Microbiology Final Exam
What contributes to the virulence of a pathogen?
# of microorganism that gain access to a host evasion of host defenses toxin production
What are five functions of antibodies?
They prevent pathogens from entering or damaging cells by binding to them; Enhances phagocytosis
How are macrophages recruited to the site of an infection? What role does vasodilation and diapedesis play in this recruitment?
They recognize PAMPS that are foreign to the body via PRR's. During phagocytosis histomine are released cause vasodilation which widens the blood cells and becomes leaky which allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage
Gyrase
Uncoils the DNA strand in replication
Virulence Factor
Virulence factors help bacteria to (1) invade the host, (2) cause disease, and (3) evade host defenses. The following are types of virulence factors capsules (protects them from phagocytosis), endotoxins and exotoxins, pili
Discuss the influence of virulence factors on pathogenicity
Virulence factors make it easier for an organism (bacteria, virus) to cause disease
MHC I
When cells are infected with viruses, they express MHC 1 molecules.This allows cytotoxic T cells to destroy infected cells.
Vasodilation
When tissue is first injured, the small blood vessels in the damaged area constrict momentarily, a process called vasoconstriction. Following this transient event, which is believed to be of little importance to the inflammatory response, the blood vessels dilate (vasodilation), increasing blood flow into the area. One of the best-known chemical mediators released from cells during inflammation is histamine, which triggers vasodilation and increases vascular permeability
Antibody
Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. a protective protein produced by the immune system in response to the presence of a foreign substance, called an antigen. Antibodies recognize and latch onto antigens in order to remove them from the body.
Invasins
a class of proteins associated with the penetration of pathogens into host cells.[1] Invasins play a role in promoting entry during the initial stage of infection
Phagolysosome
a cytoplasmic body formed by the fusion of a phagosome with a lysosome in a process that occurs during phagocytosis. Formation of phagolysosomes is essential for the intracellular destruction of microorganisms and pathogens.
Inflammatory response
a defense mechanism that evolved in higher organisms to protect them from infection and injury. Its purpose is to localize and eliminate the injurious agent and to remove damaged tissue components so that the body can begin to heal. The response consists of changes in blood flow, an increase in permeability of blood vessels, and the migration of fluid, proteins, and white blood cells (leukocytes) from the circulation to the site of tissue damage.
Immunological Memory
a distinct characteristic of the immune system and it relates to its ability to remember antigens on pathogens--> memory b cells memory cells that remember the same pathogen for faster antibody production in future infections.
competitive inhibitor
a form of enzyme inhibition where binding of an inhibitor prevents binding of the substrate.
CD4
a glycoprotein found on the surface of immune cells such as T helper cells, monocytes, macrophages, and dendritic cells. a co-receptor of the T cell receptor (TCR) and assists the latter in communicating with antigen-presenting cells.
Artificial immunity
a mean by which the body is given immunity to a disease by intentional exposure to small quantities of it. Active artificial- The pathogen is introduced into the body through a vaccine before they are infected. Long lasting example: being immunized or vaccinated for polio Passive artificial: antibodies are injected into a person at the time they are infected ex: anti-tetanus injection
What is quorum sensing
a method of communication among bacteria -Allows for bacteria to coordinate gene expression and function as a population rather than individual cells Bacteria release auto inducers
substrate
a molecule acted upon by an enzyme. A substrate is loaded into the active site of the enzyme
TCR
a molecule found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules.
Inflammation
a process by which the body's white blood cells and substances they produce protect us from infection with foreign organisms, such as bacteria and viruses. chemicals from the body's white blood cells are released into the blood or affected tissues to protect your body from foreign substances. This release of chemicals increases the blood flow to the area of injury or infection, and may result in redness and warmth
Phagocytosis
a process wherein a cell binds to the item it wants to engulf on the cell surface and draws the item inward while engulfing around it. The process of phagocytosis often happens when the cell is trying to destroy something, like a virus or an infected cell, and is often used by immune system cells.
