Micro Test Study Guide

7/30/2019 Micro Test Study Guide

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Test 1 Study Guide Mary-Catherine Ciuba

Chapter 1

What are the ways that microorganisms affect our lives?

What are the two names that make up a scientific name for an organism?

What are the major characteristics of Bacteria, Archaea, Fungi, Protozoa, Algae, and

Viruses?

What are the 3 domains?

What is the cell theory and which scientists contributed to this theory?

Define spontaneous generation and biogenesis.

Identify the contributions to microbiology made by the following scientists:

Needham, Spallanzani, Virchow, Pasteur, Lister, Koch, Jenner, Ehrlich, and Fleming.

Define bacteriology, mycology, parasitology, immunology, and virology.

What are specific ways that microorganisms benefit our lives and environment?

Define normal microbiota and resistance.

List examples of emerging infectious diseases and the specific microorganism that

causes them.

Chapter 10

Define taxonomy, taxon, and phylogeny.

What is the basis of the three domain classification system? How are microorganisms

classified in the three domain system?

What are the characteristics of the Bacteria, Archaea, and Eukarya domains?

What is a scientific name and why are they used?

What is the order of the subdivisions that make up the taxonomic hierarchy? (Figure

10.5)

Define eukaryotic species, prokaryotic species, clone, and strain.

What are the characteristics of prokaryotes and eukaryotes and how do they differ?

What is Protista?

How are viruses classified?

What is the purpose of Bergey’s Manual of Determinative Bacteriology?

Describe how bacteria can be identified using the following methods: Biochemical

tests, Serological testing, ELISA, Western blotting, Flow cytometry, DNA

fingerprinting, PCR, Nucleic acid hybridization, and Southern blotting.

What are dichotomous keys and cladograms?

Chapter 3

What are the metric units of measurement that are used for microorganisms? (Table

3.1)

What are the principle parts of the compound light microscope and their functions?



Describe the path of light as it travels through a compound microscope.

Define resolution.

What is the difference between the following types of microscopes: Compound light,

Darkfield, Phase-contrast, Fluorescence, Confocal, Two-Photon (TPM), Scanning

Acoustic (SAM), Electron, Transmission Electron (TEM), and Scanning Electron

(SEM).

What are the steps of the Gram stain?

What is the purpose of fixing an organism to the slide?

What is negative staining?

Define simple stain and mordant.

What are the primary purposes of the simple, acid-fast, endospore, and flagella

stains?

Chapter 4

How do the cell structures of prokaryotes and eukaryotes differ?

What are the basic shapes of bacteria?

What are the structures and functions of the following external components to the

prokaryotic cell wall: Glycocalyx, Flagella, Axial Filaments, Fimbriae, and Pili?

What are the major functions of the bacterial cell wall?

How do the cell walls of gram-positive and gram-negative bacteria differ?

Given the differences between the gram-positive and gram-negative cells walls, what

is the mechanism of the Gram stain?

What is the structure and function of the prokaryotic plasma membrane?

What is the difference between simple diffusion, facilitated diffusion, and active

transport?

Define osmosis, isotonic, hypotonic, and hypertonic solution.

What is the purpose of endospores, sporulation, and endospore germination?

What is the function of the Nucleus, ER, Golgi complex, Lysosomes, Vacuoles,

Mitochondria, Chloroplasts, Peroxisomes, and Centrosome?

What is the endosymbiotic theory?

Chapter 5

Define metabolism, catabolism, and anabolism.

What are the components of an enzyme?

What are the mechanisms of enzymatic action?

What factors affect enzymatic activity?

How are enzymes named?



What are the differences between competitive, noncompetitive, and feedback

inhibition?

Define oxidation and reduction.

What 3 types of phosphorylation reactions generate ATP? What steps are involved in

each type of reaction?

What is the purpose of Glycolysis, the Krebs cycle, and the electron transport chain?

(What are the beginning and end products?)

What is the difference between aerobic and anaerobic respiration?

Define chemiosmosis.

Generally speaking, what is fermentation and photosynthesis?

What is meant by phototroph, chemotroph, autotroph, and heterotroph?




Chapter 6

What are the 5 groups that classify microorganisms based on their temperature

requirements? What temperature ranges do they grow best? (Fig. 6.1)

What are acidophiles, extreme halophiles, obligate halophiles, and facultative

halophiles?

Describe how microorganisms are classified based on their different oxygen

requirements.

