Microbiology Final Exam
Pili
(singular, pilus) Long, tubular structures made of piling protein produced by gram- negative bacteria and used for conjugation.
IgE
a type of protein in the body called an antibody. As part of the immune system, it plays a role in allergic reactions.
Phage
A bacteriophage; a virus that specifically parasitizes bacteria.
Point mutation
A change that involves the loss, substitution, or addition of one or a few nucleotides.
Covalent bond
A chemical bond formed by the sharing of electrons between two atoms.
Ionic bond
A chemical bond in which electrons are transferred and not shared between atoms.
True pathogens
an infectious agent that causes disease in virtually any susceptible host
Clostridium tetani
an obligate anaerobic bacteria whose spores produce two distinct toxins—tetanolysin, which causes local tissue destruction, and tetanospasmin, which causes clinical tetanus.
Endemic
A native disease that prevails continuously in a geographic region.
Mutation
A permanent inheritable alteration in the DNA sequence or content of a cell.
Lymph node
A small bean-shaped structure that is part of the body's immune system.
Endospore
A small, dormant, resistant derivative of a bacterial cell that germinates under favorable growth conditions into a vegetative cell. The bacterial genera bacillus and clostridium are typical sporeformers.
Candida albicans
A yeast-like fungal organism found in small amounts in the normal human intestinal tract.
Co-factor
An enzyme accessory. It can be organic, such as coenzymes, or inorganic.
Holoenzyme
An enzyme complete with its apoenzyme and cofactors.
Pathogens
Any agents (usually a virus, bacterium, fungus, protozoan, or helminth) that causes disease.
Covalent bonds: Result from sharing electrons, Ionic bonds: Result from transferring electrons, Hydrogen bonds: Are the weakest chemical bonds.
Contrast the four different types of chemical bonds.
Competitive inhibitor
Control process that relies on the ability of metabolic analogs to control microbial growth by successfully competing with a necessary enzyme to halt the growth of bacterial cells.
Bioremediation
Decomposition of harmful chemicals by microbes or consortia of microbes.
The humoral immune system deals with antigens from pathogens that are freely circulating, or outside the infected cells.
Diagram & explain humoral immune response.
On a biological level, the main difference is that bacteria are free-living cells that can live inside or outside a body, while viruses are a non-living collection of molecules that need a host to survive.
Differentiate a virus from a bacterium.
Active immunity
Immunity acquired through direct stimulation of the immune system by antigen.
Inclusion bodies
One of a variety of different storage compartments in bacterial cells.
Electron transport chain
The last step of catabolism.
Diapedesis
The migration of intact blood cells between endothelial cells of a blood vessel such as a venule.
Clonal expansion
The proliferation of B-lymphocytes and T-lymphocytes activated by clonal selection in order to produce a clone of identical cells.
Epidemiology
The study of the factors affecting the prevalence and spread of disease within a community.
Kreb/citric acid cycle
This set of reactions takes place in the cytosol of bacteria and is catalyzed by a group of enzymes.
Chlamydia trichomatis
a common sexually transmitted infection (STI) caused by bacteria.
IgD
a minor class of immunoglobulins including antibodies that are of unknown function except as receptors for antigen.
CD4+ cell
also known as T cells, are white blood cells that fight infection and play an important role in your immune system.
Bacteriocidal
inhibition of the growth of bacteria without destruction.
Antimicrobial peptides
(AMPs) Short protein molecules found in epithelial cells; have the ability to kill bacteria.
Endotoxin
A bacterial toxin that is not ordinarily released (as is exotoxin). Endotoxin is composed of a phospholipid-polysaccharide complex that is an integral part of gram-negative bacterial cell walls. Endotoxins can cause severe shock and fever.
Cytokines
A chemical substance produced by white blood cells and tissue cells that regulates development, inflammation, and immunity.
Phospholipid
A class of lipids that compose a major structural component of cell membranes.
Phagocyte
A class of white blood cells capable of engulfing other cells and particles.
Carbohydrate
A compound containing primarily carbon, hydrogen, and oxygen in a 1:2:1 ratio.
Pandemic
A disease afflicting an increased proportion of the population over a wide geographic area (often worldwide).
Glycocalyx
A filamentous network of carbohydrate-rich molecules that coats cells.
Psychrophile
A microorganism that thrives at low temperature (0°C-20°C), with a temperature optimum of 0°C-15°C.
Hypothesis
A tentative explanation of what has been observed or measured.
Recombination
A type of genetic transfer in which DNA from one organism is donated to another.
Cytotoxic T-cell
A type of immune cell that can kill certain cells, including foreign cells, cancer cells, and cells infected with a virus.
Histiocytes
Another term for macrophage
The six stages are: attachment, penetration, transcription, biosynthesis, maturation, and lysis.
Describe the steps of bacteriophage replication and lysogeny.
Carbohydrates, Lipids, Proteins, Nucleic acids.
Identify the four families of macromolecules and what they are composed of.
Capsid - The capsid is the protein shell that encloses the nucleic acid; Envelope - Many types of virus have a glycoprotein envelope surrounding the nucleocapsid; Spike- a glycoprotein that protrudes from the envelope of some viruses and facilitates entry of the virion into a host cell by binding to a receptor on the surface of a host cell; Nucleic Acid - Just as in cells, the nucleic acid of each virus encodes the genetic information for the synthesis of all proteins.
Identify the major viral structures including: capsid, envelope, spikes and nucleic acid.
two pairs of polypeptide chains (lengths of amino acids linked by peptide bonds) that form a flexible Y shape.
Know in detail the structure of an antibody molecule.
