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MCB Exam 2
Dr.Ashgari Exam 2
250
Microbiology
Professional
02/26/2011

Additional Microbiology Flashcards

 


 

Cards

Term
What are the 5 kingdoms?
Definition

1. Animal

2. Plant

3. Monera

4. Protozoa

5. Fungi

Term
What are the 3 domains for microorganisms?
Definition
1. Small Eukarya
2. Archaea
3. Bacteria
Term
Why are viruses in a class of their own?
Definition
Because they are not complete cells.  They have no membrane, no regulation, cannot replicate on its own.
Term
What is spontaneous generation? And who disproved it and how?
Definition

The rise of living from the non living. 

Pasteur and Koch = Germ Theory of Disease

Term
Who was the first to see and define microbes; defined the cell?
Definition
Robert Hooke
Term
Who is responsible for discovering immunizations?
Definition
Edward Jenner
Term
Who is the creator of Penicillin?
Definition
Alexander Fleming
Term
Why is Paul Ehrlich a major contributor to the science of microbiology?
Definition

He found the cure for syphilis.  Found out that Salvarsan chemical killed the spirochetes.

"Magic Bullet" that targets the site of infection

Term
Who is the father of microbiology and why?
Definition

Louis Pasteur

Did the swan- neck flask experiment and developed the Germ Theory of Disease that states that there is a germ behind every disease. 

Found the causes for Tb, anthrax, cholera, and rabies.

Term
What are the 6 major bioelements?
Definition

1. Carbon

2. Hydrogen

3. Sulfur

4. Oxygen

5. Nitrogen

6. Phosphorous

 

(SPONCH)

Term
What are the 4 polymers all life forms have? What are there building blocks?
Definition

1. Lipids  = Fatty acids + glycerol

2. Protein = Amino Acids

3. Nucleic Acids = Nucelotides (Base/Sugar/PO4)

4. Carbohydrate (Polysaccharides) = Sugars

Term
Which carbohydrate source is most abundant on earth?
Definition

Cellulose

(but cant be digested by humans because of the B 1,4 bond)

Term
What are carbohydrates used for in the body?
Definition

1. Structural units

2. Energy

3. Important in the cell membrane they can attach to lipids and proteins on surface then can serve as receptors

Term
What is the difference between saturated and unsaturated lipids? And which is more fluid?
Definition

Saturated = More hydrogens, no double bonds

 

Unsaturated = More double bonds, less hydrogens (MORE FLUID because the double bonds tilt the molecule so it dont compact well)

Term
Which is the most abundant polymer?
Definition

Protein

 

It accounts for 55% of dry weight of cells

Term
What is a polymer?
Definition
A repeat of similar or identical monomers
Term
What are the 3 categories of chemical reactions?
Definition

1. Synthesis = Anabolism = Dehydration

2. Decomposition = Catabolism = Hydrolysis

3. Exchange = no net gain/loss of water

Term
_____________ is part of the bacterial cell wall whereas ___________ is in fungal cell walls.
Definition

Peptidoglycan

Chitin

Term
This type of reaction occurs spontaneous and releases energy, whereas ______________ requires energy input.
Definition

Exergonic

Endergonic

Term
What are some functions of proteins in cells?
Definition

1. Enzymes

2. Regulate cellular processes

3. Structural support (ex: collagen)

4. Surface receptors (ex: glycoprotein)

5. Carriers

6. Transmembrane proteins that are involved in signal transduction

Term
What type of bonds contribute to the primary structure of a protein?
Definition

~ 300 A.A connected by peptide bonds (a form of covalent bond)

 

The NH2 from 1 A.A attachs to the COOH from another A.A

Term
What types of bonds make up the secondary structure of proteins? And what do they make?
Definition

Held together by H-bonds between the A.A along with there peptide bonds from their primary structure. 

