Microbiology Final EXAM CSCC
What are endospores? How and when do they form?
"cell within a cell" produced by some bacteria in response to stressful conditions, cell inside is highly resistant, Bacillus and Clostridium can do this (very hard to get rid of). Mother cell dies, leaving endospore to be released
What is the Krebs cycle? ATP production?
(2) CC-CoA (Acetyl CoA) --> CO2 + CoA --> 8H+ + 8e- --> 2ADP + 2P --> 2ATP
What is a codon? Anticodon?
- A codon is a sequence of 3 nucleotides in mRNA that encode a specific amino acids AUG : start codon UAA, UAG, UGA: stop codons - Anticodon is a portion of tRNA that recognizes the codon from the mRNA
What are antigens, haptens, and immunogens?
- Antigens - a foreign substance that binds to antibodies and may illicit an immune response - Haptens - illicit an immune response when bound to a carrier molecule, but not by themselves - Immunogens - another name for antigen, foreign substance
Conditions for moist heat sterilization? Effectiveness?
- Boiling: at 100C for 10 mins (does not kill endospores) - Autoclave: uses pressure to raise boiling temperature, 120C at 15 psi for 15 min (sterilizes, kills endospores) - Pasteurization
How were vaccines discovered?
- By the Chinese, would sniff a small pox scab and the person would not get small pox have to pick the perfect scab - By the Europeans, variolation, deposited smallpox scabs directly beneath the skin
What are Candida albicans and Saccharomyces?
- Candida: yeast infection - Saccharomyces: brewers or bakers yeast
What are the primary shapes and arrangements of prokaryotic cells?
- Coccus (round) - Bacillus (rod) - Vibrio (bent rod) - Spirllium - Spirochete Arrangement - single -strepto (chain) - Diplococcus (short chain) - Staphylo (cluster)
What are critical, semi critical, and noncritical instruments? Examples?
- Critical Items: penetrate tissues, ex: Scalpel, needle - Semicritical Items: contact mucous membranes, ex: Endoscope - Noncritical Items: contact unbroken skin, ex: stethoscope
What are the various types of viral genomes?
- DNA (HPV) or RNA (HIV) - Single Stranded or Double Stranded - Simple (HPV) or Segmented (Influenza)
How does the term disease differ from infection?
- Disease: movement of the body away from a state of health (homeostasis) (not all diseases are infectious) - Infection: colonization of the body by microorganisms
What are flagella, fimbriae, and pili
- Flagella: complex protein machine used for motility - Fimbriae: short protein "hairs", used for attachment - Pili: Hollow protein tube, used for material exchange, genetic information
What are trematodes?
- Flukes - small, flat complex bodies (not segmented) - Fluid feeders (blood, parasites) - Clonorchis: Liver Fluke
What diseases are caused by Giarida, Trichomonas, Trypanosoma, Entamoeba, and Plasmodium?
- Giarida: Archaezoans, fatty diarrhea - Trichomonas: Archaezoans, vaginitis - Trypanosoma: sleeping sickness - Entamoeba: bloody diarrhea - Plasmodium: malaria
How do cell walls of Gram (+) and Gram (-) cells differ?
- Gram (+) - is a thick layer of peptidoglycan surrounding a single membrane (one phospholipid bilayer) it stains purple Gram stain - Gram (-) - Thin layer of peptidoglycan sandwiched between an inner and outer membrane (2 phospholipid bilayers), it also contains lipopolysaccharide (LPS) located on the outer leaflet of an outer membrane, it stains Pink Gram Stain
What are Gyrase, Helicase, Polymerase, and Ligase?
- Gyrase: uncoils the DNA (makes it accessible) - Helicase: unwinds/unzips the helix - Polymerase: synthesized the new DNA in a 5' to 3' direction - Ligase: "glues" the fragments together
What precautions can be taken to reduce HAIs?
- Handwashing - PPE - disposable equipment - Aseptic Technique - Isolation - Education
What are antibodies? Structure?
- Large globular glycoproteins that bind to specific antigens - 4 polypeptide chains, 2 heavy chains and 2 light chains held together with covalent disulfide bonds - has two antigen binding sites
What is meant by natural and artificial immunity?
- Natural: comes into your body naturally - Artificially: is injected into your body
What is meant by active and passive immunity?
- Naturally Acquired: Active: enter the body naturally (truly immune) Passive: pass from mother to fetus or to infant via breast milk (temporary protection) - Artificially Acquired: Active: vaccine, body produces antibodies and specialized lymphocytes Passive: performed antibodies introduced by injection, immediate but temporary (antivenom)
What are neutrophils, monocytes, and macrophages?