Antibody
a protective protein produced by the immune system in response to the presence of a foreign substance, called an antigen. Antibodies recognize and latch onto antigens in order to remove them from the body.
Exotoxin
a toxin released by a living bacterial cell into its surroundings. can cause damage to the host by destroying cells or disrupting normal cellular metabolism. They are highly potent and can cause major damage to the host. Secreted by Gram positive bacteria. Toxin are proteins that break down with heat. Very toxic and can be fatal.
Chemokine's
a type of cytokine that is produced as a "chemo-attractant molecules" i.e to attract cells to sites of infection/inflammation (recruit neutrophils)
Cell-mediated immunity
an immune response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
Macrophage
are a type of white blood cell, of the immune system, that engulfs and digests foreign substances, microbes, cancer cells, and anything else that does not have the type of proteins specific to healthy body cells on its surface in a process called phagocytosis. Recognize patterns Macrophages, a kind of white blood cell, are the first cells at the scene of infection, and they get there from your blood. Infected or damaged cells, like the epithelial cells in our story, call for help by releasing chemicals to attract macrophages. Think of macrophages as cell-eating machines. First, the macrophage surrounds the unwanted particle and sucks it in. Then, the macrophage breaks it down by mixing it with enzymes stored in special sacs called lysosomes. The leftover material is then pushed out of the cell as waste. Not only do macrophages keep the body clean of debris and invaders, they also call for backup when an infection is too big for them to handle alone. Other immune system cells, like the T-Cells and B-Cells in our story, are alerted that their help is needed by chemicals the macrophages release.
Adhesins
are cell-surface components or appendages of bacteria that facilitate adhesion or adherence to other cells or to surfaces, usually the host they are infecting or living in. Adhesins are a type of virulence factor. -fimbriae and pili
Pathogen Associated Molecular Pattern (PAMP)
are molecules associated with groups of pathogens, that are recognized by cells of the innate immune system. They are recognized by toll-like receptors (TLRs) and other pattern recognition receptors (PRRs). Examples are: LPS (lipopolysaccarides), lipotechoic acid, flagellum and peptidoglycan
Lysosomes
are organelles that contain digestive enzymes. They digest excess or worn out organelles, food particles, and engulfed viruses or bacteria.
Toll-like receptor
bind to specific molecules produced by bacteria. Toll-like receptors are a key part of the innate immune system because, once bound to a bacterial pathogen, they recognize the specific bacteria and activate the immune response. There are lots of different types of Toll-like receptors produced by the body, all which bind different molecules.
noncompetitive inhibitor
binds to a different site that is not the active site of the enzyme and changes the structure of the enzyme; therefore, it blocks the enzyme from binding to substrate, which stops enzyme activity.
professional antigen presenting cell
group of immune cells that mediate the cellular immune response by processing and presenting antigens for recognition by certain lymphocytes such as T cells. Examples are Macrophages and B cells
Bacteriophage Therapy
he utilization of viruses to invade bacteria, causing the disruption of bacterial metabolism, causes cells to lyse, targets and affects only specific bacteria -Used against Cancer cells
T cell receptor
is a molecule found on the surface of T cells, that is responsible for recognizing fragments of antigen as peptides bound9870-=9 to major histocompatibility complex (MHC) molecules.
Immunocompromised
is a patient who does not have the ability to respond normally to an infection due to an impaired or weakened immune system.
Phagosome
is a vesicle formed around a particle engulfed by a phagocyte via phagocytosis.