 

Alpha helix and Beta Sheets

Term
The tertiary structure of proteins results from what kind of bonds/forces?
Definition

1. Disulfide bonds (S-S = covalent bond)

2. Hydrophobic interactions

3. Van Der Waals interactions

Term
This structure is when the protein becomes functional: ____________
Definition
Tertiary (3D shape)
Term
What gives proteins its biological properties and what things affect the protein structure?
Definition

Folding gives its properties

 

Temp (can melt H bonds)

pH (can affect polarity/charge)

Term
What are the 2 different types of microscopes and there magnification strength?
Definition

1. Compound Light microscope = 1000-2000x magnification

 

2. Electron microscope = 100,000x Magnification

Term
Which type of compound light microscopy is best for Ab-Ag interactions and is a good tool for detecting infectious disease? What is its source of illumination?
Definition

Fluorescent

 

UV light

Term
What are the 2 types of Electron microscopy you can have?
Definition

SEM = surface of cell

TEM = cross section of the cell

Term
When would you use electron microscopy?  And what is its light source?
Definition

It is good for detail of individuals structures, you can even view viruses. 

 

They use electron beam as the light source

Term
What is smear preparation?
Definition
Heat fixing cells so that they dont get washed off during the staining procedure
Term
What are some different stains that you can do?
Definition

1. Simple stain = one color

2. Differential stain = 2 colors

3. Negative stain = stain the background

Term
What are 2 important differential staining procedures?
Definition

1. Gram Stain

2. Acid fast stain

Term
When do you do an Acid Fast Stain?
Definition
Used with Mycobacterium because they have a thick waxy coat that doesnt absorb color from a stain.  Used to determine TB/Leprosy if results in a positive Acid fast stain.
Term
Structural stains involve staining of these structures: _____________, _____________, _____________
Definition

Flagella

Endospore

Capsule

Term

What is the relative size of microbes?

What about RBC and Eukaryotes?

Definition

Micro = 0.5 to 2.0 microns

RBC = 7.5 microns

Euk = 20 microns

Term
Give an example of a gram positive cocci that is in clusters.
Definition
Staphylococcus
Term
Give an example of a gram positive cocci in a chain?
Definition
Streptococcus
Term
Give an example of a gram negative cocci.
Definition
Gonorrhea
Term

What types of shapes do the following have:

1. Cocci

2. Bacilli

3. Spirillum

4. Spirochete

Definition

1. Spherical

2. Rod

3. Spiral

4. Coil

Term
What are some examples of gram positive bacilli?
Definition

Bacillus (anthrax)

Clostridium (tetanus, botulinum)

Term
What are some examples of gram negative bacilli?
Definition

1. E. Coli

2. Salmonella

Term
Which is the most famous spirochete?
Definition
Syphilis
Term
Give an example of a spirillum?
Definition
Cholera
Term
Cholera is a ____________ borne disease.
Definition
Water
Term
T/F:  Endospores are found in both Pro and Euk.
Definition
False, only in Pro
Term
T/F:  Peptidoglycan is only found in Eukaryotes (in plants).
Definition
False; Only in Prokaryotes
Term
What is the endosymbiosis theory?
Definition
That organelles such as Mitochondria and Chlorplast evolved from symbiotic prokaryotes living in other prokaryotes.
Term
What 3 things make up the glycocalyx? And what does glycocalyx aid in?
Definition

1. Capsule

2. Extracellular Polysaccharides

3. Slime layer

 

In the formation of the biofilm

Term
Microorganisms are divided up into 2 groups depending on the structural component of their cellular envelops. What are these 2 groups?
Definition

Gram +

Gram -

Term
What 2 sugars make up the cell wall?
Definition

NAG = N-acetylglucosamine

NAM = N-acetylmuranic Acid

Term
Describe the cell wall and cell membrane of a gram positive cell.
Definition

1. Many layers of peptidoglycan

2. No outer membrane

3. Contains Teichoic and Lipoteichoic acid

4. No Lipopolysaccharrides (LPS)

 

Term
Describe the cell wall and cell membrane of a gram negative cell.
Definition

1. Few peptidoglycan layers

2. Has an outer membrane

3. Has a Periplasmic space btwn the outer and cytoplasmic membrane

4. Has LPS

5. Has no techoic acid

6. Has porins for entry of molecules

Term
Describe the process of Gram staining.
Definition

1. Primary stain with a crystal violet

2. Add a mordant (Iodine) to intensify the primary stain

3. Decolorize via Alcohol or Acetone

4. Counterstain with a secondary stain - Safarin

 

RESULTS

Gram + retain the primary color cause of thick walls so they are purple

Gram - lose the primary color after decolorizing and are red/pink due to the counterstain