Pressurized steam at 120° for 20-30 minutes.
List any ways in destroying the endospore.
Methanogens
Methane producers.
Agranulocytes
One form of leukocyte (white blood cell) having globular, non lobed nuclei and lacking prominent cytoplasmic granules.
Aerobic respiration
Respiration in which the final electron acceptor in the electron transport chain is oxygen.
Passive immunity
Specific resistance that is acquired indirectly by donation of preformed immune substances (antibodies) produced in the body of another individual.
Septicemia
Systemic infection associated with microorganisms multiplying in circulating blood.
Agglutination
The aggregation by antibodies of suspended cells or similar size- particles (agglutinogens) into clumps that settle.
Variable regions
The antigen-binding fragment of an immunoglobulin molecule, consisting of a combination of heavy and light chains whose molecular conformation is specific for the antigen.
Nucleoid
The basophilic nuclear region or nuclear body that contains the bacterial chromosome.
Apoenzyme
The protein part of an enzyme, as opposed to the nonprotein or inorganic cofactors.
Substrates
The specific molecule upon which an enzyme acts.
Oxidative phosphorylation
The synthesis of ATP using energy given off during the electron transport phase of respiration.
Chemotaxis
The tendency of organisms to move in response to a chemical gradient (toward an attractant or to avoid adverse stimuli)
Chemotaxis
The tendency of organisms to move in response to a chemical gradient (toward an attractant or to avoid adverse stimuli.)
Myth 1: Vaccines contain many harmful ingredients; Fact: Vaccines contain ingredients that allow the product to be safely administered.
Understand the benefits, hazards, and myths about vaccination.
Cluster of differentiation molecules
a protocol used for the identification and investigation of cell surface molecules providing targets for immunophenotyping of cells.
Biocide
a substance that destroys living things, especially a pesticide, fungicide, or herbicide.
Vibrio
a waterborne bacterium of a group that includes some pathogenic kinds that cause cholera, gastroenteritis, and septicemia.
Opsonin
an antibody or other substance which binds to foreign microorganisms or cells making them more susceptible to phagocytosis.
Innate immunity
the first part of the body to detect invaders such as viruses, bacteria, parasites and toxins, or to sense wounds or trauma.
Antigen
(Ag) Any cell, particle, or chemical that induces a specific immune response by B cells or T cells and can stimulate resistance to an infection or a toxin.
B-cell
(B lymphocyte) A white blood cell that gives rise to plasma cells and antibodies.
B-cells
(B lymphocyte) A white blood cell that gives rise to plasma cells and antibodies.
Hypervariable region
(HVR) is a location within nuclear DNA or the D-loop of mitochondrial DNA in which base pairs of nucleotides repeat (in the case of nuclear DNA) or have substitutions (in the case of mitochondrial DNA).
HIV
(Human Immunodeficiency Virus) A retrovirus that causes acquired immunodeficiency syndrome (AIDS)
Interferon
(IFN) Natural human chemical that inhibits viral replication; used therapeutically to combat viral infections and cancer.
Immunoglobulin
(Ig) The chemical class of proteins to which antibodies belong.
Natural killer cell
(NK) Cells that are derived directly from lymphoid stem cells that do no have specific antigen receptors and directly from lymphoid stem cells that do not have specific antigen receptors and directly attack and kill virus-infected and cancer cells.
Natural killer cells
(NK) Cells that are derived directly from lymphoid stem cells that do no have specific antigen receptors and directly from lymphoid stem cells that do not have specific antigen receptors and directly attack and kill virus-infected and cancer cells.
Reverse transcriptase
(RT) the enzyme possessed by retroviruses that carries out the reversion of RNA to DNA- a form of reverse transcription.
T-cells
(T lymphocyte) A white blood cell that is processed in the thymus and is involved in cell-mediated immunity.
FAb
(fragment antigen-binding) is a region on an antibody that binds to antigens.
Fc
(fragment crystallizable region) is the tail region of an antibody that interacts with cell surface receptors called Fc receptors and some proteins of the complement system.
GALT
(gut-associated lymphoid tissue) A collection of lymphoid tissue in the gastrointestinal tract that includes the appendix, the lacteals, and Peyer's patches.
Nosocomial infection
(healthcare-associated infection) Any infection acquired as a direct result of a patient's presence in a hospital or health care setting.
PAMPs
(pathogen-associated molecular patterns) Molecules on the surfaces of many types of microbes that are not present on host cells that mark the microbes as foreign.
Prokaryotic
any organism that lacks a distinct nucleus and other organelles due to the absence of internal membranes.
T-helper cells
A class of thymus-stimulated lymphocytes that facilitate various immune activities such as assisting B cells and macrophages.
Spirochete
A coiled, spiral-shaped bacterium that has endoflagella and flexes as it moves.
Theory
A collection of statements, propositions, or concepts that explain or account for a natural event.
Biofilm
A complex association that arises from a mixture of microorganisms growing together on the surface of a habitat.
Co-enzyme
A complex organic molecule, several of which are derived from vitamins. A coenzyme operates in conjunction with an enzyme. Coenzymes serve as transient carries of specific atoms or functional groups during metabolic reactions.
Asepsis
A condition free of viable pathogenic microorganisms.
Clostridium botulinum
A group of gram-positive, rod-shaped bacteria commonly found in the soil that grow best in anaerobic (in the absence of oxygen) conditions.
Prostaglandins
A hormone like substance that regulates many body functions. Prostaglandin comes from a family of organic acids containing 5-carbon rings that are essential to the human diet.