- Neutrophiles: "first-responders", begin phagocytes immediately, eat themselves to death - Monocytes: differentiate into macrophage, digest with lysozyme, excrete waste so they can keep digesting - Macrophages: come in later, but can continue eating
What are enveloped and non-enveloped viruses? Examples?
- Non-enveloped: "naked virus", HPV - Enveloped: out coat made of phospholipids and has spike proteins, HIV and Influenza
What is the structure of a virus?
- Polyhedral ( six sides) - Helical (cylinder) - Complex (combination of both)
How do prokaryotic and eukaryotic DNA differ?
- Prokaryotic: Circular, closed loops, single chromosome, haploid - Eukaryotic: Linear, multiple chromosomes
What are reservoirs?
- Reservoir: concentrated location of pathogens 1. Humans - carrier/sick 2. Animal - zoonosis (rabies) 3. Non-living - soil, air, water
What are restriction enzymes and ligase enzymes?
- Restriction enzymes read the DNA, and cut the DNA at a specific sequence - Ligase enzymes fuse DNA strange together "glue"
What are siderophores, collagenase and hyaluronidase?
- Siderophores: substances that bind very strongly to host nutrients, pull away iron ex: Yersinia pestis - Collagenase: in connective tissuse, enzyme destroys connective tissue - Hyaluronidase: in connective tissue, enzyme destroy connective tissue
What is meant by the terms sporadic, endemic, epidemic, and pandemic?
- Sporadic : a disease that occurs occasionally in a population - Endemic : a disease that is constantly present in a certain population - Epidemic - a disease acquired by many host in a give area in a short time - pandemic : a epidemic that occurs worldwide
What is microbial antagonism? example?
- Staphyloccus epidermidis: outcompetes Staphyloccus aures - Lactobaccilus acidophilus: creates acid, changes the environmental pH - E. coli: secreted bacteriocins (inhibits growth of other bacteria)
What are the three types of symbiosis?
- Symbiosis: "living together", lives are interconnected with microorganisms - Mutualism: E. Coli, +/+ - Commensalism: C. albicans, +/0 - Parasitism: Y. pestis, +/-
What are cestodes?
- Tapeworms - Flat, not complex Taenia - the worms has an outer layer, cuticle, that humans can not digest - made of proglottid (only gonads) - sexual reproduction (Hermaphrodite)
What is meant by sepsis and toxemia?
- Toxemia - the presence of toxins in the blood - Sepsis - presence of a toxin or pathogenic organism in blood and tissue
What are the three routes of transmission?
- Transmission: process by which pathogen moves from reservoir to host 1. Contact - direct: handshake, intercourse, patient care indirect: doorknob, toys, formites droplet: sneezing, coughing, talking (less than 1 meter) 2. Vehicle - something that can move but isn't alvie ( windborne, waterborne, airborne, urine, blood) 3. Vector - mechanical (fly) vs biological ( mosquito)
What are the steps of T-Cell dependent B-cell activation
- antigen fragments are displayed on cell surface using MHC-2 protein - Phagocyte is now serving as an APC - Appropriate Helper T-cells bind to displayed antigen using T-cell receipt and CD4 protein - APC secretes interleukin to activate Helper T-cell - Selected T-cell secretes interleukin to attract B-cells
What are anticoagulants? How does vermox work?
- antihelminth drug - - blood thinners - Vermox inhibits sugar absorption, worms use our sugar to survive (we are so big this doesn't affect us)
What is adherence?
- binding from pathogen to you 1) Glycocoalyx/ Capsule (S. mutans) 2) M- Protein (S. pyogenes) 3) Fimbriae (E. Coli) 4) Invasins (Salmonella)
What is lysogenic conversion? Examples
- change in the phenotype of the host cell, resulting from the presence of prophage (new genotype) - Streptococcus pyogenes - making scarlet fever toxin when infected by a virus - Clostridium botulium - (food poisoning) Botulium Toxin
What is the complement system?
- collection of blood proteins that can be activated in a cascade of reactions - activation can be triggered non-specficly or specficly
What is innate (nonspecific) immunity? examples?
- do not target a specific antigen/pathogen - Innate (inborn) - Do not improve with subsequent exposures Ex: fever
What is mycosis?
- fungal disease - Candida: yeast, infection, vaginitis, thrush - Histoplasmosis - Meningitis (fungi) - ringworm - nail infection
Why are healthcare facilities susceptible?
- lots of reservoirs - Invasive Procedures - Compromised Hosts (easily infected)
What are the roles of mRNA, ribosomes, and tRNA?
- mRNA : messenger RNA, carries the coded information for making specific proteins from DNA to ribosomes - Ribosomes, move along the mRNA to assemble the amino acids into protein chains - tRNA: transfer RNA, recognize the specific codons and transport the require amino acids
What are Cytotoxic T-Cells? Function?