Term
T/F: Gram + are red where as Gram - come out violet after a gram staining procedure.
Definition

False, it is the opposite

+ = violet

- = red

Term
Mycoplasma is a type of bacteria that lack what?
Definition
A cell wall
Term
______________ destroys cell walls.
Definition
Lysozymes
Term
If you have a higher amount of ______________ than you are more _____________ to lysozymes so an example of this would be a gram ______ cell.
Definition

Cell wall

sensitive

+

Term
What is the fluid mosaic model?
Definition

Biological membranes are a 2D liquid made up of lipids and proteins that diffuse more or less easily than others.  PHOSPHOLIPID BILAYER

SEMI PERMEABLE

Term
T/F:  Polar and Ionic substances can easily diffuse across a membrane.
Definition
False; only nonpolar, uncharged molecules can cross readily
Term
Facilitated Diffusion still does not require energy but it does require specific binding of the nutrient to a _________________ where it causes a _______________ in the protein which results in the release of the nutrients in the _____________.
Definition

Facilitator protein

Conformational Change

Cytoplasm

Term
In Simple diffusion/Passive and Facilitated Diffusion there is an _______________ amount of nutrients inside and outside the  cell.
Definition

Equal

(Equilibrium)

Term
Active Transport is  ______________________ that concentrates nutrients ____________ the cell.
Definition

Energy Dependent

Inside (1000x more than outside)

Term
What is the energy source for active transport?
Definition
The Proton Motive Force
Term
What 2 things make up the PMF?
Definition

1. Proton Gradient

2. Charge Gradient

Term
What is PTS?
Definition

Phosphotransferase System

 

Gluc comes into the cell and gets PO4+ via PEP

(is highly regulated)

Term
T/F:  Since H2O is polar it does not cross the membrane freely.
Definition
False; it is the only polar substance that can cross readily thru the membrane
Term
What makes up metabolism?
Definition

Catabolism = releases energy

Anabolism = uses that energy to make new cells

Term
There are 2 different types of culture medias, what are the they and the difference between the 2?
Definition

Defined = You know the exact # of material and you need a buffer to maintain pH

 

Undefined (complex) = You dont know the # and is uses proteins derived from plants and animal extracts as the buffer

Term
Why are enzymes used in reactions?
Definition
They are used to lower the activation energy needed to start the rxn, this increases the rate of the rxn.  Enzymes work by bringing the substrates closer together or by making them interact more.
Term
Metabolism usually involves ___________ of highly ____________ food sources (sugars), extracting energy and storing it in the form of ____________.
Definition

Oxidation

Reduced

ATP

Term

Lose Electrons = ___________

Gain Electrons = ____________

Definition

Oxidation

Reduction

 

(LEO the lion says GER)

Term
Oxidation and Reduction reactions are always _____________ and use _____________.
Definition

Coupled

Electron Carrier Proteins

Term
What are the 3 main electron carriers?
Definition

1. NAD+---------> NADH

2. NADP+-------> NADPH

3.  FAD-------> FADH2

Term
What is the definition of phosphorylation?
Definition
Adding organic PO4 to a substrate
Term
What are the 3 ways cells can phosphorylate ADP to ATP?
Definition
1. Substrate Level Phosphorylation (SLP)
2. Oxidative Phosphorylation
3. Photophosphorylation
Term
Where does SLP occur?
Definition

In Glycolysis (makes PEP first)  and the Kreb Cycle (makes succinly CoA)

 

 

Term
In ______________ the reduced molecules are oxidized and the energy is extracted by the ___________.
Definition

Oxidative Phosphorylation

ETC

Term
What is an electron acceptor?
Definition
A molecule that accepts electrons and in the process becomes reduced!
Term
What is the Chemiosmosis Theory?
Definition

1. Membrane maintains electrochemical gradient

2. Cells use energy released in redox rxns of ETC to make PMF

3. H+ propelled by PMF, flow down electrochemical gradient via ATP Synthases to make ATP

 

 

AKA Oxidative Phosphorylation because proton gradient created by oxidation of components of ETC

Term
What are 3 ways to reoxidize the electron carriers? And which is most preferred method?
Definition

