peptidoglycan, repeating structure of N-acetylmuramic acid and N-acetylglucosamine
  423. gram positive bacteria stain ______.
    blue/deep dark purple
  424. gram negative bacteria stain ______
  425. We knew penicillins would work in fighting bacteria because?
    when there was mould in a plate, bacteria would not grow around it , mould = penicillin strain
  426. Why does penicillin work?
    transpeptidase reaction
  427. binding the penicillin to the vtranspeptidase results in what?
    acylation of the transpeptidase, causing irreversible inhibition of transpeptidase
  428. The 3-d structure of penicillin looks like________.
  429. Why doesnt penicillin kill all bacteria?
    • •Penicillin doesn’t bind to all penicillin binding proteins
    • •Bacteriahave ways of destroying penicillin
  430. Beta-lactamases hydrolyze the beta-lactam ring and render _______ ineffective.
  431. Humans can fight against ________ to make peniciillin effective.
  432. Can you ever sterilize the host?
  433. _______ are always smarter than we are.
    the bugs
  434. What is the vancomycin mechanism?
    hydrogen bonds with the d-alanine-D-alanine structuree and covers the site of the action of a tranpeptidase so ir can no longer work by cross linking.
  435. Beta-lactamases do not ________ vancomycin
  436. do all bacteria use D-alanine-D-alanine on their cell wall precursors?
  437. If bacteria exchanges genes to synthesize a diff. type of cell wall precursor (no a-ala-d-ala) then it would be ......
    vancomycin resistant
  438. Do protein synthesis inhibitors target human ribosomes?
  439. protein synthesis inhibition target _________.
    bacterial ribosomes
  440. How do you become resistant to protein syntheis inhibtors?
    • alter ribosomal binding site
    • pump antibiotoics
  441. Quinolones alter DNA gyrase-responsible for ...
    folding and unfolding the DNA
  442. What are the 2 enzymes that quinolones target?
    • DNA gyrase (gyrA and gyrB)
    • Topoisomerase IV (parC and parE)
  443. What are structural analogs of PABA that competitively inhibit dihydropteroate synthase.
  444. What completely inhibits dihydropteroate synthase
  445. Organisms sensitive to the
    sulfonamides require ___________ in order to form dihydrofolic acid which is essential in the
    production of nucleic acids.
    extracellular PABA
  446. Mammalian cells (and some bacteria) lack the enzymes required for folate synthesis and depend upon...
    exogenous sources of folate
  447. Why are mammalian cells and some bacteria not susceptible to sulfonamides?
    they lack the enzymes required for folate synthesis and depend upon exogenous sources of folate
  448. Antimicrobial is just one example of antibiotics that...
    can kill or inhibit bacteria
  449. What are the 4 control of infectious disease agents?
    • public sanitation
    • sterilization and disinfection procedures
    • chemotherapeutic agents
    • bodies defense mechanisms
  450. Sterilization
    total destruction of all microbes
  451. Disinfection
    the destruction and removal of most pathogenic microbes from inanimate objects. All microbes are not removed
  452. The leftover microbes of disinfection are...
    nonpathogens and spores of pathogens
  453. Disnfectant
    the chemical agent used to disinfect
  454. Bacteriocidal
    an agent that kills bacteria
  455. Bacteriostatic
    An agent that inhibits bacterial growth
  456. Antiseptic
    chemicals with low human toxicity that destroy microorganisms capable of causing contamination or disease
  457. What are the 8 factors affecting sterilization/disinfetion action?
    • time
    • temperature
    • pH
    • number of microorganisms
    • types of microorganisms
    • presence of extraneous matter
    • proper exposure
    • concentration of disinfectant or sterilant
  458. What are the three methods of physical control?
    • heat
    • radiation
    • filtration
  459. High temperature inactive proteins and nucleic acids by..?
    breaking their hydrogen bonds
  460. Radiation causes chemical changes to...
    the nitrogenous bases of nucleic acids
  461. Filtration
    physical removal of organisms from the solution that is filtered
  462. What is the most widely used method ofr microbial control?
  463. what are the heat sterilization parameters?
    temperature, duration and humidity
  464. Decimal reduction time or D value measures?
    an organism's heat resistance
  465. What are the two heat sterility tests?
    • heat sensitive tape
    • biological monitor
  466. heat sensitive tape
    tape impregnated with chemicals that change color when exposed to a critical temperature
  467. Biological monitor?
    spore strips of clostridium or bacillus
  468. What are the 4 main heat treament procedures?
    • dry heat
    • moist heat
    • boiling water
    • pasteurization
  469. Dry heat is...
    generated by an oven
  470. Dry heat condition...
    160 C - two hours to kill spores
  471. dry heat usage..
    sterilization of laboratory glassware
  472. dry heat disadvantage...
    high temperature, chars organic materials
  473. moist heat is...
    generated by an autoclave (industrial pressure cooker)
  474. moist heat condition..