What are the components of chemically defined, complex, and reducing media?

What is the difference between selective, differential, and enrichment media?

How would you obtain a pure culture of a particular bacterium?

Define generation time.

What are the different phases of microbial growth? How do they relate to growth

rate?

What are the 4 direct methods of measuring cell growth?

What are the 3 indirect methods of measuring cell growth?

Chapter 7

Define the following: sterilization, disinfection, antisepsis, sanitization, and

bacteriostasis.

What is the pattern or rate of microbial death after treatment with an anti-microbial

agent?

What factors influence the effectiveness of antimicrobial agents?

What effects do anti-microbial agents have on cellular structures?

Describe how the following methods suppress microbial growth: autoclave,

pasteurization, dry heat, filtration, low temperatures, high pressure, dessication,

osmotic pressure, and radiation. How effective are these methods at controlling or

eliminating microbial growth?

What does the disk-diffusion test measure?

What are the various types of chemical disinfectants and their preferred uses?

Which microorganisms are most resistant/least resistant to chemical biocides? (Fig.

7.11)

Chapter 8

Define genetics, gene, base pairs, genotype, and phenotype.

What is the flow of genetic information in the cell?

What is meant by semiconservative replication?

Describe DNA replication, transcription, and translation. (What is the purpose of

these processes? What steps are involved? Use Fig. 8.3, 8.5, 8.7, and 8.9 for review.)



What are the functions of the following enzymes: DNA gyrase, DNA ligase, DNA

polymerase, Helicase, and RNA polymerase?

What is meant by the following terms: degeneracy, sense codon, antisense codon,

anticodon, messenger RNA, transfer RNA, intron, and exon?

What are the different types of genetic mutations?

What is a mutagen? Give examples.

What is the purpose of the Ames test?

What is the difference between horizontal and vertical gene transfer?

What are 3 methods of genetic recombination in bacteria?

What is the function of plasmids and transposons?

Chapter 9

Define biotechnology and recombinant DNA technology. Give examples of each.

What is the purpose of site-directed mutagenesis?

What is the purpose of restriction enzymes in nature? How are restriction enzymes

used in the lab?

What are the properties of vectors?

Describe the process of PCR (purpose and steps involved).

What are 5 ways that foreign DNA can be inserted into a cell?

What is a genomic library?

Give examples of therapeutic applications of rDNA technology.

What is the Human Genome Project?

Describe the processes of Southern blotting and DNA fingerprinting.

What are the advantages and disadvantages of rDNA technology?




Chapter 13

What are the general characteristics of viruses?

o Viruses are not considered to be obligatory intracellular parasites because they

require a living host in order to multiply and be active.

o The only have DNA OR RNA. One or the other.

o Contain a protein coat that surrounds the nucleic acid.

o Most viruses only infect specific types of cells in one host.

o Some viruses are enclosed in an envelope or have spikes.

o Host range is determined by specific host attachment sites and cellular factors.

because they have few to no metabolism enzymes.

Define bacteriophage.

o Viruses that infect bacteria.

Describe the chemical and physical structure of enveloped and nonenveloped viruses.

o An enveloped virus is surrounded by a protein coat for protection from the

environment as well as serves as a vehicle of transmission. Viruses that are

not enveloped are still covered to separate nucleic acids and the environment,

but they are not as well protected as the enveloped virus.

Define viral species.

o A group of viruses sharing the same genetic information and ecological niche

(host range)

o *specific epithets are never used for bacteria

o they are described by common names and numbers to indicate subspecies

How are bacteriophages cultured?

o Bacteriophages can be grown either is suspensions of bacteria in liquid media

or in bacterial cultures on solid media.

o The bacteriophage is mixed with bacteria and a melted agar to incubate and

allow viruses to be released and invade more bacteria, multiply and release

tons of viruses (which in turn invade more bacteria and release more viruses).

o Produces plaques or clearings on an agar where the bacteria has been

destroyed by the virus.

How are animal viruses cultured?

o We must infect live animals virally to watch for signs and symptoms. Animal

inoculation is used for diagnostic procedures to identify and isolate viruses for

clinical specimens. The animal is inoculated and then observed for signs of

disease or is killed and can be examined for the virus. Some human viruses

can not grow in animals and vice versa.