Monocytes
A large mononuclear leukocyte normally found in the lymph nodes. Spleen, bone marrow, and loose connective tissue. This type of cell makes up 3% to 7% of circulating leukocytes.
Antibody
A large protein molecule evoked in response to an antigen that interacts specifically with that antigen.
Dendritic cell
A large, antigen-processing cell characterized by long, branchlike extensions of the cell membrane.
Eosinophils
A leukocyte whose cytoplasmic granules readily stain with red eosin dye.
Microorganisms
A living thing ordinarily too small to be seen without magnification, an organism of microscopic size.
Neutrophils
A mature granulocyte present in peripheral circulation, exhibiting a multilobular nucleus and numerous cytoplasmic granules that retain a neutral stain. The neutrophil is an active phagocytic cell in bacterial infection.
Granulocytes
A mature leukocyte that contains noticeable granules in a Wright stain.
Eukaryotic
A member of the domain eukaryotic whose cells have a well-defined nucleus and membrane-bound organelles; includes plants, animals, fungi, protozoa, and algae.
Ames test
A method for detecting mutagenic and potentially carcinogenic agents based upon the genetic alteration of nutritionally defective bacteria.
Saprophyte
A microbe that decomposes organic remains from dead organisms.
Autotroph
A microorganism that requires only inorganic nutrients and whose sole source of carbon is carbon dioxide.
Thermophile
A microorganism that thrives at a temperature of 50°C or higher.
Barophiles
A microorganism that thrives under high (usually hydrostatic) pressure.
Lipopolysaccharide
A molecular complex of lipid and carbohydrate found in the bacterial cell wall. The lipopolysaccharide (LSP) of gram-negative bacteria is an endotoxin with generalized pathologic effects such as fever.
Basophils
A motile polymorphonuclear leukocyte tha binds IgE. The basophilic cytoplasmic granules contain mediators of anaphylaxis and atopy.
Syncytia
A multinucleate protoplasmic mass formed by consolidation of individual cells.
Spontaneous mutation
A mutation in DNA caused by random mistakes in replication and not known to be influenced by any mutagenic agent. These mutations give rise to an organism's natural, or background, rate of mutation.
Missense mutation
A mutation in which a change in the DNA sequence results in a different amino acid being incorporated into a protein, with varying results.
Nonsense mutation
A mutation that changes an amino-acid-producing codon into a stop codon, leading to premature termination of a protein.
Back mutation
A mutation that counteracts an earlier mutation, resulting in the restoration of the original DNA sequence.
Silent mutation
A mutation that, because of the degeneracy of the genetic code, results in a nucleotide change in both the DNA and mRNA but not the resultant amino acid and, thus, not the protein.
Inflammation
A natural, nonspecific response to tissue injury that protects the host from further damage. It stimulates immune reactivity and blocks the spread of an infectious agent.
Electron
A negatively charged subatomic particle that is distributed around the nucleus in an atom.
Peptidoglycan
A network of polysaccharide chains cross-linked by short peptides that forms the rigid part of bacterial cell walls. Gram-negative bacteria have a smaller amount of this rigid structure that do gram-positive bacteria.
Mast cell
A nonmotile connective tissue cell implanted along capillaries, especially in the lungs, skin, gastrointestinal tract, and genitourinary tract. Like a basophil, its granules store mediators of allergy.
Ribozyme
A part of an RNA-containing enzyme in eukaryotes that removes intervening sequences of RNA called introns and splices together the true coding sequences(axons) to form a mature messenger RNA.
Excision repair
A process whereby cells remove part of a damaged DNA strand and replace it through DNA synthesis using the undamaged strand as a template.
Plasma cell
A progeny of an activated B cell that actively produces and secretes antibodies.
Enzymes
A protein biocatalyst that facilitates metabolic reactions.
Parasitism
A relationship between two organisms in which the host is harmed in some way, while the colonizer benefits.
Major histocompatibility complex (MHC)
A set of genes in mammals that produces molecules on surfaces of cells that differentiate among different individuals in the species.
Neisseria gonorrhoeae
A sexually transmitted infection commonly manifested by urethritis, cervicitis, proctitis, salpingitis, or pharyngitis. Infection may be asymptomatic.
Fimbriae
A short, numerous-surface appendage on some bacteria that provides adhesion but not locomotion.
Gene
A site on a chromosome that provides information for a certain cell function. A specific segment of DNA that contains the necessary code to make a protein or RNA molecule.
Toxin
A specific chemical product of microbes, plants, and some animals that is poisonous to other organisms.
Coccus
A spherical-shaped bacterial cell.
Autoclave
A sterilization chamber that allows the use of steam under pressure to sterilize materials. The most common temperature/pressure combination for an autoclave is 121° and 15 psi.
Flagella
A structure that is used to propel the organism through a fluid environment.
Catalyst
A substance that alters the rate of a reaction without being consumed or permanently changed by it. In cells, enzymes are catalysts.
Pyrogen
A substance that causes a rise in body temperature. It can come from pyrogenic microorganisms or from polymorphonuclear leukocytes (endogenous pyrogens)
Epidemic
A sudden and simultaneous outbreak or increase in the number of cases of disease in a community.
Exotoxin
A toxin (usually protein) that is secreted and acts upon a specific cellular target. Examples: botulin, tetanospasmin, diphtheria toxin, and erythrogenic toxin.
Phagocytosis
A type of endocytosis in which the cell membrane actively engulfs large particles or cells into vesicles.
Antigen presenting cell
A type of immune cell that boosts immune responses by showing antigens on its surface to other cells of the immune system.