Oxidative Burst
is the rapid release of reactive oxygen species (superoxide anion and hydrogen peroxide) from different types of cells. Usually it denotes the release of these chemicals from immune cells, such as neutrophils and macrophages because they are infected by different bacteria
Types of phagocytes
many types of white blood cells (such as neutrophils, monocytes, macrophages, and dendritic cells
What is a hemolysin, and what benefits does it afford bacteria?
means that the red blood cells burst apart (hemolyse) and release the cell contents (hemoglobin).Type of virulence factor. Leaves a clear zone around bacterial growth. A function of hemolysins is that the bacteria can utilize hemolysis to release and utilize nutrients from the host animal cells. Iron e.g., is essential to many pathogenic bacteria, but is only present in very low concentrations outside the cells. If the bacteria have access to free hemoglobin, it can utilize the iron, which is bound to the heme groups of hemoglobin
Antibiotic resistant
occurs when bacteria change in a way that reduces the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. The bacteria survive and continue to multiply, causing more harm. Hydrolysis of antibiotic Efflux pump Mutation of gene target Antibiotic modification
Conjugate vaccine
part of virus , stimulation of TH, and B created by covalently attaching a poor antigen to a strong antigen thereby eliciting a stronger immunological response to the poor antigen. Usually a weak capsular polysaccaride paired with strong toxin because strong toxin will produce strong immune response
Subunit vaccine
part of virus, stimulation of TH, and B Needs boosters and refrigeration required contains only specific protein subunits of a given virus
Toxoid vaccine
part of virus, stimulation of TH, and B Needs boosters. made from a toxin (poison) that has been made harmless but that elicits an immune response against the toxin
Diapedesis
passage of blood cells (especially white blood cells) through intact capillary walls and into the surrounding tissue.
pattern recognition receptors (PRR's)
play a key role in the innate immune response by recognizing conserved pathogen associated molecular patterns (PAMPs)
Cytokines
small proteins that are important in cell signaling. Their release has an effect on the behavior of cells around them. send signals out to other cells, such as macrophages and other lymphocytes, telling them to come over and help. Causes inflmmation because chemicals from the body's white blood cells are released into the blood or affected tissues to protect your body from foreign substances. This release of chemicals increases the blood flow to the area of injury or infection
Describe the two methods talked about in class that is currently being researched and how are they used?
systematic placement. how scientists have been trying to genetically engineer bacteriophages so that they can bind to eukaryotic cells as well, and specifically some of the receptors that appear on the surface of these cancerous cells.
psychrophile
-5-20 Best at 10
Measuring effectiveness of Antibiotics
-Effectiveness determined by MIC
Steps of phagocytosis
1) Attachment to something foreign -PAMP- PRR (pathogen to macrophage) 2) Phagocytic vesicle forms -Phagosome form 3) phagosome matures -Drops pH- starts killing process, disrupts cellular protein/structure 4) Digestion - lysozyme merges w/phagosome>releases digestive enzymes>becomes a phagolysosome - microbes are usually killed at this point from enzymes in lysozome 5)Ingested pathogen is killed in phagolysosome -- phagocytes eliminate remaining pieces of microbe via exocytosis - some components are saved to alert immune system if pathogen were to try and invade again
acidophile
1-5.5 Best at 3
Mesophile
15-45 Best at 37
Thermophile
45-80. Best at 60
neutrophil
5.5-8.5 Best at 7
hyperthermophile
65-105 Best at 85
alkalophile
7.5-11.5 Best at 9.5
CD8
A glycoprotein found on the surface of immune cells such as Tc cells. Binds to MHC I
List what a phagocyte (cells that perform phagocytosis) secretes during phagocytosis of a foreign object and the function of two specific secreted molecules.
A phagocyte secretes cytokines and chemokines. Cytokines cause inflamation and chemokines recruit neutrophils
T-helper cell
A type of T cell that provides help to other cells in the immune response by recognizing foreign antigens and secreting substances called cytokines that activate T and B cells. Once bound, the helper T cell proliferates to form a clone of cells, each capable of recognizing the same antigen. The members of the helper T clone, the generals, generate the chemical signals that call up the troops.
Neutrophil
A type of white blood cell that contains little sacs containing enzymes that digest microorganisms.
Acquired Immunity
Acquired immunity is immunity that develops with exposure to various antigens. Your immune system builds a defense against that specific antigen.