What is the difference between the lytic and lysogenic cycle of bacteriophage?

o Lytic cycle – ends with the lysis and death of the host cell

Attachment – phage attaches by tail fibers to host

Penetration – phage lysozymes opens cell wall; tail sheath contracts to

force tail core and DNA into cell

Biosynthesis – production of phage DNA and proteins

Maturation – assembly of phage particles

Release – phage lysozymes breaks cell wall to release virus and the

cell dies

o Lysogenic cycle – cell remains alive after the viral cycle is over

Phage attaches to host cell and injects DNA

Phage DNA circulartizes (turns into a circle) and enters lytic cycle or

lysogenic cycle

New phage DNA and proteins are synthesized and ensemble into

virions

cell lyses releases phage virions and infiltrates another bacteria

OR phage DNA integrates within the bacterial chromosome by

recombination becoming a prophage

Lysogenic bacterium reproduces normally and after many cell

divisions, the prophage may excise from the bacterial

chromosome by another recombination event, initiating a lytic

cycle

What are the steps involved in multiplication of animal viruses?

o Attachment – viruses attach to cell membrane

o Penetration – by endocytosis or fusion

o Uncoating – by viral or host enzymes

o Biosynthesis – production of nucleic acid and proteins

o Maturation – nucleic acid and capsid proteins assemble

o Release – by budding (enveloped viruses) or rupture

What are the similarities and differences between the multiplication of DNA and

RNA viruses?

o RNA multiplication is essentially the same as DNA multiplication except for

the following details

RNA viruses multiple in the cytoplasm

mRNA and viral RNA are produced differently

What is the difference between + and – strand RNA viruses (Review Fig. 13.17)?



o + strand or the sense strand transcribes for the + viral genome as the template

and transcribe – strands to produce additional + strands into capsid proteins as

the viral genome. These – strands make + strands, which are incorporated

into the capsid and then mature and release

o – strand or the antisense strand uses a + strand to serve as mRNA and begins

to synthesize proteins and will transcribe additional – strands for capsid

proteins

Define oncogene and transformation.

o Oncogene – a gene that can bring about malignant transformation to the

cellular genome

o Transformation – the switch from being a normal cell to a cancerous cell

through a process in which genes are transferred from one bacterium to

another as “naked” DNA is solution

How do viruses cause cancer? Give examples of oncogenic viruses.

o Approximately 10% of cancers are known to be virus induced

o After transformed by the virus to differentiate them from uninfected cells and

even the infected cells that do not make tumors. These viruses-infiltrated and

tumor creating cells have a TSTA antigen on the cell surface and contain an

antigen in their nucleus. These infected cells create more of the virus through

the lytic and lysogenic cycle and create more of the virus and more infection.

o Hepatitis B virus is a DNA virus that has been known as a causal role of liver

cancer. Virtually all the people in one human study that had liver cancer had

HBV infections some time in the past.

What is the difference between latent and persistent viral infections?

o Latent viral infections stem from pathogens that remain in the host for long

periods of time and DO NOT PRODUCE a disease and are not fatal

o Persistent viral infections DO PRODUCE a disease over a long period of time

and tend to be fatal.

Describe how a protein can be infectious.

o If an abnormal prion protein enters a cell, it changes a normal prion protein to

PrP, which now changes another normal PrP, resulting in an accumulation of

the abnormal PrP

What is a viroid?

o An infectious RNA strain about 300-400 nucleotides long with no protein coat

Chapter 14

Define pathology, etiology, normal microbiota, and transient microbiota.



o Pathology – the study of disease

o Etiology – the study of the cause of a disease

o Normal microbiota – permanently colonize the host and never cause diseases

o Transient microbiota – may be present for days, weeks or months and can also

be localized in regions

What factors affect the growth of normal microbiota?

o Nutrients, physical and chemical factors, defenses of the host and mechanical

factors.

What is microbial antagonism? List some examples.

o Microbial antagonism is a competition between microbes

o An example is C. difficile in the large intestines. C. difficile makes host

receptors unavailable and compete with other bacteriocins for available

nutrients (aka microbial antagonism)

What is the difference between commensalism, mutualism, and parasitism?

o Commensalism – one organism benefits and the other is unaffected

o Mutualism – both organisms benefit

o Paratism – one organism benefits at the expense of another

How do opportunistic pathogens cause disease?

o Opportunistic pathogens do not normally cause disease in a normal, healthy

person but may affect those in a different environment (like broken skin or

mucous membranes and by using these methods, they can cause disease).

