Quiz Chapter I : THE SCIENCE OF MICROBIOLOGY __________________________________________________
Mutualism is a mutually beneficial relationship where all the contributing organisms are benefited. Mutualism is also called symbiosis. Lichens - a mutualistic association between fungus fungus and algae algae or cyanob cyanobact acteri eria a (blue(bluegreen algae) VIRUSES are parasites. They require a host cell to multiply multiply. However, However, they belong to the kingdom Prokarya, just like bacteria. Eukaryotic microorganism include algae, protozoa, fung fungii and and slim slime e mold molds. s. They They belo belong ng to the the kingdom Eukarya.
Yeast is a unicellular fungus. Some DEFECT DEFECTIVE IVE VIRUSES VIRUSES such such as, Hepatit Hepatitis is D virus (HDV) require the help of HELPER VIRUSES like Hepatitis B virus (HBV) to replicate in the host cell.
Other Other examp examples les of helper helper viruse viruses s includ include e Adeno associated virus (AAV). VIRIODS VIRIODS are also defect defective ive viruse viruses s in that that they they require the host cell’s protein synthetic machinery for duplication. Viroids consist of covalently closed single single strande stranded d RNA withou withoutt a capsi capsid d coatin coating. g. Howe Howeve verr thei theirr genon genone e does does not not code code for for any any protein synthetic gene.
PRIONS PRIONS are are prote proteina inaceo ceous us partic particles les of an infective nature. They LACK a nucleic acid component. They are encoded by the host cell’s chromosomal DNA, Creu Creutz tzfe feld ldt-Ja t-Jaco cob b dise diseas ase e (CJD (CJD), ), Bovi Bovine ne spongiform encephalopathy (BSE), Scrapie in shee sheep, p, Kuru uru are are all all dise diseas ases es caus caused ed by Prio Prions ns.. Thes These e are are dise diseas ases es of the the cent centra rall nerv nervou ous s syst system em (CNS) CNS) wher where e the host ost encoded sialoglycoprotein is converted into a PROTEASE-resistant PROTEASE-resistant form. The The nucl nucleic eic acid acid of prok prokar aryo yote tes s is call called ed NUCLEO NUCLEOID. ID. Nucleo Nucleoids ids are are NOT bound by a nuclear membrane.
EXAM Preparation
page 1 of 12
Medical Microbiology: Jawetz
Intra cellular organelles organelles are not membrane membrane bound in prokaryotes as in i n eukaryotes. Mycoplasmas, Chlamydia and Rickettsiae are all PARASITIC ARASITIC PROKARY PROKARYOTES. OTES. They are intracellul intracellular ar parasites which absolutely require the metabolic enviro environmen nmentt provide provided d by the host. They lack lack a cell wall.
Myco Mycopl plas asma mas s are are the the only only prok prokar aryo yote tes s capabl capable e of synthe synthesis sising ing choles cholestr trol. ol. Others Others assimilate it from the host cell. QUORUM SENSING is a form of inter cellular communication. The cells produce diffusable signaling molecules termed PHEROMONES or AUTO AUTO INDU INDUCE CERS RS that that allo allow w the the cell cell to its its poupulation density. CHLO HLOROPLAS LASTS and MITO ITOCHON HONDRIA are eukaryotic eukaryotic organelles organelles which have evolved evolved from prokaryotic (BACTERIAL) ENDOSYMBIONTS.
ARCHAEBACTERIA are a distinct phylogenetic domain from PROKARYOTES and EUKARYOTES. They have a more pre dated ancestry. As INTRONS, intervening DNA sequences, are common to both archae haebacteria and eukary eukaryote otes, s, it is reason reasoned ed that that eukary eukaryoti otic c nucleus may have arisen from an archaebacterial ancestor. Blue Blue green green algae algae are are called called CYANO CYANOBA BACTE CTERIA RIA.. The They y are are prok prokar aryo yotic tic unlik unlike e the the TRUE TRUE ALGA ALGAE E whic which h are are clas classi sifi fied ed as euka eukaryo ryote tes. s. Both Both are are capa capable ble of prod produc ucin ing g oxyg oxygen en as a prod produc uctt of photosynthesis.
Fungi and Protozo Protozoa a have a HETEROTRO HETEROTROPIC PIC mode of nutrition, Their energy demands are met by organic compounds. COENOC COEN OCYT YTIC IC refer efers s to a mult multin inuc ucle leat ate e struct structur ure e as seen seen in plasmo plasmodiu dium m of SLIME SLIME MOLDS and some FUNGI.