    121 C for 15 minutes, @ 15 psi - kills spores
  475. moist heat usage...
    sterilization of microbiological media, glassware and commercial canning
  476. moist heat disadvantage...
    expensice equipment
  477. boilig water is..
    a water bath or chamber
  478. boiling water condition
    100 C for 30 minutes - kill all non-spore forming microorganisms
  479. boiling water usage (2 places)
    • hospitals - disinfect bedding/clothing of patients
    • home - boil unsafe drinking water, disinfect baby items (food prep and utensils)
  480. boiling water disadvantage?
    items easily recontaminated when removed from water
  481. pasteurization is....
    process of using mild heat to kill pathogens while reserving the quality and flavor of food
  482. pasteurization condition
    62 to 66 C, 30 minutes, quick cool (kill coxiella burnetti)
  483. pasteurization usage
    destruction of pathogens in milk, beer and wine --- increases shelf life
  484. flash pasteurization..
    newer technique
  485. flash pasterization condition...
    71.7 C, 15 seconds, quick cool
  486. radiation
    emission and propagation of energy through space or through a substance in the form of waves
  487. What are the two form of waves in radiation?
    • ultraviolet (UV) light (non ionizing)
    • Ionizing radiation
  488. What is the range for UV light?
    100-400 nm wavelength
  489. what are the two kinds of UV light?
    • Bacteriocidal wavelength
    • Germicidal lamp (mercury vapor lamp)
  490. What is the wavelength range of the bacteriocidal wavelength?
    250-270 nm
  491. bacteriocidal wavelength...
    DNA absorbs UV light which induces a rearrangement in hydrogen bonding of the DNA strand. (copying errors - increase probability of lethal mutation)
  492. At what wavelength does a germicidal lamp generate a radiation?
    254 nm
  493. germicial lamp usage...
    disinfection. lamps placed in air ducts or directly over surface. UV lamps put in air supply of operating rooms, food preparation areas, nursing homes and nurseries.
  494. germicial lamp effectiveness
    reduces the concentration of air-borne microbes by 99%
  495. germicial lamp disadvantage
    limited use (UV unsafe)
  496. Ionizing radiation...
    • shorter wavelength than UV
    • shorter wavelentgh means increased energy
  497. ionization forms...
    primariliy free hydroxyl radicals which react with cellular proteins and nucleic acids, inducing chemical alterations that are cidal
  498. ionizing radiation usage
    sterililzing med prodcuts and tissues (bones skin, tissues, heart valves)
  499. ionizing radiation advantage..
    • speed
    • high penetration power (ability to penetratea objects for sterilization)
  500. ionizing radiation disadvantage
    radiaion exposure
  501. Filtration
    Sterilization technique for removing microbes, not destroying them. Fluid (air or liquid) is strained through a layer of material with openings (pore sizes) large enough for the fluid to pass through but too small for microorganisms.
  502. Filter membranes
    cellulose acetate, polycarbonate, variety of plastics (Teflon or nylon)
  503. for filters 0.22 mm pore size removes...
    all bacteria
  504. for filters 0.025 mm pore size removes...
    all viruses
  505. Liquid filtration
    used to sterilize liquids that cannot withstand heat –

    (serum, blood products, vaccines, antibiotics, IV fluids and enzymes) (Water purification)
  506. Air filtration
    • HEPA (high efficiency particulate air filters) are used in
    • air ducts to critically clean areas
  507. HEPA filter –
    tightly woven fiberglass medium which remove particles as small as 0.3mmwith 99.9% efficiency
  508. HEPA filter usuage..
    HEPA filters are installed in air supply systems to operating rooms, nurseries, intensive care units and biohazard hoods.
