BIOL 2333-A Microbiology
Describe some of the destructive and beneficial actions of microbes.
Destructive: Few are disease-causing (ex: fever, diarrhea) and spoils food.
Describe some of the destructive and beneficial actions of microbes.
Beneficial : produce fermented foods (cheese, bread, vinegar), produces industrial chemicals (ethanol and acetone), decompose organic wastes, are producers in the ecosystem by photosynthesis, produce products used in manufacturing and treatment (insulin)
Distinguish a genus from a specific epithet.
Established by Carolus Linnaeus (1735)
a genus : Capitalized the first letter
a specific epithet (species ): species/specific epithet all lowercase
Need to be italicized or underlined
The scientific name of an organism includes its
genus and species .
Ex: Staphylococcus aureus OR Homo sapiens
In the name Staphylococcus aureus, aureus is the
A)
kingdom.
B) genus.
C) domain name.
D) specific
name.
E) family name
D) specific name.
What is a Refraction index?
Is the loss of light rays after we passed
them through the stained specimen. To avoid we add immersion oil
has the same reflation index the glass, the light rays do not
refract when passing through.
List the three domains
Bacteria
Archaea
Eukarya
Differentiate the major characteristics of Bacteria
Prokaryotic, unicellular organism
Lack a membrane-bounded nucleus
Reproduce asexually
Heterotrophic by absorption
Differentiate the major characteristics of Archaea
Prokaryotic, unicellular organisms
Lack a membrane-bounded nucleus
Reproduce asexually
many are autotrophic by chemosynthesis; some are heterotrophic by absorption
Differentiate the major characteristics of Eukarya
Eukaryotic, unicellular to multicellular organisms
Membrane-bounded nucleus
Sexual reproduction
Phenotypes and nutrition are diverse
Which groups of microbes are prokaryotes? Which are eukaryotes? How can you distinguish between them?
Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-enclosed organelles.
Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus (that holds genetic material) as well as membrane-bound organelles.
Which of the following is not a characteristic of
prokaryotes?
A) DNA
B) Cell membrane
C) Cell wall
D) Endoplasmic reticulum
D) Endoplasmic reticulum
Eukaryotic cells are more complex than prokaryotic cells. Which
would you not find in a prokaryotic cell?
A) Cell wall
B) Plasma membrane
C) Nucleus
D) Ribosomes
C) Nucleus
______using a simple microscope was the first to observe microorganisms
Anton van Leeuwenhoek
The scientist usually considered the first to see
microorganisms, which he called "animalcules",
was
a)Redi
b) Anton von Leeuwenhoek
c)Pasteur
d) Tyndall
b) Anton von Leeuwenhoek
Which of the following individuals
is
considered to be the
“Father of
Microbiology?”
a. Anton von Leeuwenhoek
b. John Tyndall
c.
Louis Pasteur
d. Robert Koch
e. Rudolf Virchow
a. Anton von Leeuwenhoek
Koch provided the experimental steps, “Koch’s postulates”, to prove that a specific microbe causes a specific disease, what are those steps?
1.The same pathogen must be present in every case of the disease
2.The pathogen must be isolated from the diseases host and
grown in pure culture
3.The pathogen from the pure culture must
cause the disease when it is inoculated into a healthy, susceptible
lab animal
4.The pathogen must be isolated from the inoculated
animal and must be shown to be the original animal
Which of the following is NOT part of Koch's postulates?
D) The microorganism must secrete a toxin in culture.
The formal steps (postulates) by which a microbiologist can
demonstrate that a particular disease is caused by a particular
microbe were first laid down by
a. Louis Pasteur
b.
Robert Koch
c. Alexander Fleming
d. Edward Jenner
e. Ignaz Semmelweis
b. Robert Koch
Spontaneous generation:
the hypothesis that living organisms arise from nonliving matter; a “vital force” forms life.
Ex: three jars were covered with net and there were no maggots
Three open jars maggots appears
The idea of spontaneous generation postulated that
a.
organisms could evolve into the next generation of organisms.
b. organisms could spontaneously combust.
c. organisms could
spontaneously arise from other living
organisms.
d.
living organisms could arise from nonliving material.
d. living organisms could arise from nonliving material.
Biogenesis:
The hypothesis that the living organisms arise from preexisting life
Biogenesis refers to the
A) spontaneous generation of
organisms from nonliving matter.