1. Anaerobic Respiration

2. Aerobic Respiration (most preferred)

3. Fermentation

 

 

Term
In Glycolysis, Glucose is ___________ to make _____ Pyruvate, and _____ ATP while at the same time reducing ____ NAD+ to make NADH.
Definition

Oxidized

2

2

2

 

Term
During fermentation NADH is reoxidized to NAD+ by using ATP from ____________ and forms _______ and _______ as end products.
Definition

Glycolysis

Alcohols

Acids

Term
What happens during Cellular Respiration?
Definition
Pyruvic Acid is completely oxidized to make ATP after a series of redox rxns
Term
Under Aerobic conditions, Pyruvate is converted to _________ and ___________ via the enzyme ____________.
Definition

Acetyl CoA

CO2

Pyruvate Dehydrogenase

Term
What is decarboxylation, and how many in the Kreb cycle?
Definition

The release of CO2

There is 2 CO2 released

Term
What are examples of high energy compounds?
Definition

1. Succinyl-CoA

2. ATP, ADP

3. PEP

Term
T/F:  The Krebs Cycle occurs in the matrix of the mitochondria in prokaryotes and in the Cytoplasm for Eukaryotes.
Definition

False;

Prokaryotes = Cytoplasm

Eukaryotes = Mitochondrial Matrix

Term
What is an amphibolic pathway? Give an example!
Definition

Amphibolic = Can be used for both anabolic and catabolic processes

 

Example = Glycolysis and Kreb Cycle

Term
What happens during Aerobic Respiration?
Definition

1. Regenerate NAD+ and FAD

2. Pump H+ out of cell, but comes back in via ATP Synthetase, this creates PMF

3. Make lots of ATP

4. O2 is reduced to H2O

Term
What is the first enzyme in the ETC and what is the final electron acceptor?
Definition

1. NADH Dehydrogenase

2. O2

Term
In Anerobic Respiration, since there is no O2 what is used as the final electron acceptor?
Definition
Inorganic molecules such as Nitrates, Nitrites, Sulfates and Carbonates
Term
What is the difference between fermentation and anaerobic respiration?
Definition

In Fermentation there is no Kreb Cycle or ETC

It uses an organic molecule as the terminal e- acceptor and makes ATP via SLP.  It also only make 2 ATPs

 

Anaerobic Respiration = Occurs with the ETC but different e- acceptor than O2.  It uses inorganic molecules and makes ~ 34 ATPs

Term
Which mechanisms generate ATP using an ETC?
Definition
Both Anaerobic and Aerobic Respiration
Term
Which process makes the most ATPs thus is the most efficient mechanism?
Definition
Aerobic Respiration
Term
What type of process is it if you require the use of a proton gradient across the membrane to make ATP?
Definition

Oxidative Phosphorylation

(aka chemiosmosis)

Term
What are the products of the Krebs Cycle?
Definition

2 ATP

2 FADH2

4 CO2

6 NADH

Term
What are some similarities between Aerobic and Anaerobic Respiration?
Definition

Both undergo Glycolysis, Krebs and ETC

ATP is made via Oxidative Phosphorylation

Electron carriers are re-oxidized

Term
Phototrophs use the _________ as their energy source whereas chemotrophs use _______________.
Definition

Sun

Oxidation of organic/inorganic compounds

Term
Autotrophs use ____________ to fix CO2 whereas Heterotrophs use ____________ as there carbon source.
Definition

Inorganic compounds

Organic compounds

Term
T/F: Photoautotrophs use both the energy from the sun and CO2 fixation as their carbon source.
Definition
True
Term
Enzymes are ____________that are not used up during a reaction, so they can be reuused!
Definition
Organic Catalysts
Term
Enzymes are made up of an ______________ (protein portion) and a ______________ (non protein portion). Together they make up the ______________.
Definition

Apoenzyme

Cofactor or Coenzyme

Holoenzyme

Term
What is binary fission?
Definition
As a cell grows it divides into 2 new cells.
Term
What device measures the increase in cell mass which thus can determine the growth rate?
Definition
Spectrophotometer
Term
What is the generation time? And when is it measured?
Definition

 It is the amount of time it takes for the bacteria to 2x

 