Acquired immunity
A type of immunity that develops when a person's immune system responds to a foreign substance or microorganism, or that occurs after a person receives antibodies from another source.
Hydrogen bond
A weak chemical bond formed by the attraction of forces between molecules or atoms- in this case, hydrogen and either oxygen or nitrogen. In this type of bond, electrons are not shared, lost, or gained.
Macrophages
A white blood cell derived from a monocyte that leaves the circulation and enters tissues. These cells are important in nonspecific phagocytosis and in regulating, stimulating, and cleaning up after immune responses.
Microaerophile
An aerobic bacterium that requires oxygen at a concentration lass than that in the atmosphere.
Bacteriostasis
An agent that kills bacteria.
Neutron
An electrically neutral particle in the nuclei of all atoms except hydrogen.
Proton
An elementary particle that carries a positive charge. It is identical to the nucleus of the hydrogen atom.
Viroids
An infectious agent that, unlike a vision, lacks a capsid and consists of a closed circular RNA molecule. Although known viroids are all plant pathogens, it is conceivable that animal versions exist.
Zoonosis
An infectious disease indigenous to animals that humans can acquire through direct or indirect contact with infected animals.
Psychrotroph
An organism that grows best at cold temperatures.
Heterotroph
An organism that relies upon organic compounds for its carbon and energy needs.
Commensalism
An unequal relationship in which one species derives benefit without harming the other.
Induced mutation
Any alteration in DNA that occurs as a consequence of exposure to chemical or physical mutagens.
Hemolysins
Any biological agent that is capable of destroying red blood cells and causing the release of hemoglobin. Many bacterial pathogens produce exotoxins that act as hemolysis.
Sterilization
Any process that completely removes or destroys all viable microorganisms, including viruses, from an object or habitat. Material so treated is sterile.
Moist heat is generally more effective than dry heat for killing microorganisms because of its ability to penetrate microbial cells. Moist heat kills microorganisms by denaturing their proteins (causes proteins and enzymes to lose their three-dimensional functional shape).
Compare the effectiveness of moist heat and dry heat on microbial control.
Enveloped virus
Composed of a nucleocapsid surrounded by a flexible membrane called an envelope.
Toxemia
Condition in which a toxin (microbial or otherwise) is spread throughout the bloodstream.
Bacterial growth is the division of one bacterium into two daughter cells in a process called binary fission.
Define bacterial growth, including binary fission.
The most common type of nosocomial infections are surgical wound infections, respiratory infections, genitourinary infections, as well as gastrointestinal infections.
Define nosocomial infection and the 3 most common methods of transmission.
STERILIZATION: removing all microbial life; DISINFECTION: removing pathogens; ANTISEPSIS: removing pathogens from living tissue; DEGERMING: removing microbes from a limited area; SANITIZATION: lowering microbial counts on eating utensils; BIOCIDE/GERMICIDE: killing microbes; BACTERIOSTASIS: inhibiting, not killing microbes; ASPESIS: absence of significant contamination
Define the following key terms related to microbial control: sterilization, disinfection, antisepsis, degerming, sanitization, biocide, germicide, bacteriostasis, and asepsis.
Autotrophs: Make their own food, make organic compounds from CO2 and thius need not acquire carbon from other organic organisms; Heterotrophs: Catabolize reduced organic molecules, such as proteins, carbs, amino acids, and fatty acids that acquire from other organisms; Chemotrophs: Acquire energy from redox reactions involving inorganic and organic chemicals. These reactions can be aerobic, anaerobic or fermentation depending on the final electron acceptor; Phototrophs: Organisms that use light as their energy source.
Define the nutritional categories of microbes based on their energy source and carbon source.
There are four distinct phases of the growth curve: lag, exponential (log), stationary, and death. The initial phase is the lag phase where bacteria are metabolically active but not dividing. The exponential or log phase is a time of exponential growth. In the stationary phase, growth reaches a plateau as the number of dying cells equals the number of dividing cells. The death phase is characterized by an exponential decrease in the number of living cells.
Define the stages of growth on a microbial growth curve.
The T and B lymphocytes (T and B Cells) are involved in the acquired or antigen-specific immune response given that they are the only cells in the organism able to recognize and respond specifically to each antigenic epitope.
Describe B and T cell lymphocytes and identify where each one matures.
DNA gyrase relaxes the supercoil ahead of the replication fork. DNA ligase makes covalent bonds to join DNA strands: Okazaki fragments, and new segments in excision repair. DNA polymerase synthesizes DNA and proofreads it to make sure the base pairs are properly matched up and repairs them if not.
Describe DNA replication, including the functions of DNA gyrase, DNA ligase, and DNA polymerase.
These organisms have enzymes which neutralize the toxic forms of oxygen. metabolic need is not absolute-that is, they can ferment if there is no oxygen around. Possess enzymes to neutralize toxic forms of oxygen, therefore they can live in the presence of oxygen.
Describe how aerobic bacteria avoid damage from toxic forms of oxygen.
Enzymes can be regulated by other molecules that either increase or reduce their activity.
Describe how enzymes are controlled.
In eukaryotes, most cellular respiration reactions take place within the mitochondria. In prokaryotes, they occur in the cytoplasm and/or within the cell membrane.
Describe how eukaryotic and prokaryotic cellular respiration differ.
Coccus(circular), Bacillus(Rod), Spirillum(spiral), there are more less common shapes.
Describe the 3 major shapes of prokaryotes. Are there any more unusual shapes of prokaryotes?
Anatomical and physiological barriers provide the crucial first line of defense against pathogens. These barriers include intact skin, vigorous mucociliary clearance mechanisms, low stomach pH and bacteriolytic lysozyme in tears, saliva and other secretions.