B) development of life forms
from preexisting life forms.
C) development of aseptic
technique.
D) germ theory of disease
Ex: When the flask is tilted the microorganism are able to enter the broth and they grew in the broth this showed the microorganism did not appear spontaneously
C) development of aseptic technique
Pasteurization:
heat (below boiling) for short period of time to kill pathogens and reduce bacteria count, does not kill all bacteria- some survive
Pasteurization involves the:.
A) exposure of food to high temperatures for short periods to destroy harmful microorganisms.
B) exposure of food to heat to inactivate enzymes that cause undesirable effects in foods during storage.
C) fortification of foods with vitamins A and D.
D) use of irradiation to destroy certain pathogens in foods.
A) exposure of food to high temperatures for short periods to destroy harmful microorganisms.
Ionic bond=
when it gives up an electron to make the valence electrons stable
Covalent bond=
is when you share electrons to make the valence electrons complete/ balance
Polar covalent bond=
atoms are shared unequally
Non polar covalent bond=
Atoms are shared equally
Atoms that have the same atomic number (are of the same element) but different atomic weights are called______?
isotopes .
Isotopes of the same element must have the same
number of
A) neutrons
B) protons
C) electrons
D) both A
and B
E )both A and C
B) protons
Isotopes of the same element must have different
numbers of
A) neutrons
B) protons
C) electrons
D) both A
and B
E)both A and C
A) neutrons
A hydrogen bond exists when a hydrogen atom ______ to one oxygen or nitrogen atom is attracted to another ______.
covalently bonded,
oxygen or nitrogen atom.
Which statement about hydrogen bonding is
true?
A) Hydrogen bond is formed by sharing electrons between
atoms.
B) Hydrogen bond also requires formation of
ions.
C)
Hydrogen bond is a weak force between atoms in a molecule but is of
enormous importance in physiology.
D) Hydrogen bond is nothing
but a different form of hydrogen ion .
C) Hydrogen bond is a weak force between atoms in a molecule but is of enormous importance in physiology.
Example of compound having hydrogen bonding
is
A) Chlorine gas
B) neon
C)sodium chloride
D) water
C)sodium chloride
Which of the following is the type of
bond
between molecules of water in a beaker of water?
A)Ionic Bond
B)Covalent Bon
C) Hydrogen Bond
D) Disulfide Bond
E) Electrostatic interactions
C) Hydrogen Bond
Endergonic reactions require more ____ than they_____?
energy, release;
Exergonic reactions release more or less energy.
more
Anabolism =
to build up a new molecule (creating polymers from monomers by dehydration synthesis)
Catabolism =
breaking down molecules in cell (adding H2O to break down the bond, now you have hydrolysis reaction)
Because water is a_______ , it is an excellent______ .
polar molecule,solvent
The bond joining glucose and fructose together to form sucrose is
A) A glycosidic linkage
B) dehydration synthesis
C) Dipole-dipole bonds
D) Phosphodiester bond
E) Ester linkage
A) A glycosidic linkage
What bond links the fatty acid tail to the
glycerol in a lipid
A) Glycosidic
B) Peptide
C) Ester
D) Phosphodiester
E) Van der Waals
C) Ester
Dehydration synthesis reaction :
removal of water to form a bond
Hydrolysis
adds a water molecule, breaking a bond
Both glycosidic and peptide linkages result from_____
dehydration synthesis
What happens during a hydrolysis reaction?
A) A protein coils into its secondary structure
B) The bond between two subunits of a macromolecule is broken
C) Saturated fats become unsaturated
D) A bond is formed between two subunits of a macromolecule
E) Water breaks ionic bonds
B) The bond between two subunits of a macromolecule is broken
Monomers usually bond together by _______ that form water and a polymer.
dehydration synthesis
Polymers may be broken down by ______ a reaction involving the splitting of water molecules.
hydrolysis
Dehydration reaction is removing______________?
Water + Glucose + Fructose
Hydrolysis is by adding ______?
Sucrose + water
Proteins have four levels of structure:
primary (sequence of amino acids)
secondary (helices or pleats)
tertiary (overall three-dimensional structure of a polypeptide)
Quaternary (two or more polypeptide chains).
primary (sequence of amino acids)
secondary (helices or pleats)
tertiary (overall three-dimensional structure of a polypeptide)
Quaternary (two or more polypeptide chains).