Describe the process of the Human T-Cell Leukemia Virus type 1 after it has been transmitted into the human body.
After HTLV-1 has entered the human body, reverse transcription (making DNA from RNA template) of the virus takes place. The genome of the virus is transmitted into the healthy human cell and the virus is then able to replicate. Once the infected cell begins to replicate it will spread the virus throughout the rest of the body.
Active Immunity
Antibodies produced in the body in response to an antigen
Antigen
Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria. Nonliving substances such as toxins, chemicals, drugs, and foreign particles (such as a splinter) can also be antigens. The immune system recognizes and destroys, or tries to destroy, substances that contain antigens.
Explain the immunological function of B, TH, and TC cells
B cell- create antibodies Th cell- help activate b and tc cell TC cells- kill targeted cells
Explain the process by which a B cell that has bound a bacterial pathogen is activated (or licensed) by a TH cell. What does a licensed plasma B cell produce?
B cells require T-cell help to produce specific antibody. When T helper cells are activated they produce proteins that activate B cells. TH cells binds to B cells MHC II complex. Whe B cells are bound to a pathogen and is activated produces antibodies. A licensed plasma B cell produces antibodies.
Transduction
Bacteriophage transfer genetic information, recombination, requires homology
What is one way that Human T-Cell Leukemia Virus type 1 is transmitted?
Bodily fluids (breastfeeding or sexual intercourse or blood transfusions)
Compare TC and NK cells
Both of them are cytotoxic immune cells that are capable of killing foreign pathogens and also cancer cells. However they belong to different systems within the immune system. Can only bind when there's MHC I. Natural killer (NK) cells belong to the innate immune system. They generally serves as a first line of defence against foreign pathogens. This include bacterial or virus particles or virus infected cells. NK cells are not specific in their immune response. In the sense that they recognise a wide variety of bacteria so any bacteria will activate them. This is good because when you spot an enemy, you kill, right? NK cells also have the ability to sense stressed cells ie) cells that are infected with a virus or are turning cancerous. They will seek them out and destroy them before they do any harm. T cells belong to the adaptive immune system. They are highly specific ie) only hunt down 1 enemy, often disregarding the rest.
What is released by dinoflagellates of the red tide that causes respiratory distress when breathed in by humans?
Brevetoxins
Antibiotics
Broad Spectrum- They can target multiple organism Narrow Spectrum- Can only target few gram positive -Target and inhibit growth of bacteria and don't have an effect on human cells.
Endotoxin
By gram negative bacteria. Toxin is present on outer cell wall ( lipoplysasccharides), less toxic, has a localized effect, heat stable
Typhoid fever
Can spread through contaminated food or water. There are vaccines inactivated and live
Obligate anaerobes
Cannot survive in O2
Morphology
Coccus- Circular Bacillus- Oval Strepto- chain Staphylo- cluster
What do Tc and NK cells secrete when they recognize a foreign antigen or foreign cell?
Cytokines- Granzymes and perforin
T-cytotoxic cell
Cytotoxic T cells (also known as killer T cells) bind cells that have been altered, such as by viral infection; they avoid healthy cells. Surface antigens on the altered cell perform the binding. These antigens are specific to the offending agent, and match receptors in the membrane of the specific TC cell. In addition, the TC cell simultaneously binds an MHC I molecule on the surface of the infected cell. Once bound by both the foreign antigen and the HLA molecule, the cytotoxic T cell secretes a chemical called "perforin," and granzymes which destroys the infected cell
Active site
the region of an enzyme where substrate molecules bind and undergo a chemical reaction.
Describe herd immunity and the function of its design
the resistance to the spread of a contagious disease within a population that results if a sufficiently high proportion of individuals are immune to the disease, especially through vaccination.