  509. What are the ten methods of chemical control?
    • Alcohols
    • Halogens
    • Aldehydes
    • Heavymetals
    • Gases
    • Surfaceactive agents (cationic detergents)
    • Phenols
    • Oxidizing agents
  510. Ethyl alcohol and Isopropyl alcohol are effective
    antiseptics when applied....
    as 70-80% aqueous solutions
  511. what is alcohols mode of action
    alcohols precipitate proteins and solubilize lipids present in the cell walls and cell membranes of bacteria
  512. alcohol usage
    human skin antiseptic
  513. alcohol effectiveness
    kill vegetative cells but are not sporicidal
  514. Iodine
    effective antiseptic when solubilized in 70% ethyl alcohol (tincture)
  515. Iodine mode of action
    inactivates proteins and organic molecules by reacting with hydroxyl groups
  516. Iodophors
    iodines complexed with soap
  517. Iodophors usage
    preoperative skin disinfectant
  518. iodophors advantage
    soluble in water and gradually releases iodine
  519. iodophors disadvantages
    not as effective as tincture
  520. Chlorine mode of action
    oxidizes sulfhydral groups of cell proteins
  521. Clorox
    common household disinfectant contains 5.25% sodium hypochlorite
  522. clorox usage
    sanitize toilets, dishes, food processing equipment, additive to swimming pools
  523. formaldehyde and glutraldhyde similarity?
    same mechanism to kill microbes
  524. formaldehyde and glutraldhyde mode of action
    both alkylating agents subsititute alkyl groups for the H atoms of reactive groups of enzymes nucelic acids and proteins
  525. formaldehyde (gas) usuage
  526. formaldehyde (disadvantage)
    noxious vapors, irritates tissues
  527. formaldehyde (solution) formalin usage
    tissue fixative, inactivator of vaccines, embalming fluid
  528. formaldehyde (solution) formalin disadventage
    tissue irritant
  529. glutaraldehyde solution (usage)
    effective cold sterilizing agent (sterilization of dental equipment)
  530. glutaraldehyde solution disadventage
    irritates tissues, mildy disagreeable odor
  531. CU, HG and AG mode of action
    heavy metals toxicity is due to their ability to combine with active chemical (sulfhydral)groups on proteins
  532. Copper sulfate usuage
    • algaecide, additive to marine bottom paints – inhibits
    • attachment of mussels and barnacles
  533. Mercurials usage
    additive to ointments and solutions used in the topical treatment of skin infections
  534. mercurial disadvantage
    toxicity, allergic reactions, and neutralization by organic matter
  535. Silver nitrate
    1% solution of AgNO3 was used as eye drops for newborn infants to prevent infections
  536. Silver sulfadiazine
    additive to ointments used to prevent infections in burn patients
  537. Ethylene oxide
    bactericidal, fungicidal and sporicidal (12 hours, 70°C – kills spores)
  538. Ethylene oxide usage
    sterilizing agents for plastics – petri dishes, tubes, pipets, syringes and catheters
  539. ethylene oxide advantage
    ability to sterilize at moderate temperatures with no moisture
  540. Quaternary Ammonium Compounds (Quats) mode of action
    kills cells by disrupting their cytoplasmic membrane
  541. Quaternary Ammonium Compounds (Quats) usage
    disinfect floors, walls and other inanimate objects. Also used for preparing the vagina and other sensitive mucous membrane structures for surgery.
  542. Quaternary Ammonium Compounds (Quats) advantage
    odorless, colorless, tasteless, inexpensive, non-toxic to mammalian tissue, soluble in water, and active in low concentrations
  543. Quaternary Ammonium Compounds (Quats) disadvantage
    readily inactivated by organic or inorganic substances
  544. Phenols mode of action
    denature proteins, and disrupt cell membranes
  545. phenols advantage
    reasonable cost, compatibility with detergents, resistance to inactivation by organic matter
  546. Lysol
    79% ethyl alcohol and o-phenylphenol
  547. Hexachlorophene – (effectively kills staphylococci) usage
    1960’s as an antiseptic for bathing newborns
  548. Hexachlorophene disadvantage
    absorption through skin linked to brain damage in infants
  549. Hexachlorophene usuage today
    • prescription only
    • 3% hexachlorophene + soap = antiseptic skin
    • detergent = cleaning product
    • lotion = (Hexagerm/pHisoHex)
  550. Hydrogen peroxide
    bactericidal or sporicidal dependent on concentration: 3-6% kills bacteria, 10-25% kills spores
  551. Hydrogen peroxide modes of action
    oxidizing agent that inactivates essential protein structures
  552. Hydrogen Peroxide usage
    a 3% solution is used to cleanse wounds, and disinfect plastic implants, contact lenses and surgical prostheses
  553. hydrogen peroxide advantage
    non-irritating to tissues