E.g. – contracting pneumonia when AIDS is rampant (would not

normally get pneumonia unless in this immune compromised state)

What are Koch’s postulates and why were they created?

o Koch’s postulates give framework to study the etiology in infectious diseases

thorugh the following postulates

The same pathogen must be present in every case of the disease

The pathogen must be isolated from the diseased host and grown in

pure culture

The pathogen form the pure culture must cause the disease when it is

inoculated into a healthy, susceptible laboratory animal

The pathogen must be isolated from the inoculated animal and must be

shown to be the original organism

What are exceptions to Koch’s postulates?

o The microbes that have unique culture requirements or cannot grow on

artificial media whatsoever



o Microbes can also cause several disease conditions, making it difficult to

identify or have a consistent diseased result

What is the difference between a communicable and noncommunicable disease?

o Communicable diseases – a disease spreads from one host to another either

directly or indirectly

o Noncommunicable diseases – not spread from one host or person to another

Ex – tetanus from a nail

How are diseases categorized according to occurrence?

o Incidence – number of people who DEVELOP the disease in a period of time

o Prevalence – number of both OLD AND NEW cases of a disease in a

particular period of time

o Sporadic disease – occurs occasionally

o Endemic disease – consistently present in a population

o Epidemic disease – disease acquired by many hosts in a given area in a short

time – flu and AIDS

o Pandemic disease – an epidemic disease that occurs worldwide

o Herd immunity – immunity in most of a population (which tends to stem from

mass vaccination)

How are diseases categorized according to severity or duration?

o Acute disease – one that develops rapidly but only lasts a short time (the flu)

o Subacute disease – a disease that is intermediate between acute and chronic

o Chronic disease – develops more slowly, the body’s reactions are less severe

and can continue for long periods (and are considered much more deadly)

o Latent disease – disease with a period of no symptoms and the causative agent

is inactive

What are the stages of a disease?

o Incubation period – no signs and symptoms

o Prodromal period – mild signs or symptoms

o Period of illness – most severe signs and symptoms

o Period of decline – signs and symptoms

o Period of convalescence – signs and symptoms are declining and disappearing

What is a reservoir of infection? Give examples of the various types of reservoirs.

o A reservoir of infection is a continual source of infectious microbes to fuel the

infection constantly. They must be either located on the organism or on an

inanimate object to survive and multiply on a human, animal or nonliving

surface



o Human reservoir – people with s/sx of the disease

o Animal reservoir – zoonoses – infections on a wild or domestic animals and

are transported to humans either through direct contact, contaminated food,

water or furs and even from consuming infected animal products

o Nonliving reservoir – soil and water are the main infection reservoirs

What are the different methods of disease transmission?

o Contact

Direct – requires close association between infected and susceptible

host with no intermediate

Indirect – spread by formites and use intermediate to transmit a disease

(like a Kleenex)

Droplet – transmission via airborne droplets

They can’t travel far and through coughing or sneezing

o Vehicle transmission – transmission by an inanimate reservoir (food, water,

air, blood, IV, etc)

o Vectors

Mechanical – arthropod carries pathogen on feet (passive)

Biological – pathogen reproduces in the vector (active)

Ex-mosquito vomiting into the bloodstream

What is a nosocomial infection and how are they transmitted?

o Nosocomial infetions are acquired as a result of a hospital stay and affect 5-

15% of all hospital patients (20,000 die as a result)

o Result from several factors

Microbes in the hospital environment

Compromised/weakened status of the host (patient)

The chain of transmission in the hospital

What are the 3 types of epidemiologic investigations?

o Descriptive epidemiology – collection and analysis of data

Describes occurrence (retrospective)

o Analytical – comparison of a diseased group and a healthy group

Determines probable cause

Cohort study

o Experimental – controlled experiments using the scientific method

Define morbidity and mortality.

o Morbidity – incidence of a specific notifiable disease

o Mortality – deaths from notifiable diseases



Chapter 15

What are the principal portals of entry for a microorganism?

o Mucous membranes – mainly in GI and respiratory tracts

o Skin – largest membrane – enter through hair follicles and skin gland ducts

o Parenteral route – punctures, injections, bites and cuts

o Preferred portal of entry is through the respiratory tract by swallowing,

inhalation or ingested in the GI tract

Define ID50 and LD50.