Quiz Chapter 2: CELL STRUCTURE __________________________________________________ RESOLUTION is the minimum distance by which two point sources of light, or simply two objects, must be separated for them to be distinguished as two separate ones. The resolution of human eye is 200 micrometer.
EXAM Preparation
page 2 of 12
Medical Microbiology: Jawetz
DARK FIELD MICROSCOPY is used to view Treponema pallidum whose diameter is less than 0.2 um.
PHASE CONTRAST MICROSCOPE is used to study internal structures in LIVING cells. Other types of microscopy use killed and stained preparations.
RESOLVING POWER of a microscope is half the wavelength of the light source being used. The wavelength (λ) of visible yellow light used in an optical microscope is 400 nm (0.4 um). So, the resolving power is 200 nm (0.2 um).
NUCLEOLUS is a structure within the eukaryotic nucleus which is rich in RNA and is a site for ribosomal RNA synthesis.
With a MAGNIFICATION of 1000 X (read fold) provided by the use of a 10 X eye piece and 100 X objective lens, minute objects like bacterial cells separated by 0.2 um can be viewed clearly under a microscope.
The protein sorting machinery of a eukaryotic cell consists of the TRANS GOLGI NETWORK. It comprises the ENDOPLASMIC RETICULUM and GOLGI APPARATUS. It is involved in protein synthesis, chemical modificatins and trafficking to appropriate subcellular locations.
Electron microscopes offer a superior resolution due to the shorter wavelength of electron beams. Transmission Electron Microscopes (TEM) have a resolution of 0.001 um. They are used to study viruses.
Scanning Electron Microscopes are used to study the 3-Dimensional Surface Topography of objects, such as the surface of biofilm communities on infected catheters. SEM have a lower resolution than TEM.
MITOCHONDRIA are the site for respiratory ELECTRON TRANSPORT SYSTEM. PLASTIDS include chloroplasts and mitochondria. They are of endosymbiotic origin and contain their own DNA for protein and ribosomal RNA synthesis. Fungal cell wall containsthe polymer CHITIN. Microtubules are composed of a protein called TUBULIN.
SHADOW CASTING is an important technique in electron microscopy to enhance the contrast and visibility of the object being studies. It involves spraying a thin film of heavy metal such as platinum on the specimen before exposing it to an electron beam.
The arrangement of microtubules in cilia and flagella is called “9+2” arrangement.
NEGATIVE STAINING involves coating ultra thin sections with heavy metals such as uranyl acetate or phospho tungstic acid. It enhances the surface contrast of the specimen in electron microscopy. It is also used to describe a procedure where the background is stained leaving the cells colourless.
PHYCOBILINS, BACTERIOCHLOROPHYLLS and CAROTENOIDS are all photosynthetic pigments.
In PHOTOSYNTHETIC BACTERIA the photosynthetic machinery is located on the cytoplasmic membrane. In cyanobacteria they are known as THYLAKOIDS.
STORAGE GRANULES in bacteria are used to store reserve food material. These include poly beta hydroxy butyrate granules, sulfur granules, polyphosphate granules, VOLUTIN / METACHROMATIC granules seen in corynebacteria .
PEPTIDOGLYCAN is a component of bacterial cell wall.
Quiz
EXAM Preparation
page 3 of
12 Medical Microbiology: Jawetz
Forma of CHEMOTAXIS include PHOTOTAXIS (towards light), AEROTAXIS (towards optimal oxygen concentration) and ELECTRON ACCEPTOR TAXIS (towards alternative electron acceptor). Alterations in the transcriptional specificity of RNA polymerases is effected by attachment of SIGMA FACTORS.
The protein subunitS of pili are PILINS.
__________________________________________________ Cytoplasmic membrane is SEMI PERMEABLE. IONOPHORES are compounds that act on the cytoplasmic membrane by forming pores. The discharge the membrane potential and are thus lethal to all cells. Valinomycin mediates the passage of potassium ions. L-forms are bacterial cells which have lost their cell wall incompletely due to antibiotic treatment. However, thy are able to resume cell wall synthesis under appropriate conditions.