Measured during the log phase

Term
What are the 4 different growth phases?
Definition

1. Lag Phase

2. Log Phase

3. Stationary Phase

4. Death/ Log Decline Phase

Term
What happens during the lag phase? Log phase? Stationary phase?  Death phase?
Definition

Lag phase = acclimation, where preparation occurs and the synthesis of necessary enzymes

 

Log phase = Exponential growth where you get the max rate of growth

 

Stationary phase = Waste builds up and the # of cells dividing = # cells dying

 

Death phase = cell death

Term
Define growth curve?
Definition
It is growth of a bacteria due to an increase in cells in a population not there size
Term
If you have a higher ____________ than your Optical Density is ________ which means there is ____________ bacteria.
Definition

Absorbance

higher

more

Term
What are the cardinal temperatures of growth?
Definition

1. Hyperthermophiles: grow at 80 C

2. Psychrophiles: grow at 20-40 C and 0 C

3. Mesophiles: Optimal growth at 37 C

Term
How does Temp and pH affect microbial growth?
Definition

Temp: if 2 hi or low can denature protein by affecting H bonds

 

pH:  Changes enzymatic activity by changing the shape of the protein

Term
Acidophiles grow best at _________.
Definition
Very low pHs
Term
In which ways can Facultative Anaerobic organisms maintain life?
Definition

1. Fermentation

2. Anaerobic Respiration

3. Aerobic Respiration

Term
In order for obligate anaerobes to grow there must not be any __________ present.
Definition
Oxygen
Term
Aerotolerant Anaerobes dont undergo aerobic metabolism but they do have enzymes that do what?
Definition
Detoxify the poisonous forms of Oxygen
Term
What products arise following oxygen metabolism?
Definition

Formation of oxidizing agents such as:

Superoxides

Peroxides

Free radicals

 

(All can lead to cell damage)

Term
What are microaerophiles?
Definition
Aerobes that need only a little bit of Oxygen (2-10%) and can only detoxify the byproducts of oxygen metabolism to small extent
Term
Which type of organism growth condition the most efficient?
Definition
Facultative Anaerobe - they can undergo all 3 processes
Term
Give an example of an obligate anaerobe?
Definition
Clostridium--- causes gangrene
Term
What occurs in a Hypotonic solution?
Definition
Water moves into the cell and may cause the cell to burst if the wall is weak/damaged (osmotic lysis).  There is a lower solute concentration on the outside of the cell.
Term
What happens in Hypertonic solution?
Definition
Water moves out of the cell causing the plasma membrane to shrink (plasmolysis).  There is a greater solute concentration outside the cell.
Term
What is the difference between selective and differential media?
Definition

Selective = select on group against others

Differential = Different groups will grow in different colors

 

If fermentation has occured the pH will b lower. Use phenol red indicator to determine when fermentation has occured.

Red = 7 Pink = 9 and Yellow = 5

Term
What is made after transcription?
Definition
mRNA, rRNA, and tRNA
Term
Translation is the process of making _____________
Definition
Proteins from mRNA
Term
What are some major differences between RNA and DNA?
Definition

1. Ribose vs Deoxyribose

2. Uracil vs Thymine

3. single stranded vs double stranded

Term
DNA replication occurs in the _________ direction so DNA Polymerase adds nucleotides to this end ________.
Definition

5' -----> 3'

 

3' OH end

Term
Because DNA is antiparallel, this creates a ______________ strand and a ____________ strand.  Which has continous replication?
Definition

Leading (continous)

Lagging

Term
Why does DNA form a double helix?
Definition
Because of the H bonds between complementary base pairs
Term
What do they mean by DNA is Semi-Conservative?
Definition
There is one old strand (parent) and one newly synthesized strand (daughter)
Term
Because Bacteria has circular DNA, where do they know to start replication?
Definition
At the ORI (origin)
Term
How are errors corrected in DNA replication?
Definition
DNA Polymerase has proofreading abilities.  it has a 3' to 5' exonuclease activity that removes wrong nucleotides
Term
Which enzyme is responsible for transcribing RNA from DNA?
Definition
RNA Polymerase
Term
T/F: RNA  Polymerase needs a primer.
Definition
False; it doesnt need a primer, but it does need a DNA template
Term
Compare RNA Polymerase to that of DNA Polymerase.
Definition