What is the total magnification of a compound light microscope with objective lens magnification of 40X and ocular lens of 10x
400X
GRAM NEGATIVE
GRAM POSITIVE
The DNA found in most bacterial cells___.
is circular in structure.
Gram negative differ from Gram positive in
having
A) Thick
wall
B) Absence
of wall lipids
C) Complex
wall
D) Simple wall
C) Complex wall
Lipopolysaccharide is found in cell wall of
A) Gram positive
bacteria
B) Gram negative
bacteria
C) Both Gram,
positive and Gram Negative
D) Algla
B) Gram negative bacteria
coccus
bacillus
Spirillum
How would you be able to identify streptococci through a microscope?
It would look like a chain of spheres under the microscope
How would you expect the effect of drugs to differ between gram-positive and gram-negative organisms?
Answer: Gram positive have a strong PG so the drugs won't destruct it ex: penicillin
Gram negative- have a thin wall so it is susceptible to destruction of chemicals ex:tetracycline
Flagella=
Long appendages. Made of chains of flagellin, attached to a protein hook.
Anchored to the wall and membrane by the basal body.
axial filaments=
In bacteria called spirochetes. Its anchored at one end of a cell, and spirals around. When it rotates causing the cell to move
Fimbriae=
Short appendages that allow attachment ( velcro) not movement
Can be at cell poles/ all over
Pili
Facilitate transfer from DNA from 1 cell to another
gliding,
and twitching.
Eukaryotic=
cells contain organelles which include mitochondria,chloroplast the endoplasmic reticulum, the Golgi apparatus, and lysosomes
Mitochondria=
powerhouse of the cell.
Smooth ER=
synthesize phospholipids,fats, and steroids
Release glucose in blood stream, detoxify drug-alcohol
Rough ER=
process plasma membrane, process ribosomes
Peroxisomes=
amino acids and fatty acids are oxidized and protects the cell from toxic effect of H202
Lysosomes=
break molecules, digest bacteria that enter the cell, and phagocytosis WBC contain lysosomes
Golgi apparatus=
Membrane formation and secretion. It is the package house of the cell where macromolecules like proteins and lipids as they are synthesized within the cell.
ALCOHOL
AMINO
CARBONYL
CARBOXYL
METHYL
PHOSPHATE
SULHYDYL
Hydroxy
What are the three domains of life?
-Bacteria(cyanobacteria, heterotrophic bacteria)
-Archaea(Halophiles and Thermophiles)
-Eukarya
Which groups of microbes are prokaryotes?
Answer: Bacteria and archaea
Which component is not found in the cytoplasm of the majority of
prokaryotes?
A) Capsule
B) Ribosomes
C)
Granules
D) DNA
E) Nucleoli
A) Capsule
Which are eukaryotes? How can you distinguish between them?
The main difference between the two is the presence of a “true” nucleus: eukaryotes have one, while prokaryotes do not.
Prokaryotes
Their cell wall has no peptidoglycan layer.
They have no histone
Their cell wall have a peptidoglycan layer
Reproduce usually by binary fusion
Eukaryotes
Cell wall has peptidoglycan layer
Dna has histone
They have chemically simple cell walls.
They reproduce by mitosis
Summarize in your own words the germ theory of disease
The idea that tiny organisms called microbes cause infectious
diseases that are easily passed among humans.
Which of the following is NOT part of Koch's
postulates?
A)
the microorganism is never found in healthy animals.
B) the microorganisms is
always found in diseased animals.
C) the microorganism must cause disease
in healthy animals.
D) the
microorganism must secrete a toxin in culture.
D) the microorganism must secrete a toxin in culture.
Define normal microbiota and their types
Normal microbiota or normal flora
refers to the organism that colonizes the body’s surfaces without normally causing disease.
Resident microbiota
permanently colonizes the host and is established during the first months of life.
Transient microbiota
May be present for day, weeks, or month
Define resistance=
resistance
The ability to ward off diseases through innate and adaptive immunity
Define biofilm =
Microbes attach to solid surfaces and grow into masses such as rocks, pipes, teeth and medical implants
Why are biofilms important?
Important in oil spills and purifying water.
How would you tell it was a virus?
If they contain a protein coat
Have a nucleic acid genome
Have a capsid
Obligatory intracellular parasites ( need a host cell to replicate)
The Virus is smaller than bacteria
True or False
Viruses have a cellular organization.