- mature in the Thymus - unique T-cell receptor binds antigen while its CD8 protein also binds MHC-1 protein on a host cell targeted for destruction
What are some characteristics of molds?
- multicellular -aerobic -non motile - reproduce sexual or asexually by means of spores
What are some distinguishing features of fungi?
- multicellular (mold) or unicellular (yeast) - heterotrophs - decomposers - cell wall -> chitin - some cause diseases (mycosis)
What are Natural Killer Cells?
- non-specfic - able to kill large pathogen too big for phagocytes to handle (parasites, amoebas, worms, giardia) - can also kill abnormal host cells (cancer cells) - have antibody Fc receptor - release perforin and granzymes onto the pathogen
What are diatoms?
- photosynthetic, cell wall made of glass, box doesn't die on the bottom of the ocean - kills, insects, makes paints - they fill a vacuole with oil to float (when they die we drill for oil at the bottom of the ocean)
What are point mutations? Frame- shift mutations?
- point mutations: change in single nucleotide - Substitution - often harmless - Deletion: Frame-Shift error (possibly fatal) - Insertion: Frame-Shift error (possible fatal)
How does normal flora help protect against infection?
- present in/on the body at all times
What are primary and secondary infections?
- primary - an acute infection that causes the initial illness - secondary - an infection caused by an opportunistic microbe after a primary infection has weakened the host"s defenses
What are the four signs of the inflammatory response?
- redness -swelling -heat -pain
What are some characteristics of yeast cells?
- reproduce by binary fission or budding - facultative anaerobes
What are Nematodes
- round complex bodies - Dirofliaria: heart worm - Ascaris: Human Intestinal Worm - Enterobius: Pinworms
How do anti fungal drugs like Monistat and Lamisil work?
- they use the difference between cholesterol (humans) and Ergosteral (fungi) - Monistat: targets the divergence of the two chemicals - Lamisil: liver can have worse damage taking these drugs, toxic to us
What are antimicrobial factors? Examples?
1) Acid (stomach, vaginal, skin) 2) Sebum - contains oils and fatty acids (keep skin plyable) 3) Lysozyme - digest peptidoglycan (tears, sweat, breast milk, salvia) 4) peroxidase - produces "bleach"
What are acute, latent, and persistent infections? Examples?
1) Acute - new viruses produces and released immediately (Cold Viruses, Influenza) 2) Latent - viral genome incorporates into host chromosomes as provirus and multiples with cells, then they may transition to acute after a period of dormancy (Herpes Virus) 3) Persistent - low levels of virus produced and released at all times, it may transition of acute at a later time (HIV, aids is acute, and Hepatitis)
What are the 5 steps of Lytic replication Cycle?
1) Attachment: attaches to host cell, proteins interact with outer surface of bacteria 2) Penetration: genome enters host, pushing DNA through into the bacteria 3) Biosynthesis: host cell synthesis new viral components 4) Assembly/Maturation: new viruses are assembled from components 5) Releases: host cell lyses and released viruses, viruses land on neighboring cells
What are the primary portals of entry?
1) Broken skin 2) Mucous Membrane (no skin to have absorb and move things, urinary, respiratory, reproductive, digestive) 3) Parental route (puncture, Injection, Bite, Sting)
What are four mechanisms of host damage?
1) Direct Cell Lysis 2) Siderophores 3) Collagenes and Hyaluronidase 4) Exotoxins and Endotoxins
How do viruses enter human cells?
1) Direct Penetration: non-enveloped, bacteriophage (some viruses) 2) Membrane Fussion: enveloped, both membranes of phospholipids fuse together, uncoats once in the membrane (HIV, HERPES) 3) Endocytosis: envolped or non-enveloped, fuses in the membrane and its uncoated (Influenza Virus, HPV)
What is cell-mediated immune response?
1) Infected/damaged host cell displays antigen on its surface using MHC-1 protein 2) appropriate cytotoxic t-cell binds to displayed antigen using t-cell receptor and CD8 protein 3) Cytotoxic T-Cell secretes perforin and granzyme onto host cell, which induces apoptosis 4) Perforin forms a pore in host cell through which granzyme enters and triggers pre-programmed cell death
What are interferon and interleukin?
1) Interleukin - some acts as pyrogens and generate fevers 2) Interferon - interfer with viral infection, nonspecific defense with virus
How is phagocytosis performed?