CAPSULE, glycocalyx and SLIME LAYER are names for extracellular coat surrounding the cell wall. Based on flagellar arrangement bacteria are classified as MONOTRICHOUS-single polar flagellum, LOPOTRICHOUS-multiple polar flagella, PERITRICHOUS-flagella distributed all over the body. The protein subunits that form flagella are FLAGELLIN. They can be antigenic as in Hantigen of Salmonella typhi. SENSORY TRANSDUCTION is the change in cell behaviour in response to environment. Bacteria reproduce by BINARY FISSION. Cocci in chains -- STREPTOCOCCI, cocci in pairs PNEUMOCOCCI,
PALISADE arrangement is seen in corynebacteria.
Quiz Chapter 3.: Bacterial classification _____________________________________________ The formal ranks used in the taxonomy of bacteria are: Species
vision
Exam Preparation 13 Medical Microbiology: Jawetz
page 4 of
Exam Preparation
Quiz
8 Medical Microbiology: Jawetz
Chapter 4.: Th Growth, Survival and Death of microorganisms. _____________________________________________ STANDARD CURVE is a quantitative research tool. It is a method used for plotting assay data to determine the concentration of a substance or cell numbers. GROWTH RATE is the rate at which cells are producing more cells. It is the product of the growth rate constant (k) and the biomass concentration (B). MEAN GENERATION TIME is the average time taken for a bacterial population to double in number or biomass. The SIX PHASES IN THE MICROBIAL GROWTH CURVE ARE: LAG PHASE ---> ACCELERATION PHASE ---> LOG PHASE -----> RETARDATION PHASE -----> STATIONARY PHASE ------> PHASE OF DECLINE. STERILIZATION is the process organisms in a preparation.
page 5 of
of
killing
all
BACTERIOSTATIC agents inhibit bacterial multiplication but DO NOT necessarily kill the microorganism. DISINFECTANTS are used to kill microbes on inanimate surfaces. Eg. Phenol, Alcohol, formaldehyde ANTISEPTICS are used to inhibit the growth of microbes in living tissue. Eg. Chlorhexidine, CETRIMIDE, Benzalkonium chloride. ANTIBIOTICS are naturally occurring or synthetic ORGANIC COMPOUNDS which SELECTIVELY DESTROY bacteria at a given concentration.
RADIATIONS act by damaging DNA. Eg. Ionizing radiations, Ultraviolet light. They are used as sterilizing agents. PROTEIN DENATURATION is the disruption of teritary structure of protein. AUTOCLAVING uses steam under pressure to kill bacterial cells. It operates at temperatures of 121 0 C for 15 minutes to destroy bacteria.
HOT AIR OVEN is used to sterilize materials that must reman dry. It applies a temperature of 160 0 C for 1 hour.
ANTIMICROBIAL INDEX is the ratio of inhibitor concentration to concentration of the substance reversing the inhibition. A very high index means that the enzyme has a higher affinity for its natural substrate. PENICILLIN inhibits cell wall synthesis. OXIDISING AGENTS form disulfide between adjoining sulfhydryl groups. sodium hypochlorite.
linkages Eg. O2-,
HYDROGEN PEROXIDE is bactericidal, virucidal, fungicidal and sporicidal. IODOPHORES are complexes of iodine and a solubilizing agent. Eg. Poividon Iodine. Quarternary Ammonium Compounds (QAC) are powerful antiseptics. The are used in preoperative disinfection of skin.
EXAM Preparation
Quiz
page
6 of 8 Medical Microbiology: Jawetx
Chapter 5.: Cultivation of Microorganisms ____________________________________________ MITOCHONDRIA are the power house of a cell. The PHOSPHODIESTER chemical energy.
BOND
in
ATP
stores
ASSIMILATORY nitrogen metabolism--NITROGEN FIXATION--end product NH4+ (ammonium).
Nitrogen Fixation is inhibited by Oxygen. N2 + 6 e- + (ammonium ion)
8H+
--->
2 NH4+
DISSIMILATORY nitrogen metabolism--DENITIFICATION---end product N2 gas.
The chemical energy released from the cleavage of phosphodiester bond is used in the synthesis of ANHYDRIDE BONDS in macromolecules.
NO2+ 6e- + 2H+ ----------> NH4+ + 2 H2O (NITRIFICATION) --- an assimilatory process.
The ELECTRON TRANSPORT CHAIN is involved in the generation of PROTON MOTIVE FORCE.