Transformation bacteria
DNA from the environment, competent cell (bacteria are capable of being transformed), recombination, requires homology
Replication
DNA--> DNA using DNA polymerase
Transcription
DNA--> RNA using RNA polymerase
Inactive vaccine
Dead, whole, can't replicate, stimulation of Th, and B. Not Tc cells since the virus is dead and can't replicate so won't have any antigens presented on MHCI Needs boosters to maintain immunity
Facultative anaerobe
Does not require O2, but can survive
Final electron acceptors in glycolysis and electron transport chain
ETC- Oxygen Glycolysis - Glucose-->pyruvate
describe the function of a virulence factor.
Factors that are produced by a microorganism and stimulate disease are called virulence factors. Examples are toxins, surface coats that inhibit phagocytosis, and surface receptors that bind to host cells.
Psychrotroph
Grow best at or around room temperature, but can grow at refriderated (8 C) and temperatures above room temperature (up to 30-35 C). Typically will not grow at body temperature.
Acidotolerant
Grows equally well at pH 7 as it does in pH 4, 5, and 6. Does not grow in extreme acidity, as do some acidophiles
Nonhalophile
Grows in media with salt concentrations from 0-4 or 6%. Growth consistently declines as salt concentration is increased
Describe how antibodies and TH cells enhance phagocytosis
Helper T (TH) cells are critical to coordinating the activity of the immune response. The chemical messages they secrete (cytokines) stimulate the non-specific immune response to continue, and strengthen and boost appropriate specific responses. Antibodies work by blocking the receptors that allow pathogens to attach to target cells, or by creating clumps of bacteria. Clumping makes the job of phagocytes easier, as they will more readily engulf bacteria in clumps
B cell
Helper T cells also stimulate the production of antibodies. Chemical signals from helper T cells stimulate the production of B cells specific to an infecting pathogen, and then stimulate the B cells to differentiate into plasma cells. The plasma cells are factories for the production of antibodies, which are specific to given pathogens circulating in blood or lymph. Antibodies work by blocking the receptors that allow pathogens to attach to target cells, or by creating clumps of bacteria. Clumping makes the job of phagocytes easier, as they will more readily engulf bacteria in clumps. Recognize specific pieces of pathogen
Explain why the threshold for herd immunity of a vaccine like the measles vaccine is so high.
How easily transmissible the disease is
Aerobic respiration
If cells use oxygen to make ATP, it's considered aerobic respiration. -Aerobic respiration is last used in the ETC -The function is to regenerate NAD+ and FAD with free energy to create ATP and to reduce O2 to H2O -occurs at the membrane -32 atp
Adaptive Immunity
If the body's first line of defense - the innate immune system - is unsuccessful in destroying the pathogens, after about four to seven days the specific adaptive immune response sets in. This means that the adaptive defense takes longer, but it targets the pathogen more accurately. Another advantage: It can remember the aggressor and acts specifically against certain antigens. If there is new contact with an antigen that is already known, the defense response can then be quicker. This way the defense responses of the adaptive immune system are more efficient and faster than those of the innate defense, if the antigen is already known. The adaptive immune system can remember the antigens because it produces memory cells Adaptive immune cells = Th, Tc, and B cells adaptive immune cells recognize specific antigens.
Natural immunity
Immunity that is naturally existing, Natural immunity does not require prior sensitization to an antigen. (innate immunity) Active natural- pathogens enter the body in a natural manner- ex: catching a cold Passive natural- antibodies enter the body in a natural matter ex: antibodies cross the placenta into the fetus
The influenza vaccine is an attenuated vaccine of 3-4 strains that are predicted to be the most prevalent during the upcoming flu season. Describe why an immunocompromised individual should not receive this vaccine.