1) Mast cell releases histamine 2) Histamine dilates blood vessels which increases blood flow to the area and blood pressure drops 3) vessels become "leaky", allowing neutrophils and monocytes to craw out 4) Neutrophils - "first-responders", begin phagocytosis immediately Monocytes - differentiate into macrophage (digest with lysozyme, excrete waste) 5) pus accumulates, abscess forms 6) site heals
What are three outcomes of the complement cascade?
1) Opsonization 2) Inflammation 3) Membrane attack complex
How does each contribute to immunity?
1) Opsonization - active complements attach to the pathogen, Macrophage has active complement receptors on it 2) Inflammation - active complements are triggered, mast cells have receptors and release histamine 3) Membrane Attack Complex - active complement come into the pathogen and form pores, causing the pathogen to lysis
How do antibodies contribute to immunity?
1) Opsonization - tag a pathogen for destruction by phagocytes 2) Agglutination - antibodies "glue" multiple pathogens together to inquire phagocytosis efficiency 3) Neutralization - antibodies bind to all of pathogens binding sites to prevent it from binding to host cells 4) Complement Activation - leds to opsonization, inflammation, lyses cells, specific antibodies 5) Trigger Inflammation - antibodies attached to Fc receptor on surface of Mast Cells (releases histamine)
How does clonal selection and expansion occur?
1) Pathogen/antigen enters host 2) Appropriate B-cell binds to the antigen using it B-cell receptor and is "selected" 3) Selected B-cell undergoes many rounds of cell division to produce plasma cells and memory cells
What are Type I, Type II, and Type III exotoxins? Examples of each?
1) Type I - super antigens, causes excessive immune response (fear or blood pressure) ex: Staphylococcus aureus 2) Type II - hemolysins, break open red blood cells ex: Streptococcus pyogenes 3) Type III - A/B toxins, A- active B- binding, inhibit protein synthesis or acts as a neurotoxin ex: Clostriduim botulium (paralyze nerves)
How do pathogens avoid the immune system?
1) capsule inhibits phagocytosis ex: Streptococcus pneumoniae 2) M-protein - inhibits phagocytosis ex: Streptococcus pyogenes 3) Invasins - all ready inside the cell ex: Salmonella 4) IgA Protease - digest/breakdown protein IgA Ex: Streptococcus pneumoniae 5) Coagulase - enzyme that clots blood ex: Staphylococcus aureus 6) Kinase - enzyme that digest clots ex: Streptococcus pyogenes
What are the steps of the lysogenic replication cycle?
1) viral DNA becomes apart of bacteria chromosome 2) Binary Fission 3) Induction- environment becomes stressful (prophage senses stress in host) comes out of the chromosome
How small are prokaryotic cells?
1-10 micrometers
What are the various types of vaccines?
1. Attenuated Whole Agent: most effective, inject entire virus into the person, virus has been weakened, complete virus (MMR) 2. Inactivated Whole Agent : complete virus, can not multiply or infect cells, "dead virus" (Flu Shot) 3. Subunit : put in one antigen in its pure form, purified subunit molecule (Hepatitis B) usually a series of injections 4. Toxoid : inactivated toxin (Tetanus and Diptheria) 5. Nucleic Acid : inject DNA that encode protein, your cells display and mirrors how immune response works, genetic engineered banana s with viral proteins, get all vaccines at once
Who contributed to disproving spontaneous generation?
1. Francesco Redi (1626-1698) - covered one meat with gauze so flies could not land on it and left the other one exposed, which grew maggots on it. People said spontaneous generation needed air, this was his second experiment 2. Lazzaro Spallanzai (1729-1799) - heated broth after it was sealed so no microbes from the air could enter the flask, nothing grew (stayed sterile) 3. Louis Pasteur - used swan-necked flask, air could still get in but microbes got trapped in the neck of the flask, the broth stayed sterile
What are the stages of an infection?
1. Incubation: no signs or symptoms 2. Prodromal: mild signs/ symptoms 3. Illness: server signs/ symptoms 4. Death? 5. Decline 6. Convalescence: you are fine but still have pathogens
What steps are used to introduce human genes into bacteria cells?
1. Remove plasmid from bacteria cells 2. cut desired human DNA with restriction enzyme (scissors) 3. Cut open the plasmid 4. "Glue" gene into the plasmid with ligase 5. return the palms to the bacterial cells, make cells competent by putting them under stress 6. Harvest the desired protein
What are distinguishing features of prokaryotic cell?
1. Typically their DNA is not enclosed within a membrane and is usually singular, circularly arranged chromosome 2. DNA is not associated with histones, other proteins associated with DNA 3. They generally lack organelles 4. Their cell walls almost always contain peptidoglycan 5. They usually divide by binary fission
What are Koch's postulates?