DEAMINATION is the removal of the amino radical from an amino acid. It is a dissimilatory process.
Proton motive force is an ELECTROCHEMICAL GRADIENT consisting of a difference in ionic charge and a difference in hydrogen ion concentration. A source of energy is required to establish a proton motive force. RESPIRATION involves a series of OXIDATIONREDUCTION (REDOX) reactions with the resultant release of chemical energy which is stored as ATP. Respiration involves oxidation of organic matter using oxygen as electron acceptor. RESPIRATION TRANSPORT.
is
coupled
to
ELECTRON
The ATP formed through FERMENTATION is not coupled to electron transport. MICROBIAL DEATH is the irreversible loss of the ability to reproduce. FERMENTATION is characterised by SUBSTRATE LEVEL PHOSPHORYLATION. The net energy yield from the fermentation of glucose by Embden Meyerhof Pathway is 2 molecules of ATP. O2, SO42- (sulphate) and NO3- (nitrate) are OXIDANTS and can serve as terminal electron acceptors in RESPIRATION. In PHOTOSYNTHESIS both oxidants and reductants are created photochemically using light energy from the sun. AUTOTROPHS do NOT require organic matter for
growth, they use inorganic substrates. HETEROTROPHS require organic matter for growth.
Deamination: Amino acid + Oxygen --> Keto acid + Ammonia (ammonification). Most microorganisms use SULPHATE as sulphur source, reducing it to hydrogen sulphide H 2S. Phosphorous is always inorganic phosphate Pi.
assimilated
as
free
Based on optimal pH requirement microbes can be classified as acidophiles (< 3.0). neutralophiles (6-8), alkalophiles (>10.5). ARRHENIUS PLOT: the velocity of a chemical reaction (log k) is a linear function of the reciprocal of temperature (1/T). OXIDATIVE STRESS can be induced by the products of aerobic metabolism such as hydrogen peroxide [H2O2], superoxide anion [O2-] and hydroxyl radical [OH-]. Organisms requiring high salt concentrations are HALOPHILIC. Organisms requiring high osmotic pressure are OSMOPHILIC. The gelling temperature for agar is 45 0C.
Quiz
ABC Junior High School 12 1234 Main Street Anytown, State 54321
Course Name: Student’s Name:
Teacher’s Name: Trenz Pruca
page 7 of
Quiz
ABC Junior High School
page 8 of
12 1234 Main Street Anytown, State 54321
Lorem ipsum dolor sit amet, consectetur adipiscing elit, set eiusmod tempor incidunt et labore et dolore aliquam? Ut enim ad minim veniam, quis nostrud exerc. Irure dolor in reprehend incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam? Duis aute irure dolor in reprehenderit in voluptate velit esse molestaie cillum? Tia non ob ea soluad incommod quae egen ium improb fugiend. Officia deserunt mollit anim id est laborum Et harumd dereud facilis est er expedit distinct?
Quiz
ABC Junior High School 12 1234 Main Street Anytown, State 54321
Course Name: Student’s Name:
Teacher’s Name: Trenz Pruca
page 9 of
Quiz
ABC Junior High School
page 10 of
12 1234 Main Street Anytown, State 54321
Lorem ipsum dolor sit amet, consectetur adipiscing elit, set eiusmod tempor incidunt et labore et dolore aliquam? Ut enim ad minim veniam, quis nostrud exerc. Irure dolor in reprehend incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam? Duis aute irure dolor in reprehenderit in voluptate velit esse molestaie cillum? Tia non ob ea soluad incommod quae egen ium improb fugiend. Officia deserunt mollit anim id est laborum Et harumd dereud facilis est er expedit distinct?
Quiz
ABC Junior High School 12 1234 Main Street Anytown, State 54321
Course Name: Student’s Name:
Teacher’s Name: Trenz Pruca
page 11 of
Quiz
ABC Junior High School
page 12 of
12 1234 Main Street Anytown, State 54321
Lorem ipsum dolor sit amet, consectetur adipiscing elit, set eiusmod tempor incidunt et labore et dolore aliquam?
Ut enim ad minim veniam, quis nostrud exerc. Irure dolor in reprehend incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam?
Duis aute irure dolor in reprehenderit in voluptate velit esse molestaie cillum?
Tia non ob ea soluad incommod quae egen ium improb fugiend. Officia deserunt mollit anim id est laborum Et harumd dereud facilis est er expedit distinct?