A)True
B)False
False(Viruses do not have a cellular organization and are therefore not classified with cellular organisms)
Viruses are classified by ____________.
A) viral size and
shape
B) type of
nucleic acid, including to whether the nucleic acid is single- or
double-stranded
C)
presence or absence of an outer envelope
D) all of the above
E) none of the
above since viruses are not living organisms and therefore cannot
be classified
D) all of the above
Which order below reflects the correct
procedure for Gram staining?
A. alcohol/acetone-crystal
violet-safranin-iodine
B. crystal
violet-alcohol/acetone-iodine-safranin
C. crystal
violet-iodine-alcohol/acetone-safranin
D. iodine-safranin-crystal
violet-alcohol/acetone
E.
alcohol/acetone-safranin-crystal violet-iodine
C. crystal violet-iodine-alcohol/acetone-safranin
Describe the appearance of gram-positive and gram-negative cells after each step.
1) First step use the first stain crystal violet (stains everything purple)
2) Than add the mordant (grams iodine) to help the chemical reaction along
3)Than wash with alcohol to decolorize anything that isn't chemically bonding
4)Than use the last stain: safranin (counterstaining)
The gram POS+ bacteria retain the purple stain after
the decolorization step
Gram NEG- bacteria do not and thus appear pink from the counterstain.
Why is the Gram stain so useful?
Being able to identify the Gram stain also means that in some cases, a clinician can get the patient started on antibiotic treatment even before the actual organism(s) is/are identified.
How would you expect the effect of these drugs to differ between gram-positive and gram-negative organisms?
Drugs directed towards bacteria i.e Gram - because of the peptidoglycan layer (second outer membrane has lipopolysacaride layer which allows it to be resistant to antibiotics).
Gram + have techoic acid, this allows charges to cross into the cell.
How do bacteria move?
Some bacteria have a single, tail-like flagellum or a small cluster of flagella, which rotate in coordinated fashion, much like the propeller on a boat engine, to push the organism forward. The hook: Many bacteria also use appendages called pili to move along a surface.
What is a spore?
A resting structure formed inside some bacteria. They can stay latent under their fixed conditions and activate when their nuclear components are activated.
What is an enzyme?
A substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction. AN ENZYME IS A PROTEIN, BUT NOT ALL PROTEINS ARE ENZYME
Describe the mechanism of enzymatic action.
Step 1 of mechanisms of enzymatic action surface of the substrate contacts a specific region on the surface of the enzyme called the active site
step 2 of mechanisms of enzymatic action a temporary enzyme-substrate complex forms lock and key
step 3 of mechanisms of enzymatic action substrate is transformed to products
step 4 of mechanisms of enzymatic action enzyme and products separate
step 5 of mechanisms of enzymatic action unchanged enzyme can react with other substrate
Enzymes are capable of recognizing and reacting with a special chemical substance called
A) activator
B) substrate
C) co-factor
D) co-enzyme
B) substrate
Kind of molecules at which enzymes act are classified as
D. substrates
The microbial process of converting sugars to alcohol is known as
A) alcoholism.
B) fermentation.
C)
pasteurization.
D) lyophilization.
E) tyndallization.
B) fermentation.
The first step for directly linking a microbe to a specific disease
according to Koch's postulates is to
A) inject a sample
of blood or other body fluid from a diseased animal into a healthy
animal.
B) isolate microbes from the blood of healthy animals.
C) obtain a sample of blood or other body fluid from a diseased
animal.
D) culture the blood or other body fluid from a
diseased animal using nutrient medium.
E) compare the blood of
a sick animal to blood obtained from a healthy animal.
C) obtain a sample of blood or other body fluid from a diseased animal.
In which of the following situations would Koch's postulates be
utilized?
A) determination of the cause of a patient's
illness in a hospital microbiology lab
B) development of a new
antibiotic in a pharmaceutical lab
C) whenever the scientific
method is used to investigate a microbiological problem
D)
formulation of a vaccine against a new pathogen in a genetic
engineering lab
E) determination of the cause of cancer in a patient
A) determination of the cause of a patient's illness in a hospital microbiology lab
Robert Koch identified the cause of
A) diphtheria.
B) AIDS.
C) anthrax.
D) tuberculosis.
E) smallpox.