1. Lacks proofreading activity

2. Does not need a helicase

3. Does not need a primer

4. Slower

5. Puts in U instead of T

 

Term
Where is the site of protein synthesis?
Definition
The ribosomes
Term
What is the definition of an operon?
Definition
A cluster of genes under one comman/control
Term
What is an inducible operon and give an example?
Definition

It is normally off, and it has to be activated by an inducers.  This type of operon controls catabolic enzymes

 

Ex: Lactose Operon.  If no glucose then turned on because there is high # of lactose

Term
What is a repressible operon? Give an example
Definition

It is normally on and transcribed continually until it is deactivated by repressors.  This type of operon controls anabolic enzymes.

 

Ex: Tryptophan operon.  If Tryp is present then operon is turned off

Term
Ribosomes are made up of ____________ and _____________ and vary in size in Pro vs Euk.
Definition

Protein

RNA

Term
What are some important features of the genetic code?
Definition

1. Universal

2. Remains unchanged

3. Start codon = AUG (Methionine)

4. Stop codon = UAA, UAG, UGA

Term
T/F: Every codon codes for a specific A.A. but an A.A can have more than codon because of degeneracy.
Definition
True
Term
Why do bacteria have an advantage of simultaneous replication, transcription and translation?
Definition
Since they have no nucleus, all processes are coupled and occur at the same time.  This gives it a faster rate and there is no need for post transcriptional modification
Term
What is a Frame-Shift Mutation?
Definition
A change in the reading frame of the DNA due to an insertion/ deletion.  This can lead to a partially folded protein, a missense or a nonsense where there is no protein made.
Term
What is a mutagen?
Definition
Anything that causes a mutation (that is a heritable chnage in DNA)
Term
Why is radiation consider a mutagen?
Definition

If its ionizing then it induces breaks in both strands that are hard to repair in chromosomes.

 

If its nonionizing then it could still form thymine dimers

Term
What are some examples of chemical mutagens?
Definition

1. Nucleotide analogs

2. Nucleotide-altering chemicals

3. Frameshift mutagens

Term
A Nucleotide analog looks like a NT but does not function normally it disrupts DNA and RNA replication and causes _____________.
Definition
Point mutations
Term
Nucleotide-altering chemicals result in _____________ and ___________ mutations.
Definition

Base-pair substitution

Missense

Term
Frameshift Mutagens result in _______________.
Definition

Nonsense mutations

 

no protein is made

Term
How does DNA repair occur?
Definition

All repairs via DNA Polymerase

 

Finds error, removes it, fills gap with correct base.

Term
T/F: Carcinogens are harmful chemicals or agents that can cause cancer due to mutations in the DNA
Definition
True
Term
In light repair photoactivation opens  ______________ whereas in dark repair this occurs _____________.
Definition

Thymine dimers

 

The wrong base is removed and is replaced with a new base

Term
What is the Ames Test used for?
Definition
Used to look at bacterial DNA to help screen for substances that might cause cancer.  It looks at metaboolic activity being affected by mutation (damage) to DNA
Term
In the Ames test, if _______________ is present then there is a carcinogen present.
Definition
Histidine
Term
What is genetic recombination?
Definition
It is the exchange of DNA segments composed of homogolous sequences
Term
What is vertical gene transfer?
Definition

Organisms replicate their genomes and then pass it down to the next generation.

 

Example from parent to daughter

Term
What is horizontal gene transfer?
Definition
A donor contributes part of their genome to recipient.
Term
List and define the 3 types of Horizontal Gene transfer.
Definition

1. Transduction = DNA is transfered with the help of viruses

2. Transformation = cells pick up DNA from lysed cells

3. Conjugation = Donor transfers plasmid to recipient via pilli

Term
Why use Recombinant DNA Technology?
Definition

To modify genomes of organisms by natural and artificial processes for practical processes.