1. microorganisms are isolated from diseased or dead animals 2. microorganisms are grown in pure culture 3. microorganisms are identified 4. injected into healthy animals 5. diseased is reproduced in healthy animals 6. microorganisms are grown in pure culture 7. identical microorganisms are identified
What is a gradient?
A gradient is an unequal distribution of something
What is a pure culture? Importance?
A population of cells descended from a single cell, it allows us to find out more about the individual bacteria
What is ATP and why is it important?
Adenosine Triphosphate - ENERGY - is required for active transport.
Who pioneered the discovery of antimicrobials?
Alexander Flemming (discovered penicillin)
Who was the first to see microorganisms? How? When?
Anton Leeuwenhoek was the first to see microorganisms. He lived from 1632 to 1723 and was an expert lens grinder. He could observe much smaller particles with his microscopes than others could. He collected rainwater and was the first to see living microorganisms. He also took his teeth scrapings and was the first to observed bacteria. When he took scrapings from rotten teeth, he saw an abundant amount of bacteria. Leeuwenhoek then concluded that the diseased teeth were causing the bacteria.
What is an autoclave? How does it work?
Autoclave uses pressure to increase the boiling temp of H2O, 121◦C @ 15psi for 15mins sterilizes
What is transformation?
Bacteria take up DNA from the environment - DNA is very large and polar, does not pass easily across the cell membrane, for cells to bring DNA across their membrane they must be competent
What are binary fission and generation time?
Binary fission: process by which bacteria reproduce Generation time: the time required for the population to double (30 mins under ideal conditions)
How do enveloped viruses exit host cells?
Budding - spike proteins tell where cell needs to push through, original membrane becomes host membrane (HIV) Neuramindose: needed for budding, escaping, cuts the "ropes" holding it down so it can escape Hemagglutin: used for attachment, entering H1N1
What is the overall reaction of aerobic cellular respiration? How many ATP are produced from it?
C6H12O2 (Glucose) + 6O2 --> 6CO2 + 6 H2O (exergonic) 38 ADP + 38P --> 38ATP (endergonic)
What is the endosymbiotic theory? Evidence?
Cells living within cells to survive together. Rodshape, Double membrane, prokaryotic (bacterial version)m circular chromosomes, replicate by binary fission, DNA sequence homology Lynn Margulis - proposed Endosymbiotic Theory
How does penicillin work? Lysozyme?
Fleming discovered: Lysozyme, digest peptidoglycan, disrupts connection, cells then burst and break open - Penicillin: inhibits dehydration synthesis of amino acid crosslinks, it can not build bonds, it can not kill existing cells, but kills the new cells it works on gram positive
What is fermentation?
Formation of alcohol from sugar
What is glycolysis? ATP production?
Glucose --> 2 CCC chains (pyruvic acid) 2H+ 2-E 2ADP + 2P --> 2 ATP
What were historically thought to be causes of disease?
God's wrath, Satan/Evil Spirits, Foul Vapor, Imbalance of humors (fluids) making too much of one, Germ Theory of Disease (1870s) Pasteur and Koch
What are HAIs? Significance?
Healthcare Associated Infections - infection acquired at a healthcare facility - 15% of patients get one - Staphylococcus aureus - Pseudomonas aeruginosa
What are Helper T-Cells and T-cell receptors?
Helper T-cells: Recruit other cells to fight the invaders. Interact directly with B cells T-cell receptor: not an antibody, multiple copies, 1 binding site, never secreted (antigen recognition only)
What roles are played by MHC-1 and CD8 proteins?
Host cell displays antigens on its MHC-1 proteins the cytotoxic T-cell uses its CD8 protein to bind to the MHC-1
How do antiviral drugs such as Tamiflu work?
How do antiviral drugs such as Tamiflu work? Neuramindose inhibitor, inhibit the cutting off the ropes, mature viruses can't escape your cells, keep numbers down
What roles for IgG, IgM, IgA, IgD, and IgE play in immune response?
IgG : monomer, most abundant in blood serum (80%), defends by all mechanisms expect inflammation, only antibody that can cross the placenta IgM : pentamer, 10 antigen binding sites, first antibody produced after exposure to new antigen, monomer version is anchored to B cells to serve as B cell receptor IgA : dimer, abundant in mucous, saliva, breast milk, tears, sweat, usually what pathogen encounters first, neutralization IgD : monomer, not sure what it does IgE : monomer, becomes bound to Fc receptors on Mast cells and triggers inflammation, allergic reactions and hypersensitivity
How does incidence differ from prevalence?
Incidence: Fraction of a population that contracts a disease during a particular period of time Prevalence: the fraction of a population having a specific disease at a given time
How does normal flora benefit a host?