Describe the body's anatomical, physiological and endocytic barriers against infection.
The complement system activates through a triggered-enzyme cascade. In such a cascade, an active complement enzyme generated by cleavage of its zymogen precursor then cleaves its substrate, another complement zymogen, to its active enzymatic form.
Describe the complement system/complement cascade. How is it activated? What are the effects following activation?
Phase 1: Vegetative cells- Metabolically active and growing, can be induced by the environment to undergo sporulation; Phase 2: Endospore formation- Metabolically active and growing, can be induced by the environment to undergo sporulation.
Describe the cycle of Sporulation in all of its stages, and why this aids the endospore to last as long as it does.
Antimicrobial agents cause damage to the lipids or proteins of the plasma membrane(permeability) and causes cellular contents to leak into the surrounding medium and interferes with the growth of the cell; damage to nucleic acids by heat, radiation, or chemicals is lethal to cell; the cell can no longer replicate or carry out normal metabolic functions- synthesis of enzymes
Describe the effects of microbial control agents on specific cellular structures.
A fever fights infection by helping immune cells to crawl along blood-vessel walls to attack invading microbes.
Describe the fever response and describe how the fever response is protective.
Extracellular digestion is a process in which animals feed by secreting enzymes through the cell membrane onto the food; Passive transport is defined as movement of a solute from a region of high electrochemical potential on one side of the cell membrane to a region of lower electrochemical potential on the opposite side; Active transport is the process of moving molecules across a cellular membrane through the use of cellular energy.
Describe the mechanisms used by microbes to bring nutrients into the cell including: extracellular digestion, passive transport and active transport.
Enzymes are made up of protein that speed up chemical reactions by lowering energy barriers; Specific for their substrates and lower the energy of activation needed to cause a reaction; The substrate is converted to products, the products are released, and the enzyme reverts back to its original form, ready to take new substrates; Certain chemicals inhibit the functions of enzymes.
Describe the physical makeup, biological activity, environmental sensitivity and regulation of activity for enzymes.
Attachment = bacteriophages contain fibers at the tail that attach to the complementary receptor on the host cell surface; Entry = Virus tail releases phage lysozyme which breaks down a portion of the bacterial/host cell wall, so that the virus can inject its DNA into the cell; Uncoating = capsid is removed, separation of viral nucleic acid from protein coat; Biosynthesis = virus-induced degradation of host DNA, virus begins to use host DNA to make their own DNA and proteins; Maturation = viral DNA and capsid form complete virions; Release of virus = lysis (Lysozyme released which breaks down host cell wall so virions can be released)
Describe the principal events of attachment, entry, uncoating, biosynthesis, maturation, and release of an enveloped DNA-containing virus.
The clonal selection hypothesis is a widely accepted model for the immune system's response to infection.
Describe the process of clonal selection and explain how this provides specificity and memory for the adaptive immune response.
The formation of a biofilm involves a four step process: attachment of bacterial cells to a surface, accumulation of bacterial cells forming multiple layers, maturation of the biofilm, and release of some bacteria in the planktonic state; Bacterial biofilm is a key reason for the contamination of medical devices and the generation of microbial and chronic infections in the body.
Describe the steps in creating a biofilm and its medical significance.
In the absence of oxygen in some cell types, fermentation allows the reduction of pyruvate to lactate and the reoxidation of NADH to NAD+. The regeneration of NAD+ allows glycolysis to continue to make ATP by substrate level phosphorylation. Credit:
Describe the strategies cells use for metabolizing sugars in the absence of O2.
The structure of ATP is a nucleoside triphosphate, consisting of a nitrogenous base (adenine), a ribose sugar, and three serially bonded phosphate groups. ATP captures chemical energy obtained from the breakdown of food molecules and releases it to fuel other cellular processes.
Describe the structure of ATP and its metabolic role as an energy carrier.
Erythema (redness), edema (swelling), heat, pain, and altered function.
Describe the symptoms of an inflammatory response and the major cells and molecules involved in inflammation and fever.
Monotrichous
Describing a microorganism that bears a single flagellum.
Lophotrichous
Describing bacteria having a tuft of flagella at one or both poles.
Cell-mediated immunity (CMI) is an immune response that does not involve antibodies but rather involves the activation of macrophages and NK-cells, the production of antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen .
Diagram & explain cell-mediated immunity.
In transformation, a bacterium takes up a piece of DNA floating in its environment. In transduction, DNA is accidentally moved from one bacterium to another by a virus. In conjugation, DNA is transferred between bacteria through a tube between cells.
Differentiate modes of horizontal gene flow (conjunction, transformation, and transduction).
Direct contact; Droplet spread. Indirect. Airborne; Vehicleborne; Vectorborne (mechanical or biologic).
Discuss the following routes of transmission of infectious disease agents: Airborne, Contact, Vector-borne, Vehicle-borne, Direct, Indirect
Live virus vaccines use the weakened (attenuated) form of the virus. The measles, mumps, and rubella (MMR) vaccine and the varicella (chickenpox) vaccine are examples. Killed (inactivated) vaccines are made from a protein or other small pieces taken from a virus or bacteria.
Discuss the pros and cons of killed vs attenuated vaccines.
The electron transport chain is the final and most important step of cellular respiration. While Glycolysis and the Citric Acid Cycle make the necessary precursors, the electron transport chain is where a majority of the ATP is created. It has an important role in both photosynthesis and cellular respiration.