o ID50 – infectious dose for 50% of the test population

o LD50 – lethal dose of a toxin for 50% of the test population and shows the

potency of a toxin

How do microorganisms adhere to a cell?

o Adhesins or ligands bind to the receptors on host cells and is a necessary step

of pathogenicity

Examples: glycocalyx, fimbriae and m proteins

o Can form biofilms

How do capsules, cell wall components, and enzymes contribute to the pathogenicity

of a microorganism?

o Capsules

Resist the host’s defense by impairing phagocytosis and can not be

destroyed

If the body forms antibodies to degrade the capsule, then the

microbe can by phagocytized

o Cell wall components

Contain chemical substances causing virulence

M protein – resists phagocytosis

Opa protein – inhibits T helper cells

Mycolic acid – waxy lipid that resists digestion

o Enzymes

Causes virulence of some bacteria

Coagulase – coagulates fibrinogen in the blood

Kinases – digest fibrin clots to isolate infections

Hyaluronidase – hydrolyzes hyaluronic acid, a type of polysaccharide

glue

Collagenase – hydrolyes collagen

IgA proteases – destroy IgA antibodies



What is the function of siderophores?

o Siderophores are bacterial iron-binding protein. They are released into the

medium, find iron and attach to it, bring it back to a siderophore receptor on

the bacterial surface and then the whole compound is brought into the cell.

These siderophores are used to survive.

Compare and contrast the mechanism and effects of exotoxins and endotoxins.

o Exotoxins – specific for a structure or function in the host cell

Transported by bacterial plasmids or phages

Produced in bacteria and are released into surrounding medium after

lysis

Proteins

o Endotoxins – part of the outer portion of the cell wall

Only on gram (-) bacteria

Outer peptidoglycan layer of the bacteria

Lipopolysaccharides

Released when the gram (-) bacteria die

Stimulate macrophages to release cytokines in very high

concentrations (toxic)

All endotoxins produce the same signs and symptoms, even if not the

the same degree

Can produce shock

What is the purpose of the LAL assay?

o LAL (limulus amoebocyte lysate) assay detects minute amounts of

endotoxins. Large amounts of proteins cause clotting and in the presence of

an endotoxin, will cause a gel-clot. The degree of clotting and reaction is

measure using a spectrophotometer.

What are the characteristics of A-B toxins, membrane-disrupting toxins, and

superantigens?

o A-B toxins - first toxins studied and A and B are both polypeptides

A is active

B is the binding component

o Membrane-disrupting toxins – causes lysis of the host cells and disrupts the

plasma membrane

Can destroy the plasma membrane through forming protein channels

or disrupt phospholipids

contributes to virulence by killing host cells (especially phagocytes)



o Superantigens – antigens that provoke a very intense immune response

Considered to be bacterial proteins

What are the cytopathic effects of viral infections?

o Can cause macromolecular synthesis within the host cell to stop

o The host cell’s lysozymes release their enzymes to destroy the intracellular

contents and cause host cell death

o Create inclusion bodies in the cytoplasm of infected cells

o Form a syncytium – a large multinucleate cell produced from viral infections

o Can cause host cell’s function with no visible changes in the infected cells

o Infected cells can produce interferon’s to protect uninfected cells around the

infected from viral infection

o Induce antigenic changes on the surface of the infected cells

o Can cause chromosomal changes in the host cell

o Can cause contact inhibition – normal cells cease growing in vitro when

coming close to another cell

What are the causes of symptoms in fungal, protozoan, helminthic, and algal

diseases?

o Fungal – toxins produce by the fungi are an indirect cause of disease because

the fungus itself is already growing on the host

o Protozoan – the presence of the protozoa and their waste products often

produces disease symptoms in the host

o Helminthic – their presence causes symptoms and produce disease in the host

cell

o Algal – produce neurotoxins to infect the host

Chapter 16

What is the difference between innate and adaptive immunity?

o Innate immunity is an immune response from birth and is not specific (VERY

FAST)

o Adaptive immunity shows a resistance to a specific pathogen and is memory

driven, therefore VERY slow

Define toll-like receptors.

o TLRs are transmembrane proteins of immune cells that recognize pathogens

and activate an immune response directed against those pathogens

What are the various physical and chemical factors that make up the first line of

defense?

o Intact skin



Keratin – protective protein in the skin

Sebum – prevent hairs from drying out and becoming brittle

Lysozymes – found in perspiration glands to break down gram (+) cell

walls

o Mucous membranes and their secretions

Mucus - a viscous glycoprotein that prevents the mucous membranes

from drying out

Salivia – dilute the number of microbes and wash them from surfaces

o Normal microbiota – multiple microbes that don’t cause disease to the body

that are located in the areas mentioned above

How do normal microbiota contribute to innate immunity?

o Competitive exclusion allows the normal microbiota to fight off pathogenic

microbes. The normal microbiota and invader microbes fight over the same

nutrients and surface area, so when the normal microbiota wins, it protects the

host from invaders in a sense.