 

You can eliminate unwanted phenotypes

Combine beneficial traits to make  a valuable organism

Make products that humans need

Term
What are some tools used in Recombinant DNA Techonology?
Definition

1. Mutagens

2. Reverse Transcriptase

3. Restriction enzymes

4. Vectors

5. Synthetic nucleic acids

6. Gene libraries

Term
What are vectors? And list some useful properties.
Definition

Vectors are tools for inserting DNA into a host.  They can be viruses, plasmids, transposons

 

They are small enough to make in lab

Can survive inside the cell

Contain gene markers that are recognizable

Ensure genetic expression of gene

Term
What is a gene library?
Definition
A collection of bacterial or phage clones; each contains a piece of the genetic information of interest
Term
List some examples of techniques used in Recombinant DNA Technology.
Definition

1. PCR

2. Separation of DNA molecules

3. Insertion of DNA into cells

4. Clone Selection

Term
What is PCR?
Definition

Polymerase Chain Reaction

 

Used for multiplying/ amplifying DNA in vitro

 

(Was used for West Nile virus and Bacilius Antracis to ID the source of spores)

Term
What are ways to separate DNA molecules?
Definition

1. Gel electrophoresis = separate based on charge, size and shape

(the smaller the faster it will travel)

 

2. Southern Blot

Term
What are some natural methods of inserting DNA into cells?
Definition

1. Transduction

2. Transformation

3. Conjugation

 

Can use vectors

Term
Describe the artificial methods for inserting DNA into cells.
Definition

1. Electroporation = Make the membrane more responsive

2. Protoplast fusion = fuse 2 cells membranes

3. Injection = gene gun and microinjection

Term
What are the applications for Recombinant DNA technology?
Definition

1. Genome mapping

2. Drug development

3. Vaccine Development

4. Agricultural applications

5. Provides info on metabolism, growth

6. Relate DNA sequence to protein synthesis

7. Transgenic organisms

Term
List 3 incidents over the last century that brought infectious diseases under control.  What did they control?
Definition

1. Establishment of Health Department in 1900s = Made water treatment systems that controlled Cholera

 

2. Creation of antibiotics = Controlled Pneumonia

 

3. Vaccinations = Eradicated smallpox

Term
What are common types of diseases in the United States?
Definition

1. STDs

2. Upper Respiratory Disease

3. Gastroenteritis

Term
What are some of the common infectious diseases in developing countries?
Definition

1. AIDS

2. Respiratory Diseases

 3. Intestinal Diseases ( virus = rotavirus, bacterial = Salmonella, Campylobacter)

4. Deseases caused by lack of Immunization = Tetanus

Term
What is MRSA?
Definition

Methillicin Resistant Staphylcoccus Aureus

(The pathogen is resistant to the antibiotic)

This is a 2 billion dollar problem in hospitals and accounts for 20000 deaths a year.

Term
What is the name of the flesh eating bacteria?
Definition
Streptoccocus Pyrogenes
Term

What is a nosocomial infection?

What are some contributing factors?

Definition

A disease acquired while in a hospital.

 

1. Old age, weakened Immune system

2. A breakdown of barriers (burns, cuts, etc)

3. Chemotheraphy

4. Antibiotic resistant bacteria

5. Get 1 infection every 14 extra days

6. 1/20 infected or 1/400 deaths = 20000/yr

7. 2 billion $ a year

Term
What are some causes for a nosocomial infection?
Definition

1. Patients are already ill, have impaired defenses

2. crowding = more infections

3. Most virulent forms are in hospitals

4. Newborns lack functional immune system

5. Drug resistant pathogens

Term

Which pathogens is most common in UTIs?

Which are most common in surgical infections?

Definition

1. E.Coli

2. Pseudomonas Aeruginosa

 

1. S. Aureus

2. Streptococcus

Term
Define disease
Definition
Abnormal condition or function
Term
What is an infection?
Definition
Growth of a microbe on or within a host (can be symptomatic or asymptomatic)
Term
What is a pathogen? And which 2 microbes are usually pathogens?
Definition

Bacteria capable of causing disease (only a small # are pathogens)

 

Usually: Mycobacterium Tuberculosis (TB)

and

Yersenia Pestis

Term
What is the definition of an opportunistic pathogen and what is the most common of them?
Definition

A pathogen that normally doesnt cause harm, but does so in immune compromised people.

 

Ex:  Pseudomonas Aeruginosa

Term
T/F: Virulence is the relative ability (degree) to cause a disease. So if you have a higher virulence then you are more likely to cause a disease.
Definition
True
Term

What is ID50?