Discuss the significance of the electron transport system.
competitive inhibition is the binding of the inhibitor to the active site of the enzyme whereas noncompetitive inhibition is the binding of the inhibitor to the enzyme at a point other than the active site.
Distinguish between competitive and non-competitive enzyme inhibition.
Certain underlying diseases, procedures, hospital services, and categories of age, sex, race, and urgency of admission were all found to be significant risk factors for nosocomial infection.
Evaluate contributing factors to nosocomial infections.
Without oxygen, organisms can split glucose into just two molecules of pyruvate. This releases only enough energy to make two ATP molecules. With oxygen, organisms can break down glucose all the way to carbon dioxide. This releases enough energy to produce up to 38 ATP molecules.
Explain how ATP molecules are produced in aerobic respiration and why O2 is important to the process.
B cells differentiate into plasma cells that produce antibody molecules closely modeled after the receptors of the precursor B cell. Once released into the blood and lymph, these antibody molecules bind to the target antigen (foreign substance) and initiate its neutralization or destruction.
Explain how B cells recognize antigens, differentiate into plasma cells and secrete specific antibodies.
HIV is called a retrovirus because it works in a back-to-front way. Unlike other viruses, retroviruses store their genetic information using RNA instead of DNA, meaning they need to 'make' DNA when they enter a human cell in order to make new copies of themselves.
Explain how HIV differs from other viruses. What is the difference between HIV and AIDS?
Each T cell has a unique T cell receptor (TCR) that recognizes a specific antigen.TCRs recognize an antigen when they bind with major histocompatibility complex (MHC) molecules on the surface of other cells. There are thousands of TCRs on the surface of a T cell, which increases the chances of the T cell binding with an antigen.
Explain how T cells recognize antigens and differentiate into cytotoxic killer T cells or Helper T cells.
In both electron transport chains, energy carrier molecules are arranged in sequence within a membrane so that energy-carrying electrons cascade from one to another, losing a little energy in each step.
Explain how carrier molecules function in the electron transport chain.
Poliovirus only infects people. It enters the body through the mouth and spreads through: Contact with the feces (poop) of an infected person. Droplets from a sneeze or cough of an infected person (less common). While Influenza spreads from person to person.
Explain how the mode of transmission differs between the influenza virus and the polio virus.
Two regulators turn the operon "on" and "off" in response to lactose and glucose levels: the lac repressor and catabolite activator protein (CAP).
Explain the Lac operon. How is it turned on? Off? Regulated? What happens with mutation?
Herd immunity protects the most vulnerable members of our population. If enough people are vaccinated against dangerous diseases, those who are susceptible and cannot get vaccinated are protected because the germ will not be able to "find" those susceptible individuals.
Explain the principle of herd immunity.
The bacterial cell wall has the ability to retain the dye during the staining process
Explain the significance of the cell wall and cell membrane in relation to Gram Staining.
A widespread occurrence of an infectious disease in a community at a particular time.
Explain what an epidemic is.
Epidemiology is the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems.
Explain what are some of the key characteristics of epidemiology that distinguish it from medicine and other disciplines.
Promoter: The starting site on a DNA strand for transcription of RNA by the RNA polymerase. Terminator: The site on a DNA strand at which transcription ends. mRNA: The type of RNA molecule that directs the incorporation of amino acids into proteins.
Explain what the role of the promoter, terminator, and mRNA in transcription.
Plasmid
Extrachromosomal genetic units characterized by several features, a plasmid is a double- stranded DNA that is smaller Tham and replicates independently of the cell chromosome, it bears genes that are not essential for cell growth, it can bear genes that code for adopted traits; and it is transmissible to other bacteria.
Non-competitive inhibitor
Form of enzyme inhibition that involves binding of a regulatory molecule to a site other than the active site.
In translation, the cell uses an mRNA strand that it has just transcribed from its genetic code as a template to assemble proteins. The cell has just transcribed this mRNA strand from its DNA, and it now translates the mRNA's nucleotide sequence into a chain of amino acids.
Given a DNA template with a promoter sequence generate a mRNA transcript and utilize a codon table to generate an amino acid sequence for the translated peptide.
Anti-toxin
Globulin fraction of serum that neutralizes a specific toxin. Also refers to the specific antitoxin antibody itself.
Amphitrichous
Having a single flagellum or a tuft flagella at opposite poles of a microbial cell.
Pasteurization
Heat treatment of perishable fluids such as milk, fruit juices, or wine to destroy heat-sensitive vegetative cells, followed by rapid chilling to inhibit growth of survivors and germination of spores. It prevents infection and spoilage.
The innate immune system is essentially made up of barriers that aim to keep viruses, bacteria, parasites, and other foreign particles out of your body or limit their ability to spread and move throughout the body.
Identify cells of the innate immune response and describe the ways in which they fight infection.
Enzymes contain a globular protein part called apoenzyme and a non-protein part named cofactor or prosthetic group or metal-ion-activator.
Identify components of an enzyme.
There are four nitrogenous bases in DNA, two purines (adenine and guanine) and two pyrimidines (cytosine and thymine). A-T, C-G
Identify the 4 nucleotide bases, identify if they are purines or pyrimidines, and their complimentary base pair
Psychrophiles (cold-loving microbes), mesophiles (moderate-temperature loving microbes) and thermophiles (heat-loving microbes).
Identify the classifications for bacteria based on temperature range and oxygen requirements.
DNA: is the master control molecule of the cell; RNA: assists DNA in the control of everyday cell function.
Identify the differences and similarities between RNA and DNA.