What are the different cells types that can be found in the blood? What is the function

of each?

o Erythrocytes – red blood cells

Transport O2 and CO2

o Leukocytes – white blood cells

Granulocytes

Neutrophils – phagocytosis and are active in the initial stages

of infection

Basophils – release histamines, which are important in

inflammation and allergic reactions

Eosinophils – somewhat phagocytic and can leave the blood

and produce toxic proteins to destroy parasites and helminths

Agranulocytes

Monocytes – phagocytosis once they leave circulating blood

and turn into macrophages

Dendritic cells – derive from monocytes and look like dendrites and

destroy microbes with phagocytosis

Natural killer cells – a lymphocyte that destroys target cells

T cells – lymphocyte that has cell-mediated immunity

B cells – lymphocyte that protects the host by producing antibodies

Platelets – clots blood



What types of cells are considered phagocytes?

o Those that clear microbes or debris to counter infection

o Anything that is in the second line of defense

o Neutrophils, fixed macrophages and wandering macrophages do this

How does phagocytosis occur? (Review Figure 16.7)

o Chemotaxis and adherence of microbe to phagocyte

o Ingestion of microbe by phagocyte

o Formation of a phagosome

o Fusion of the phagosome with a lysosome to form a phagolysosome

o Digeston of ingested microbe by enzymes

o Formation of the residual body containing indigestible material

o Discharge of waste materials

How do microbes evade phagocytosis? Give examples

o If their capsule cannot be grasped

o Can be ingested by the phagocyte but not killed

o Intracellular pathogens secrete toxins to kill the phagocyte

What are the stages of inflammation?

o Initial damage to healthy tissue

o Vasodilation with increased permeability of blood vessels through

prostaglandins, histamines, kinins, leukotrienes and cytokines from the

damaged cells

o Phagocyte migration and phagocytosis of bacteria and cellular debris by

macrophages and neutrophils

o Repair of damaged tissue

Describe the process of phagocyte migration.

o As the blood flow decreases, phagocytes stick to the inner endothelium blood

vessels. This sticking process is called margination.

o Collected phagocytes squeeze between endothelial cells to reach the damaged

area.

o Phagocytes begin to destroy the invading microbes through phagocytosis

What are the causes and effects of fever?

o Gram negative endotoxins cause phagocytes to release interleukin. The

hypothalamus counters by releasing prostaglandins and they reset the

hypothalamus to be at a higher temperature

o The body also increases its rate of metabolism and shivers to raise

temperatures.



o The effects of fever are both positive and negative

Positive: increases transferrins, increases IL-1 activity and produces

interferon

Negative: causes tachycardia, acidosis, dehydration and a temperature

too high is fatal

How is complement activated? What is the consequence of complement activation?

o Activated by antigen-antibody reacton

o Proteins C3, B, D, P and a pathogen

o This system complements the immune system and helps destroy microbes

Is not adaptable and does not change over time (belongs to the innate

immune system)

o The complement protins cause a cascade to

Opsonization or immune adherence (an enhanced phagocytosis)

Cause cytolysis; a membrane attack complex

Attract phagocytes

Compare and contrast the various types of interferons.

o Alpha interferon’s – cause cells to produce antiviral proteins that inhibit viral

replication

o Beta interferon’s – same as alpha

o Gamma interferon’s – cause neutrophils and macrophages to phagocytize

bacteria



Final Exam Study Guide Mary-Catherine Ciuba

Chapter 17

What is meant by humoral and cellular immunity?

o Humoral immunity is the protection brought about by antibodies

o Cellular immunity is

What types of cells are involved in the cell-mediated immune response?

o Thymus – a lymphoid organ in the upper chest

Formed after puberty

o Bursa of Fabricius – a lymph node type structure

Define antigen and epitope.