Immunocompromised immune system is weaker, so they don't have like the T cells and other cells to fight off the virus and they would have a higher chance of actually getting the live disease
Describe how inflammation contributes to immune response
Inflammation is the body's normal response to injuries or infections. Cells of the immune system travel to the site of injury or infection and cause inflammation. chemicals from the body's white blood cells are released into the blood or affected tissues to protect your body from foreign substances. This release of chemicals increases the blood flow to the area of injury or infection. Its purpose is to localize and eliminate the injurious agent and to remove damaged tissue components so that the body can begin to heal.
innate immune system
Innate, or nonspecific, immunity is the defense system with which you were born. It protects you against all antigens. Innate immunity involves barriers that keep harmful materials from entering your body. These barriers form the first line of defense in the immune response. Examples of innate immunity include: If an antigen gets past these barriers, it is attacked and destroyed by other parts of the immune system.The innate immune system tells the adaptive immune system when it's time to help mount a defense Innate immune cells = macrophages, neutrophils, and NK cells Innate immune cells recognize general patterns .
Anaerobic respiration
Krebs cycle, glycolysis and ETC NO3- CO32- SO42- final e acceptor
Growth characteristics and stages of growth
Lag metabolically active, preparation for growth in environment, no growth Log rapid growth (fastest generation time) Stationary nutrients deprived, growth slows, equal numbers of growth and death Death Phase nutrients depleted, waste products present at high concentrations, bacterial death at logarithmic rate
What part of the bacterial cell envelope is also known as endotoxin? Which organisms produce endotoxin?
Lipopolysaccharides (LPS)- Outer membrane of Gram- negative
Attenuated vaccine
Live, whole, can replicate and some antigens will be presented on both MHC I and MHC II Stimulation of Tc, Th, and B, don't need a booster because Tc cells allow for a full complement of the adaptive immune system. Usually lifelong immunity, Limitations: Refrigeration required; possibility to revert to orginial form; can't be given to immuno-deficient people
Conjugation
Must be physical attachment between donor recipient. Bacterial mating, requires a pilus, F-plasmid, F- and F+
During a red tide, saxotoxins are released and ingested by fish causing an interruption in ________ leading to paralysis and death.
Na+ channels
NK cell
Natural Killer cells are important part of the innate immune system. They are a backup plan They specialize in identifying cells that are infected by a virus or that have become tumorous. They do this by looking for changes in cell surfaces. THey look for MHC I and if they can't find it they know something is wrong. If natural killer cells find cells with a changed surface, they dissolve them using cell poisons, also called cytotoxins (granzymes and perforin)
Describe the process of phagocytosis and its contributions to immunity
On a macrophage there are PRR's called toll-like receptor recognize PAMP on the bacteria/virus and binds to it which activates the immune response. The pathogen then gets englufed into the macrophage and a vesicle forms which chops up the pathogen. Phagolysosome breaks down the cell and is killed. The macrophage then does 3 things. 1) releases cytokines and chemokines which cause inflammation and recruits neutrophils. 2) Th cell comes over and binds to antigen presenting cell which activates B cells and Tc cells. 3) eliminates pathogen through exocytosis
Fermentation
Organic molecule is the final E- acceptor Glycolysis 2 ATP
- Give an example of passive immunity acquired naturally, passive immunity acquired artificially, active immunity acquired naturally, and active immunity acquired artificially.
Passive immunity acquired naturally- through placenta (mom to baby) Passive immunity acquired aritficially - antitetanus injection Active immunity acquired naturally- catching a cold active immunity acquired artificially- vaccination
Passive immunity
Passive immunity is due to antibodies that are produced in a body other than your own. Infants have passive immunity because they are born with antibodies that are transferred through the placenta from their mother. These antibodies disappear between ages 6 and 12 months.
how do you control microbial growth- physical and chemical methods
Physical Methods- Dry heat like direct flaming, autoclaving, pasteurization (moist heat), radiation Chemical Methods- chemicals and gases, disinfection, sanitization
Gram- negative
Plasma membrane Thin peptidoglycan, outermembrane (lipopolysaccharide)
Gram-positive
Plasma membrane, Thick peptidoglycan, purple
Translation
RNA--> protein using Ribosomes
Describe why individuals choose not to vaccinate and strategize how to talk to them
Religious reasons, believe it will cause autism. Tell real life stores, show pictures
Central Dogma
Replication, Transcription, Translation DNA--> RNA--> Protein
Obligate aerobe
Requires O2
Extreme halophile
Requires high concentrations (10% or greater) of salt to grow. May grow optimally at salt concentrations greater than 20%.
microaerophiles
Requires low concentration of O2
Halotolerant
Requires salt to grow. Will not grow in media which has 0% salt. This term can be broad (referring to organisms that could grow optimally at concentrations anywhere from 3-20% NaCl), but many halophiles that are of medical concern can grow optimally in media with 3.5% NaCl (the concentration of NaCl in saltwater.