C) anthrax
Antibiotics are produced by
A) bacteria.
B)
viruses.
C) protozoa.
D) fungi.
E) bacteria and fungi.
E) bacteria and fungi.
Why is enzyme specificity important?
Because the unique arrangement of each enzyme allows it to find the correct substrate from all the diverse molecules in a cell .
List the factors that influence enzymatic activity
Several factors affect the rate at which enzymatic reactions proceed - temperature, pH, enzyme concentration, substrate concentration, and the presence of any inhibitors or activators.
What happens to an enzyme below/above its optimal temperature?
The graph shows that as temperature is increased, the reaction rate of an enzyme increases. However, the graph shows that there is an optimum temperature where the reaction proceeds at its maximum. Above that optimal temperature, the reaction rate decreases.
Explain how the type of microbe affects the control of microbial growth.
The presence or absence of endospores has an obvious effect on microbial control.
Why are gram-negative bacteria more resistant to chemical biocides than gram-positive bacteria?
biocides tend to be more effective against gram-positive bacteria- external lipopolysaccharide layer of gram-negative bacteria, makes them resistant;
mycobacteria have a cell wall that is waxy, lipid-rich. viruses resistance depends on the presence or absence of an envelope.
How is microbial growth in canned foods prevented?
Drying is often used to preserve foods (e.g. fruits, grains, etc.). Methods involve removal of water from commercial sterilization: product by heat, evaporation, freeze-drying, and addition of salt or sugar.
Define normal and transient microbiota and their role in our health
Normal microbiota permanently colonize the host
Transient microbiota may be present for days, weeks, or months
What are opportunistic microorganisms?
Opportunistic microorganism: A bacterium, virus, protozoan or fungus that takes advantage of certain opportunities to cause disease. Those opportunities are called opportunistic conditions.They take advantage of a weak immune system.
How are nosocomial infections primarily transmitted?
NOSOCOMIAL INFECTIONS ARE USUALLY ACQUIRED IN HOSPITALS . THEY AFFECT IMMUNO COMPROMISED PATIENTS. I.E FROM CATHETER, OR ON ANTIBIOTIC TREATMENT.
A hospital acquired infection is
A)familial.
B)nosocomial.
C)genial.
D)viral.
E)potential.
B)nosocomial.
Explain how nosocomial infections can be prevented?
Using aseptic techniques, handling contaminated materials carefully, insisting on frequent hand washing, educate on infection control basics, and use isolation rooms.
The most common of all nosocomial infections are found
in the
A.
blood
B.
reproductive tract
C. urinary
tract
D. respiratory tract
C. urinary tract
What are true pathogens?
Cause disease in healthy person with normal immune defenses .
What factors contribute to an organism’s pathogenicity?
Portal of entry:Mucous membranes -respiratory system, GI tract, and skin
Penetration or Evasion of Host Defenses: Capsules, cell wall components, enzymes, antigenic variation
Damage to Host Cell:siderophores, direct damage, toxins (endotoxins and exotoxins), lysogenic conversion
Portal of exit: same as the portal of entry for a microbe
Identify the principal portals of entry and describe how microorganisms gain access through each
Portal of entry:Mucous Membrane most common route for pathogens
Respiratory tract, gastrointestinal tract , urinary/genital tract, conjunctiva
Identify the principal portals of entry and describe how microorganisms gain access through each
Skin (keratinized cutaneous membrane)
some pathogens infect hair follicles and sweat glands
few can colonize surface
unless broken, skin is usually an impermeable barrier to microbes
Identify the principal portals of entry and describe how microorganisms gain access through each
Parenteral route
penetrate skin: punctures, injections,
bites, cuts, surgery, etc.
deposit organisms directly into deeper tissues
Explain how microbes adhere to host cells?