It fights off "bad" bacteria
What is peptidoglycan? Chemical Structure?
It is a polymer of saccharides and amino acids. 1. N-acetyl muramic acid (NAM) 2. N- acetyl glucaseamine (NAG) it is only found in bacteria. It is an alternation chain of NAGs and NAMs, only NAM is involved in the cross link bonding
What is a cell wall? Why is the cell wall important?
It is a rigid structure, that protects against water uptake. It is made up of peptidoglycan
What contributions did Koch make to microbiology?
Koch discovered rod shaped bacteria (Bacillus). He cultured the bacteria, and injected them into healthy animals. He discovered that the two sets of blood cultures contained the same bacteria. He discovered the cause of anthrax
What are the stages of bacterial growth curve?
Lag - slow beginning growth Log - long, rapid growth Stationary - no more growth, maintain stationary numbers, equal amount of dead and living cells Death Phase - most of the cells die
What is the theory of spontaneous generation?
Life arises spontaneously from non-living materia
How do non-enveloped viruses exit host cells?
Lysis - used by non-enveloped virus, no cell wall (no need for lysozyme) (HPV)
What are roles played by MHC-2 and CD4 proteins
MHC-2 : the host cells uses this to display antigens on the surface of the cell CD4 : a protein on helper T-cells that binds to the MHC-2
What roles are served by Mast cells and histamine?
Mast cell releases histamine - histamine is a vasodilator (dilates blood vessels) which increases blood flow to the area and blood pressure drops
What roles do microorganisms play in the environment, food production, and biotechnology?
Microorganisms play a role in the environment with O2 production via photosynthesis and also with decomposition and nutrient recycling. They play a role in food production with bread, beer, wine, yogurt (Lactobacillus acidophilus), and cheese. They play a role in biotechnology with genetic engineering (producing human insulin) and gene editing (CRISPR method)
What impacts have microorganism had on history?
Modern science came from history, like the plague. For example, in 1521 when Cortez conquered the Aztecs bringing over smallpox and in 1860 during the civil war most people died from the infections, which could have changed some results in both these historical events.
What are hemagglutinin and neuraminidase?
Neuramindose: needed for budding, cuts the "rope" holding it down so it can escape Hemagglutin: used for attachment (entering)
What physical barriers are involved with immunity?
Non-specfic defenses 1) Intact Skin - decomposing, dry, scaly, salty, acidic inhospitable 2) Mucous Membrane - thick mucous, ciliary escalator 3) Normal Flora
What is the growth rate equation?
Nt = Nt0 x 2^n n=the number of doublings
What is osmosis? Importance in microbiology?
Osmosis is the diffusion of solvent (H2O) from higher solvent concentration to lower solvent concentration. It is Simple diffusion, the net movement across the membrane
What is the glycocalyx
Outer covering composed of carbohydrates. Used for attachment and helps avoid white blood cells of the immune system
Who developed the germ theory of disease
Pasteur and Koch
What are pathology, etiology, and pathogenesis?
Pathology: Study of disease Etiology: cause of disease Pathogenesis: process of disease
What are perforin, granzyme, and apoptosis?
Perforin - a protein that makes pores in target cell membrane Granzyme - proteases that induce apoptosis, are able to enter the pathogen through the pores Apoptosis - the natural programmed death of a cell, the residual fragments are disposed by phagocytosis (no inflammation)
What are plasma cells and memory cells?
Plasma cells: Secrete large quantities of antibodies specific for the antigen (lose their BCRs and focus on secretion) Memory cells: do not secrete antibodies, produce B-cell receptors and remain in circulation to increase efficiency of response during secondary exposure
What are plasmids?
Plasmids are small loops of extra DNA that aren't part of the chromosome. Plasmids contain genes for things like drug resistance and can be passed between bacteria.
How does membrane filtration work? Pore size?
Pour liquid through filter with very small pores (smaller than 0.04 micrometers) the bacteria is caught in the filter
What are facultative anaerobes?
Prefer O2, but can live without it ( E. Coli)
What are prokaryotes and eukaryotes?
Prokaryotes have no nucleus and no internal membranes. Eukaryotes have a nucleus and have internal membranes.
What is the transition reaction?
Pyruvic acid + CoA --> CC-CoA + CO2 --> 2H+ +2E-
How is a gene transcribed? What is RNA polymerase?
RNA polymerase binds to start of gene at the promoter sequence - Synthesizes complementary mRNA in a 5' to 3' direction - RP falls off at the terminator sequence - mRNA is released and moves toward ribosome
What is a replication fork? Origin?
Replication fork is the separation of the parent strands (where is is being unzipped) - The origin is where the replication begins
Who pioneered the culturing of bacteria? How?