Cell lysis upon assembly and insertion of the terminal membrane attack complex (MAC), complement mediated opsonization, and the release of anaphylatoxins that enhance local inflammation.
Identify the three outcomes complement fixation (opsonization, cytolysis, inflammation).
A base, sugar, and a phosphate group.
Identify what the 3 components of a nucleotide are.
Operator
In an operon sequence, the DNA segment where transcription of structural genes id initiated.
Peritrichous
In bacterial morphology, having flagella distributed over the entire cell.
Labile
In chemistry, molecules, or compounds that are chemically unstable in the presence of environmental changes.
Adjuvant
In immunology, a chemical vehicle that enhances antigenicity, presumably by prolonging antigen retention at the injection site.
Complement
In immunology, serum protein components that act in a definite sequence when set in motion either by an antigen-antibody complex or by factors of the alternative (properdin) pathway.
Virulence
In infection, the relative capacity of a pathogen to invade and harm host cells.
Okazaki fragments
In replication of DNA, a segment formed on the lagging strand in which biosynthesis is conducted in a discontinuous manner dictated by the 5' -> 3' DNA polymerase orientation.
Nucleocapsid
In viruses, the close physical combination of the nucleic acid with its protective covering.
Operons aren't just made up of the coding sequences of genes. Instead, they also contain regulatory DNA sequences that control transcription of the operon.
Interpret pre-transcriptional control systems of operons.
White blood cells play an important role in the immune system by identifying, destroying, and removing pathogens, damaged cells, cancer cells, and foreign matter from the body. Granulocytes contain granules or sacs in their cytoplasm and agranulocytes do not. Each type of granulocyte and agranulocyte plays a slightly different role in fighting infection and disease.
Know the general functions of the white blood cells. Categorize them as to phagocytes or not; granulocytes or agranulocytes
Parasitism: the microbe benefits at the expense of the host; Mutulaism: both microbe and the host benefit; Commensalism: one of the organism benefits while the other neither experience benefit or harm; Antagonism: one of the organism benefits at he expense of the other; Synergism: is a special type of relationship among organisms in which both of them work together, it may be beneficial and it may be harmful.
List and describe the 5 types of associations microbes can have with their host.
One of the most common portals of entry is the mucous membranes, especially those of the respiratory, gastrointestinal, and urogenital tracts. Another important portal of entry is the skin.
List common entry sites for pathogens and explain why most infections begin at these sites.
Mechanical barriers — which include the skin , mucous membranes , and fluids such as tears and urine — physically block pathogens from entering the body. Chemical barriers — such as enzymes in sweat , saliva , and semen — kill pathogens on body surfaces.
List physical and chemical barriers to microbial invasion.
Gram +: Stains purple, 2 layers in the cell wall(lacks outer membrane), Thick peptidoglycan; Gram -: Stains pink, 3 layers in the cell wall(membrane), Thin peptidoglycan.
List the differences between Gram + and Gram - cells.
There are two major types of T cells: the helper T cell and the cytotoxic T cell. As the names suggest helper T cells 'help' other cells of the immune system, whilst cytotoxic T cells kill virally infected cells and tumors.
List the major types of cells that T-cells will differentiate into. What are main functions of these types of cells?
Input for the breakdown of 1 glucose molecule in glycolysis is 2 ATP and the output is 4 ATP, 2 NADH and 2 pyruvate molecules. Metabolic pathway which provides anaerobic source of energy in all organisms is glycolysis.
List the net input and output molecules and the cellular locations for glycolysis, the tricarboxylic acid cycle/Kreb cycle and the electron transport chain in prokaryotes.
The ability to use motility and other means to contact host cells and disseminate within a host; The ability to adhere to host cells and resist physical removal; The ability to invade host cells; The ability to compete for iron and other nutrients.
List virulence factors.
Oncovirus
Mammalian virus capable of causing malignant tumors.
Aseptic technique
Methods of handling microbial cultures, patient specimens, and other sources of microbes in a way that prevents infection of the handler and others who may be exposed.
Phototroph
Microbes that use photosynthesis to feed.
Trace element
Micronutrients (zinc, nickel, and manganese)that occur in small amounts and are involved in enzyme function and maintenance of protein structure.
Mesophile
Microorganisms that grow at intermediate temperatures.
Virus
Microscopic acellular agent composed of nucleic acid surrounded by a protein coat.
Obligate aerobe
Must have oxygen to grow.
Chemotroph
Organism that oxidizes composunds to feed on nutrients.
Mutualism
Organisms living in an obligatory but mutually beneficial relationship.
Vaccine
Originally used in reference to inoculation with the cowpox or vaccinia virus to protect against smallpox. In general, the term now pertains to injection of whole microbes (killed or attenuated), toxoids, or parts of microbes as a prevention or cure for disease.
Pyogenic
Pertains to pus formers, especially the pyogenic cocci: pneumococci, streptococci, staphylococci, and neisseriae.
Lithoautotroph
Play an important part in recycling inorganic nutrients.
Protein
Predominant organic molecule in cells, formed by long chains of amino acids.
Translation
Protein synthesis; the process of decoding the messenger RNA code into a polypeptide.
Ionizing radiation
Radiant energy consisting of short-wave electromagnetic rays (X ray) or high-speed electrons that cause dislodgment of electrons on target molecules and create ions.
Antigen binding sites
Specific region at the ends of the antibody molecule that recognizes specific antigens. These sites have numerous shapes to fit a wide variety of antigens.
Immunocompetence
The ability of the body to recognize and react with multiple foreign substances.
Abiogenesis
The belief in spontaneous generation as a source of life.
Catabolism
The chemical breakdown of complex compounds into simpler units to be used in cell metabolism.