Adherence specifically"
Tissue tropism: particular bacteria are known to have an apparent preference for certain tissues over others
e.g., S. mutans is abundant in dental plaque but does not occur on epithelial surfaces of the tongue; S. salivarius is in high numbers to epithelial cells of the tongue but is absent in dental plaque
Species specificity: certain pathogenic bacteria infect only certain species of animals
e.g., N. gonorrhoeae,
Genetic specificity within a species: certain strains or races within a species are genetically immune to a pathogen
e.g. (malaria)
Explain how capsules and cell wall components contribute to pathogenicity
Capsule- prevent phagocytosis (examples: Streptococcus pneumoniae and Haemophilus influenzae)
Cell wall components - M protein ( resist phagocytosis ex: Streptococcus pyogenes), Opa Protein ( inhibit T helper cells, promote attachment and uptake of host cell), Mycolic Acid (resist digestion ex:Mycobacterium tuberculosis)
Contrast the nature and effects of exotoxins and endotoxins
Exotoxin: Gram +, By-products of growing cell, Protein, No fever, yes neutralize antitoxins, LD50 small
Endotoxin: Gram -, outer membrane, Lipids, glycolipids, yes fever, not neutralized by antitoxins, LD50 large
Steps of A-B Exotoxins
1.Bacteria produces and releases exotoxin
2.B binding component of exotoxin attaches to host cell receptor
3.A-B exotoxins enters host cells by endocytosis
4.A-B exotoxin enclosed in pinched- off portion of plasma membrane during pinocytosis
5.A-B components of exotoxins separate. A component alters cell function by inhibiting proteins synthesis. The B component is released in the host cell
Describe the role of the skin and mucous membranes in innate immunity
First Line of Defense: Skin ( dermis & epidermis) Epidermis is tightly compacted top layer contains dead cells called keratin protective protein
Mucous Membrane- thick and moist epithelium
Describe the role of normal microbiota in innate immunity (16-5)
Normal microbiota complete with pathogen or alter the environment
More susceptible to infection (presence of normal flora continually challenges the immune system, keeping it active
Normal microbiota complete with pathogen or alter the environment
More susceptible to infection (presence of normal flora continually challenges the immune system, keeping it active
Distinguish microbial antagonism from commensalism
Microbial Antagonism: Normal flora inhibits overgrowth of harmful microbes.Mechanism includes competition for nutrients and affecting environmental factors such as ph, toxic substances and oxygen availability
Commensalism: one organism benefits, the other is not affected
(Many microbes live off secretions and dead cells and do not benefit or harm host cell)
Describe the roles of white blood cells in immunity
Answer: Increase during infection
When activated:
most leukocytes will produce cytokines
intercellular signaling
molecules/hormones that function to
trigger, enhance, and coordinate various defense mechanisms
Define phagocyte and phagocytosis
Phagocyte=From Greek, meaning eat, Cyte: From Greek, meaning
cell
Phagocytosis=Ingestion of microbes
or particles by a cell,
Phagocyte is an organism. I.e macrophage, basophils that ingest pathogen.
Phagocytosis is the process of ingesting an antigen by a macrophage or other phagocytic cells.
Explain the process of phagocytosis
Step 1
Chemotaxis and adherence of
microbe to phagocyte
Step 2
Ingestion of microbe to phagocyte
Step
3
Formation of phagosome
Step 4
Fusion
of the phagosome with a lysosome to form a
phagolysosome
Step 5
Digestion of ingested microbe
by enzymes
Step 6
Formation of residual body
containing indigestible materials
Step
7
Discharge of waste materials
What purposes does inflammation serve?
1) Destroy injurious agent and remove byproducts of injury
2) Limit spread of injury
3) Repair damaged tissue
What causes the redness, swelling, and pain associated with inflammation?
Redness-= Because of vasodilation
Swelling=increase in permeability permits fluid to move from blood
to tissue spaces
Pain associated=can be
because of nerve damage, irritation by toxin or the pressure of edema
Describe the cause and effects of fever?
cause: infection from bacteria and their toxins, or viruses. Gram
negative endotoxin cause phagocyte to release interleukin-1
effects: body increases rate of metabolism
and shivering which raises temperature vasodilation and sweating:
body temperature falls (crisis)
Prostaglandins released by the hypothalamus trigger the fever! Lowering the body tempature.
What is the purpose of complement and interferons?
Complement system:activation aids in destructions of microbes
The antibodies attack the cell which activated the complements to lysis the cell.
Interferons:signals proteins,triggers neighboring cells to produce antiviral proteins
Steps of the Antiviral actions of interferon
1.Viral RNA from an infecting virus enter the cell
2.The infecting virus replicates into new viruses
The infecting virus also induced the host cell to produce interferon mRNA which is translated into alpha and beta
4.Interferons releases by virus infected host cell bind to plasma membrane or nuclear membrane receptors on uninfected neighboring host cells, inducing them to synthesize antiviral proteins. These include oligoadenylate synthetase and protein kinase.