Robert Koch, he used a potato slice and saw pure cultures, then gelatin (but melts at body temperature) and then used agar in a Petri Dish
What are ribosomes?
Site of protein synthesis (30s 50s bacteria), prokaryotic ribosomes are structurally different than Eukaryotic ribosomes)
What are the start and stop codons? Why necessary?
Start: AUG Stop: UAA, UAG, UGA tell where the gene should be translated
What are substrate, product, and active site?
Substrate are the reactants that fit in the enzymes active site to produce a certain product.
What is a anabolic reaction?
Synthetic energy (requires energy), Endergonic (needs energy) A + B ---> C, life has been found to harness this energy
How is DNA replicated?
The DNA molecule separates into two strands and then follows the rules of base pairing to build two new complementary strands. The nitrogenous bases on the original strands code for the arrangement of nucleotides in the new strands. For example, if the original strand contains guanine, then cytosine is added opposite it in the newly forming strand.
When was the "Golden Age of Microbiology"
The Golden Age of Microbiology was a 50 year period between mid 1800's and early 1900's
How do sulfa drugs work? Why are they safe?
The competitively inactive bacteria enzymes. Shut down the formation of bacterial folic acid, the bacteria can't make DNA. It is safe because humans do not have this enzyme, we have to get it premade from food
What are the various types of microorganisms?
The first category is Bacteria. These are unicellular, prokaryotic (no nucleus and no internal membranes), have a cell wall that contains peptidoglycan, and are the most abundant life form. The second group is Archae. These are unicellular, prokaryotic, and they live in extreme environments. The third group is the Eukarya. These can be unicellular or multicellular, Eukaryotic (nucleus and internal membrane), and there are 4 kingdoms (Animali, Plantae, Fungi, and Protista).
What questions did scientist attempt to answer?
The four key question these scientist attempted to answer were: 1. Does life arise spontaneously? 2. What causes fermentation? 3. What causes diseases? 4. How can disease be prevented?
What is Major Histocompatibility Complex (MHC)?
The genes that code for molecules of genetically diverse glycoproteins - Class I MHC: are found on the plasma membranes of mammalian nucleated cells, they identify "self" from foreign - Class II MHC: exist only on the surface of (APCs, including B-Cells)
What makes adaptive immunity specific?
The immune system targets specific pathogens
How did the plague contribute to microbiology?
The plague contributed to microbiology because it made people start to ask questions of why this was occurring. Some believed it was God's punishment for sin and others had more rational reasons, which lead to modern scientific explanations. The plague ultimately lead to the upbringing of the Germ Theory, which said that it was caused by bacteria.
What allows for enzyme specificity
The shape of the active sites
What makes Bacillus and Clostridium difficult to control?
They both produce endospores and endospores are very hard to kill
How have viruses been linked to tumor formation?
They cause a mutation, which cause the cells to form a tumor
What cause inflammation?
Tissue damage, complement proteins, antibodies
What roles do proteins play in the membrane?
Transport, structural, receptors, and enzymes
What are viruses
Viruses are nonliving obligate intracellular parasites.
How does irradiation work? Wavelengths?
Wavelengths of electromagnetic energy, 254 nanometers works best to denature bacterial protein DNA
What is meant by the term etiology?
What caused the disease
What is complementary base pairing?
When base A always pairs up with base T, and base C always pairs up with base G, in DNA
Sign
a chance due to a disease that a person can observe and measure
Symptom
a change in the body function that is felt by a patient as a result of a disease
non-communicable disease
a disease not capable of being spread from one person to another
Contagious
a disease that is easily spread from one person to another
What are obligate aerobes?
aerobes? must have O2 (Pseudomonas aeruginosa)
Communicable
any disease that can be spread from one host to another
What are vaccines?
artificial exposure to antigen in order to develop an active immune response
What is septic shock?
bacterial toxins trigger vasodilation and increased capillary permeability (excessive immune response)
What are obligate anaerobes?
cannot have O2 (Clostridium botulium)
What are antigen-presenting cells (APCs)?
cells that process an antigen and display it to a T cell A macrophage that displays antigens on its surface using MHC-2 protein
What is the structure of the cytoplasmic membrane?
consists primarily of phospholipids arranged in a bilayer, also contain proteins (transport, receptors, ligands, enzymes) regulates what enters and exits the cytoplasm (selectively permeable)
What is a chromosome?
contains genetic information
How are viruses cultivated in the laboratory?
culture viruses with in tissues AND within chick embryos
What is adaptive (specific) immunity)
defense that protects you against specific pathogens breach the immune system -->lymphocytes (T and B cells & antibodies)
tumor-suppressor genes
encode protein that turn off cell division (P53 gene)
Proto-oncognes
encode proteins that turn on cell division
What is meant by energy coupling? Examples?