Synergism
The coordinated or correlated action by two or more drugs or microbes that results in a heightened response or greater activity.
Peptide bond
The covalent union between two amino acids that forms between amine group of one and the carboxyl group of the other. The basic bond of proteins.
Disinfection
The destruction of pathogenic non sporulating microbes or their toxins, usually on inanimate surfaces.
Denitrification
The end of the nitrogen cycle when nitrogen compounds are returned to the reservoir in the air.
Anabolism
The energy-consuming process of incorporating nutrients into protoplasm through biosynthesis.
Glycolysis
The energy-yielding breakdown(fermentation) of glucose to pyretic or lactic acid. It is often called anaerobic glycolysis because no molecular oxygen is consumed in the degradation.
Infection
The entry, establishment, and multiplication of pathogenic organisms within a host.
Fermentation
The extraction of energy through anaerobic degradation of substrates into simpler, reduced metabolites. In large industrial processes, fermentation can mean any use of microbial metabolism to manufacture organic chemicals or other products.
Lysogeny
The indefinite persistence of bacteriophage DNA in a host without bringing about the production of virions.
Denaturation
The loss or normal characteristics resulting from some molecular alteration. Usually in reference to the action of heart or chemicals on proteins whose function depends upon an unaltered tertiary structure.
Normal biota
The native microbial forms that an individual harbors
Morbidity rate
The number of persons afflicted with an illness under question or with illness in general, expressed as a numerator, with the denominator being some unit of population (as in x/100,000).
Mortality rate
The number of persons who have died as the result of a particular cause or due to all causes, expressed as a numerator, with the denominator being some unit of population (as in x/100,000).
Antisepsis
The practice of using antiseptics to eliminate the microorganisms that cause disease.
Bacteremia
The presence of viable bacteria in circulating blood.
Hematopoiesis
The process by which the various types of blood cells are formed, such as in the bone marrow.
Hydrophilic
The property of attracting water. Molecules that attract water to their surface are called hydrophilic.
Hydrophobic
The property of repelling water. Molecules that repel water are called hydrophobic.
Capsid
The protein covering of a virus's nucleic acid core. Capsids exhibit symmetry due to the regular arrangement of subunits called capsomers.
Promoter
The protein product of a repressor gene that combines with the operator and arrests the transcription and translation of structural genes.
Repressor
The protein product of a repressor gene that combines with the operator and arrests the transcription and translation of structural genes.
Clonal deletion
The recognition by a single clone of a B or T cell of a foreign antigen.
Active site
The specific region on an apoenzyme that binds substrates. The site for reaction catalysis.
Aerotolerant anaerobe
The state of not utilizing oxygen but not being harmed by it. Halophiles- A microbe whose growth is either stimulated by salt or requires a high concentration of salt for growth.
Sanitization
To clean inanimate objects using soap and determine agents so that they are safe and free of high levels of microorganisms.
Attenuated vaccine
Vaccines composed of living organisms that have been weakened and cannot cause disease.
Fomite
Virtually any inanimate object an infected individual has contact with that can serve as a vehicle for the spread of disease.
Leukocytes
White blood cells. The primary infection-fighting blood cells.
Streptococcus pneumonia
a bacteria that is commonly found in the nose and throat.
Isotype switching
a biological mechanism that changes a B cell's production of antibody from one class to another.
Methicillin-resistant Staphylococcus aureus (MRSA)
a cause of staph infection that is difficult to treat because of resistance to some antibiotics.
IgA
a class of immunoglobulins including antibodies found in external bodily secretions (such as saliva, tears, and sweat).
IgG
a class of immunoglobulins including the most common antibodies circulating in the blood that facilitate the phagocytic destruction of microorganisms foreign to the body, that bind to and activate complement, and that are the only immunoglobulins to cross over the placenta from mother to fetus.
IgM
a class of immunoglobulins of high molecular weight including the primary antibodies that are released into the blood early in the immune response to be replaced later by IgG and that are highly efficient in binding complement.
CD8+ cell
a critical subpopulation of MHC class I-restricted T cell and are mediators of adaptive immunity
Bacillus
a genus of rod-shaped, gram-positive, aerobic or (under some conditions) anaerobic bacteria widely found in soil and water.
Opportunistic pathogens
a group of microorganisms that do not usually infect healthy hosts but produce infections in hospitals, to immunodepressed persons or those patients presenting underlying diseases as cystic fibrosis, which favors infection (Koch and Hoiby, 1993).
Facultative anaerobe
a microbe that does not require oxygen for its metabolism and is capable of growth in the absence of it.
Cellular immune response
a protective immune process that involves the activation of phagocytes, antigen-sensitized cytotoxic T cells and the release of cytokines and chemokines in response to antigen.
T cell receptor
a protein complex 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.
Inactivated vaccine
composed of dead, or inactivated, viruses and bacteria, and therefore differ from live but attenuated vaccines.
Herd immunity
he status of collective acquired immunity in a population that reduces the likelihood that non immune individuals will contract and spread infection. One aim of vaccination is to induce herd immunity.
Obligate anaerobe
lack the enzymes for processing toxic oxygen.
Transcription
mRNA synthesis; the process by which a strand of RNA is produced against a DNA template.
Prions
proteinaceous infectious particles.
VDJ recombination
the mechanism of somatic recombination that occurs only in developing lymphocytes during the early stages of T and B cell maturation.
Naked virus
the simplest virus, consisting of a geometric capsid assembled around a nucleic acid strand or strands.
Biogenesis
the synthesis of substances by living organisms.