o Antigens – proteins or large polysaccharides that are often components of

invading microbes, such as capsules, cell walls, flagella, fimbriae and toxins

of bacteria

o Epitopes – antigenic determinants with specific regions on antigens

What are the structural components of antibodies?

o Antigen binding site

o Fc (stem) region

o Hinge reaction area

What are the characteristics of the different antibody classes?

o IgG – monomer in the blood, lymph and intestines that maternally protects the

fetus passively with its transmission through the placenta

o IgM – biggest antibody, stays in the blood and is the first Ab produced in

response to infection

o IgA – most common antibody in the body, found in the mucous membranes

and prevents attachment of microbial pathogens

o IgD – monomers that resemble IgG in the blood, lymph and B cells that have

no known function

o IgE – monomer that interacts with lymphocytes and participates in allergic

reactions to release histamines and chemical mediators

Describe the process of clonal selection.

o Antibodies can bind to antigens

Agglutination – reduces the number of infectious units to be dealt with

Activation of complement – causes inflammation and cell lysis

Opsonization – coating antigen with antibody enhances phagocytosis

Antibody-dependent cell-mediated cytotoxicity – antibodies attached

to target cells that cause destruction by macrophages, eosinophils and

NK cells



Neutralization – blocks adhesion of bacteria and viruses to mucosa

What are the 5 processes that occur as a result of the antigen-antibody complex?

(Fig.17.7)

o Stem cells differentiate into mature B cells, each bearing surface

immunoglobulin’s against a specific antigen

o B cells can recognize an almost infinite number of anitgens, thought a

particular cell recognizes only one type of antigen

o B cell III complexes with its specific antigen and proliferates

o Some B cells proliferate into long-lived memory cells, which can be

stimulated to become an antibody producing plasma cell

o Other B cells proliferate and create antibody-producing plasma cells

o Plasma cells secrete antibodies into circulation

What is the function of T helper cells (TH1 and TH2), T cytotoxic cells, T regulatory

cells, and NK cells?

o Th1 – activates cells related to cell-mediated immunity, macrophages and Abs

o Th2 – activate eosinophils and B cells to produce IgE

o Tc – target cells are self carrying endogenous antigens

Become CTLs

o Treg – combat autoimmunity by suppressing T cells that escape deletion in the

thymus without the necessary smarts to avoid reacting with the body’s self

o NK cells – attack viral cells, tumors and parasites and are NOT

immunologically specific

What are antigen-presenting cells? What are the types of antigen-presenting cells?

o B cells – phagocytizes microbes

o Dendritic cells – look like dendrites

o Activated macrophages – uses T cells to activate

What is meant by immunological memory?

o The anti-body mediated immune response of the host intensifies after a second

exposure to tan antigen, known as the secondary and memory response.

o Still in tact years or decades later

What are the 4 types of adaptive immunity?

o Naturally acquired active immunity – exposure, illness and recovery

o Naturally acquired passive immunity – mother to infant illness

o Artificially acquired active immunity – vaccination protection

o Artificially acquired passive immunity – injection of antibodies into the body

Chapter 18



Why is vaccination important for viral diseases?

o Vaccines prevent bacterial and viral diseases from infecting someone and

ultimately killing them. A vaccine gives someone a small dose of the virus

and that person recovers and has an extreme secondary immune response

when it comes into contact with that virus again.

What are the different types of vaccines and their characteristics?

o Attenuated whole-agent vaccines – living but weakened microbes

o Inactivated whole-agent vaccines – uses killed microbes

o Toxoids – inactivated toxins used in a vaccine

o Subunit vaccines – antigenic fragments that stimulate an immune response

o Nucleic acid vaccines – DNA codes a protein antigen and stimulates humoral

and cellular immunity to fight it off

How are vaccines developed?

o First you must culture the pathogen you want to inoculate the host with. Most

vaccines use diseases from humans so that the transmission is more pure.

o The chick embryo or another intermediate is used to grow the viruses (but

recombinant/DNA vaccines don’t need one)

o Tested and used for injection

What is an adjuvant?

o Substances in vaccines that greatly increase the effectiveness of the antigens

What are monoclonal antibodies and how are they useful?

o Monoclonal antibodies are antibody molecules created by a single hybridoma

clone

They are uniform, produced in high quantities and extremely specific

Describe the purpose and mechanism of the following reactions/tests: Precipitation

reactions, Direct agglutination tests, Indirect agglutination tests, Hemagglutination,