energy released from Exergonic, fuels the endergonic. Examples: Cellular Respiration, producing urea
What is induction?
environment becomes stressful (prophage senses the stress to host) and comes out of the chromosome
What is conjugation?
exchange of DNA by means of a plus
What is transduction?
exchange of DNA by means of a virus
What are protozoans?
heterotrophs - motile (flagella, cilia, pseudopods) - unicellular - 2 stages : trophozile (active) and cyst (dormant) - no cell wall (can't engulf food) - pathogens
What is metabolism?
is the sum of all biochemical reactions occurring in a cell
What is meant by a competent cell?
it can bring DNA across its membrane
What is normal flora? Example?
microorganism that are present on the body at all times - Lactobaccilus acidophilus - Staphylococcus epidermidis - E. Coli
What is a formite? example
nonliving object that play the middle mad for transmitting pathogens - toys, doorknobs, equipment
What are opportunistic pathogens? example?
normal flora the causes disease in other location - C. ablicans (vaginal or throat) - E. Coli (urinary tract, lungs)
What is meant by the term anti-parallel?
one strand runs 5' - 3' and the other runs 3' - 5'
What are neutrophils, acidophiles, and alkaiphiles?
pH requirements -Neutrophiles: pH 5-8 (humans 7.35) - Acidophiles: pH<5 - Alkaliphiles: pH>8
Horizontal gene transfer?
passing genetic information within a generation - Transformation, conjugation, transduction
Edward Jenner
performed variation using cow pox scabs to avoid getting small pox
What is translation and how does it occur?
process by which RNA is decoded (translated) into the primary structure of a protein (amino acid sequence) occurs at ribosome
What is meant by negative feedback?
product of a process inhibits the process, comes back and blocks the active site
What are enzymes?
proteins with specific 3D-shape that catalyze (speed up) specific biochemical reaction. It does not provide energy. It lowers the activation energy requirement. Has a specific active sites for specific substrates
What is a gene?
region of a chromosome that encodes for a specific protein
What are microenvironments? Example?
small sub environment with conditions that differ from the macroenvironment ex: air condition, Helicobacter pylori has a pH of 7 but lives in the wall of the stomach that has a pH of 2. Uses NH3 to neutralize stomach acid
What is meant by the terms sterilize, sanitize, degerm, and preserve?
sterilize - destroy/ remove ALL microorganisms (includes endospores) Disinfect - destroy/remove MOST microorganisms Sanitize - reducing the number of microorganisms to a level that is safe Degerm - physcail removal of microorganisms from a limited area ( alcohol wipe or hand washing) Preserve - slow or inhibit growth (fridge-rate)
What is meant by competitive inhibition
substance other than the product competes for binding to the active site. Sulfanilamide is a competitive inhibitor
How do cytokines contribute to nonspecfic immunity?
substances that direct and influence immune response 1) Interleukin 2) Interferon
Why are endotoxin (LPS) and mannose important?
the are non-specfic complement protein activation
Why is sterilization particularly important for hospitals?
the spread of bacteria in hospitals can be detrimental with no sterilization
What is prophage?
the viral DNA that is embedded in the host's DNA
What roles do B-lymphocytes and T-lymphocytes play in the immune system?
they are apart of the specific adaptive immunity
What is cancer?
uncontrolled cell growth
What are bacteriophage?
viruses that infect bacteria cells (lytic and lysogenic cycle)
What are microaerophiles?
want low levels of oxygen (Helicobacter pylori)
What are helminths?
worms heterotrophs - cestodes, trematodes, nematodes
How do RNA and DNA differ?
DNA differ? - RNA: ribose, single stranded, AUGC - DNA: deoxyribose, double stranded, ATGC
What is catabolic reaction?
Decomposition (Degradative) reactions, exergonic (release energy) Z---> X + Y, low energy state, spontaneous
What are psychrophiles, mesophiles, thermophiles, and hyperthermohiles?
Degrees Celcius -Psychrophiles: -5 to 20 "cold lovers" - Mesophiles: 20 to 45 (body temp 37) - Thermophiles: 45 to 70 "heat lovers" - Hyperthermophiles: 70 to 110 "extreme"
What are disinfectants and antiseptics?
Disinfects remove most microorganisms. Disinfectants are chemicals/lysol. Antiseptics are suitable for use on tissues (skin)
What are aerotolerant anaerobes?
Do not use O2, but can live in it (Streptoccus pyogens)
What are endergonic and exergonic reactions?
Endergonic - energy is absorbed from surrounding exergonic - energy is released to surrounding