5.New viruses released by infected host cell infect neighboring cells.
6.AVPś degrade viral mRNA and inhibits proteins synthesis and thus interfere with viral infection
Explain the function of antibodies, and describe their structural and chemical characteristics
Special proteins produced by plasma cell ( B cells) recognize and bind to a specific epitope of an antigen via its antigen binding sites
Recognize and bind to specific shape. They have great specificity and each have 2 antigen binding sites
IgA
is an antibody that plays a crucial role in the immune function of mucous membranes
IgD
is an antibody isotype that makes up about 1% of proteins in the plasma membranes of immature B-lymphocytes
IgE
is a type of antibody (or immunoglobulin (Ig) "isotype") that has only been found in mammals. IgE is synthesised by plasma cells.
IgG
IgG,a monomer, is the predominant Ig class present in human serum
IgM
is one of several forms of antibody that are produced by vertebrates.
Agglutination:
reduces number of infectious units to be dealt with
Opsonization:
coating antigens with antibodies enhances phagocytosis
Neutralization:
Blocks adhesion of bacteria and viruse to mucosa and blocks attack of toxins
Antibody-
dependent cell cell mediated cytotoxins- antibodies attached to target cell causes destruction by macrophages,eosinophils,and NK cells
Activation of complement
Causes of inflammations and cell lysis
Why is the lymphatic system so valuable for the working of the immune system?
The Lymphatic system is the transport method of most pathogens. Bacteria or Viruses will travel to the lymph nodes where the CD4 and CD8 cells are located which then target and kills the pathogens.
List the signs and symptoms of sepsis, and explain the importance of infections that develop into septic shock.
Sepsis is an infection of the blood.
Fever
Respiratory rate increases.
Heart rate increases(tarchycardia).
Infections that develop into sepsis c
Why are hyperbolic chambers effective in treating gas gangrene?
Because it contains a pressurized oxygen-rich atmosphere. The oxygen then saturates the infected tissues of the obligately anaerobic clostridia.
Tetanus
Toxin Bacterial
Bacterial toxins are toxic substances that are produced and released by bacteria to target other bacterial or host cells.
How does the skin aid in protection of human body?
What are the layers of the nervous system?
What are the characteristic of the blood brain barrier
Stages of disease
Incubation phase
period between infection and prodromal.
No signs or symptoms .
Prodromal stage.
Mild symptoms
Period of illness-
most severe signs and symptoms .
if the body’s immune response is unsuccessful deaths can occur.
Period of decline-
signs and symptoms decrease
Convalescence stage
no signs and symptoms .
body returns to normal.
Acquired Immunodeficiency is resulted from what?
Variety of drug, cancers, infectious diseases.
What is considered the point of no return in an HIV infection?
Integration of viral RNA into chromosomal DNA in the cell’s nucleus.
What are the graft complications?
Graft rejection, graft infection, and graft vs host disease.
What are the necessary components needed for an HIV virion to bind to a CD4 cell?
CD4 receptor, Gp120, and Gp41
What is considered the window period for HIV?
Time period between infection and antibody production.
With what drug was P. notatum replaced by and why?
It was replaced by P. chrysogenum because it was a more prolific strain.
What is drug synergism and what is drug antagonism?
Synergism is when two drugs work together to enhance the effect. Antagonism is when two drugs inhibit the effects of each other
Why can you not take Cephalosporins if you are allergic to Penicillins?
Cephalosporins have the same “nucleus”, which is the beta-lactam ring. If you are allergic to penicillins, then you are most likely allergic to cephalosporins.
What does Sulfamethoxazole and Trimethoprim inhibit and why do they not hurt us?
They inhibit folic acid as result inhibiting DNA/RNA and protein synthesis. They do not harm us because we can get folic acid via our diet.
If a drug is selective, what does that mean?
mean that it specifically targets the bacteria cells and not the human cells.
Commensalism -
one benefits, one isn’t harmed/ not affected (+/0) (ex: bacteria lives off dead skin)
Mutualism -
both benefit from living together (+,+) (e.coli synthesis vitamin k and vitamin B)
Pathogenicity-
one organism benefits, the other is harmed (+/-) , causing disease in the host.
What is the difference between an acute and latent infection?
Latent is dormant or recessive and chronic is ongoing and long term.
Acute is sudden and severe.