Neutralization reactions, Complement fixation, FA techniques, ELISA, and Western

Blot.

o Preciptation reactions – reaction of soluble antigens with IgG or IgM to form

large molecules called lattices

Antigens and antibodies rapidly form small complexes and bond

together in solution to form a lattice precipitate

o Direct agglutination tests – detects antibodies against relatively large cellular

antigens (RBCs, bacteria and fungi)

Do in plastic titer plates to test the concentration of a serum antibody



Most dilute the antibodies so you don’t have enough to kill all

the antigens

o Indirect agglutination tests – antibody reacts with the soluble antigen adhering

to the particles

Tests against antigens for which they are specific

o Hemagglutination – clumping of red blood cells

Some viruses can agglutinate RBCs without an antigen-antibody

complex

o Neutralization reactions – harmful effects from a bacterial exotoxin / virus

blocked by antibodies

o Complement fixation – used to detect very small amounts of antibody

o FA techniques – identifies microbes in the clinical spectrums and detects

specific anitobides in a serum

Uses a stain and fluorescence microscopy

o ELISA – direct identifies antigens and indirect detects antibodies

Shallow wells where the organisms congregate

Can do direct and indirect simultaneously

o Western blot – identifies a specific protein in a mixture

Chapter 19

What is an allergen?

o What are the characteristics of Type I, II, III, and IV reactions? What types of

immune responses are induced in each case? Give examples of each type of reaction.

o What is an autoimmune disease? What are some examples?

o Describe the uses of stem cells?

o Differentiate between autograft, isograft, allograft, and xenograft.

o What is graft-versus-host disease?

o How is transplant rejection prevented?

o How do cancers evade the immune system?

o



Define immunodeficiency.

o How does HIV evade the immune system?

o What are the stages of HIV infection?

o How is HIV diagnosed?

o How is HIV treated?

o Chapter 20

How are Paul Ehrlich and Alexander Fleming responsible for the birth of modern

chemotherapy?

o What are the 5 modes of action of antimicrobial drugs?

o Describe how the following antimicrobial drugs kill or inhibit the growth of bacteria:

penicillins, chloramphenicol, tetracyclines, quinolone, and sulfonamides.

o What are the mechanisms of action of antifungal drugs?

o What are the mechanisms of action of antiprotozoan and antihelminthic drugs?

o What are the mechanisms of action of antiviral drugs?

o Describe the disk-diffusion method and MIC.

o What are 3 new approaches for chemotherapeutic agents?

o



Departmental Final Exam Mary-Catherine Ciuba

Identify the contributions to microbiology made by the following scientists: Needham,

Spallanzani, Virchow, Pasteur, Lister, Koch, Jenner, Ehrlich, and Fleming.

What is the order of the subdivisions that make up the taxonomic hierarchy? Which subdivision

is least/most specific? (Figure 10.5)

How is the total magnification of a compound light microscope calculated?

What are the components of the cell walls of gram-negative and gram-positive bacteria?

Where does ATP production occur in eukaryotic and prokaryotic cells?

What is meant by phototroph, chemotroph, autotroph, and heterotroph?

What are the 5 groups that classify microorganisms based on their temperature requirements?

Describe how microorganisms are classified based on their different oxygen requirements.

How does an autoclave control microbial growth?

List the various types of microorganisms in terms of resistance to chemical biocides. (Figure

7.11)

What are 3 methods of genetic recombination in bacteria?

What is the flow of genetic information in the cell?

What is meant by semiconservative replication?

What are the characteristics of fungi?What are some common diseases caused by fungal

infections?

By what characteristics are fungi, lichens, algae, and protozoa classified?

Describe the physical and chemical structure of both an enveloped and nonenveloped virus.



What are the characteristics of exotoxins?

What are the various stages of a disease?

Define and identify the causes of nosocomial infections.

What leukocytes are capable of phagocytosis?What are the characteristics of these

phagocytes?

What cells are involved in the adaptive immune response?What are their functions?

What are the characteristics of Mycoplasmas?

Describe the mechanism of action of each of the following antibiotics:tetracycline, rifampin,

sulfonamide, penicillin, and polymyxin B.

*What diseases are caused by protozoa? (Chapter 12, Table 12.5)

*Describe examples of parasitic infections in which humans serve as definitive hosts. (Chapter

12)

*What are the characteristics of viral hepatitis? (Chapter 25, pg. 724)

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