What bacteria causes Typhoid Fever?
Salmonella typhi
B cell receptor
which allows a B cell to detect when a specific antigen is present in the body and triggers B cell activation.
What type of vaccination is used for typhoid fever?
Subunit vaccine, oral capsule
Superantigen
Superantigens (SAgs) are microbial products that have the ability to promote massive activation of immune cells (T cells), leading to the release of inflammatory mediators that can ultimately result in hypotension, shock, organ failure and death. SAgs are produced by some pathogenic viruses and bacteria most likely as a defense mechanism against the immune system.
What type of Syphilis causes damage to your brain, nerves, eyes, heart, blood vessels, liver, bones and joints?
Tertiary Syphilis Syphilis is a sexually transmitted infection caused by treponema pallidum
Explain the process by which a macrophage that has bound a bacterial pathogen is activated (or licensed) by a TH cell.
Th cell activates macrophage by releasing cytokines and speeds up the process of phagocytosis by macrophages
Zone of inhibition
The area around a chemically soaked paper disk where growth is inhibited.
What is the morphology of the bacteria that causes Syphilis?
The bacteria that causes Syphilis is a spirochete. This means that it is corkscrew shaped.
Explain how quorum sensing benefits the bobtail squid.
The bobtail squid is active at night and has a symbiotic relationship with Vibrio fischeri. The bacteria illuminate the underside of the squid so that it does not cast a shadow on the sea floor at night, thus masking it from predators.
Describe how antibiotics may be able to help treat Lyme disease?
The days to take the antibiotic are around the same length for adults and children. Treatment for Late-Stage Lyme Disease Instead of receiving oral antibiotics the difference is that the medicine will be given to you directly into a vein (IV)
Horizontal Gene transfer
The exchange of genetic information on one bacterial cell to another bacterial cell
Humoral immunity
The humoral response (or antibody‐mediated response) involves B cells that recognize antigens or pathogens that are circulating in the lymph or blood The response follows this chain of events: Antigens bind to B cells. Interleukins or helper T cells costimulate B cells. In most cases, both an antigen and a costimulator are required to activate a B cell and initiate B cell proliferation. B cells proliferate and produce plasma cells. The plasma cells bear antibodies with the identical antigen specificity as the antigen receptors of the activated B cells. The antibodies are released and circulate through the body, binding to antigens. B cells produce memory cells. Memory cells provide future immunity.
Minimal Inhibitory Concentration
The lowest concentration of an antimicrobial agent that will inhibit its growth The larger the number the number the larger the area. The larger the zone of inhibition the more succesful, so the smaller the number the more succesful A lower MIC value indicates that less drug is required for inhibiting growth of the organism; therefore, drugs with lower MIC scores are more effective antimicrobial agents.
Describe what would happen if a bacterium encoding the lux gene obtained a nonsense mutation in the cell-surface receptor recognizing the autoinducer?
The lux gene is a quorum sensing gene for luminescense. If a bacterium had a nonsense mutation in the autoinducer receptor, it likely would not bind the autoinducers from nearby cells, preventing activation of lux transcription. This would prevent the bacterial cell from becoming luminescent.
MHC II
The main function of major histocompatibility complex (MHC) class II molecules is to present processed antigens, to CD4(+) Th-cells
Draw the basic structure of an antibody. Label the Fc and variable regions. Which region binds an antigen?
The variable region