What happens if you have a lower LD50?

Definition

ID50 = Infectious Dose 50

 

The number of organisms required to make 50% of the population sick

 

If LD50 is low then there is high virulence

Term
What is LD50? And what happens if you have a high LD50?
Definition

LD50 = Lethal Dose 50

 

Is the number of microbes that can kill 50% of the population that has the disease.

 

If LD50 is high then you have low virulence.

Term

State Koch's Postulates?

What does it prove?

Definition

1. Observation = Signs and symptoms

2. Isolation = Pure culture

3. Re-infection = in an healthy person

4. Re-Observation and Re-Isolation = compare

 

Proves the etiology of the disease. One disease from one microbe

Term
What are the 3 exceptions to Koch's Postulates?
Definition

1. Mycobacterium Leprae (leprosy) = grows to slow

2. Treponemma Pallidum (syphillis) = cant grow outside of host

3. Polymicrobic infections

Term
Describe the triangle of infection, starting with normal individuals at the top of the triangle.
Definition

Top: Normal individuals who are healthy . There are few microbes that are capable of causing disease. So here is there is hi LD50 and ID50

 

Side:  Individuals with impaired defenses

 

Bottom:  Immunocompromised individuals. Many microbes can cause disease. So here there is a low LD50 and ID50.  (ex: Chemo patients, HIV peeps, diabetes peeps, etc)

Term
What are the 2 ways bacteria can cause a disease?
Definition

1. Invasion

2. Producing toxic products

Term
List the degree of invasiveness.
Definition

1. No invasion

2. Minimal Invasion

3. Highly invasive

Term
Describe a non invasive infection and give an example.
Definition

It is highly toxic; usually food borne toxin

 

Ex:  Clostridium Botulinum

or

S. Aureus

Term
Describe a minimal invasive infection and provide an example.
Definition

Potent toxin

 

Ex: Corynebacterium Diptheria

or

C. tetani

Term
Describe a highly invasive infection and give an example.
Definition

Little or no toxin made

 

Ex:  Shigella

M. Tuberculosis

Term
What are the 3 steps involved in bacterial invasion?
Definition

1. Attachment

2. Obtaining nutrients

3. Avoiding host defenses

Term
_____________ determines host and tissue specificity.
Definition
Attachment
Term
What type of structures or macromolecules are used for attachment?
Definition

1. Proteins

2. Fimbriae

3. Pili

 

(Ex.  N. Gonorrhea has a specific pili for attachment)

Term
What nutrient is often a limiting factor?
Definition
Iron
Term

What do you call the Iron binding proteins in Bacteria?

What about in the host cells?

Definition

Bacteria = Siderophores (Is a virulence factor)

(used to try and steal the hosts Iron)

 

Host = Transferrin, Lactoferrin

Term
What is a protective mechanism that a host cell does in order to make Iron less available to a bacteria?
Definition
It will limit the amount of Iron circulating in the body and will transfer it to the liver
Term
In which ways do bacteria avoid the host defenses?
Definition

1. Avoid antibody

2. Avoid the phagocytic cells

Term
What 2 ways do bacteria avoid host antibody during invasion? And give examples of bacteria that do this.
Definition

1. Rapid antigenic change (changes it pili so wont recognize it)  - N.Gonerrhea, Borrelia

 

2. Precipitate Antibody by binding to Fc portion (inactivates it)  - Staphylcoccus Aureus

Term
In which 3 ways do bacteria avoid the action of phagocytic cells?
Definition

1. Leukocidins

2. Survival within the cell

3. Antiphagocytic capsule

Term
________________ attack phagocytic cells.  Which bacteria possess this?
Definition

Leukocidins

 

Staphyloccus Aureus

Term
Which type of bacteria are capable of surviving within a phagocytic cell?
Definition

1. Mycobacterium Tuberculosis

2. Salmonella typhi

Term
T/F: A capsule is a virulence factor.
Definition
True
Term
For both Exotoxin and Enterotoxin, entry is required and both are dimeric proteins. What does A do, What does B do?
Definition

A:  Required for toxic activity

B:  Required for entry into cell (you want antibodies to inhibit the attachment)

Term
Cytolytic toxins attack ______________ whereas ____________ affects normal nerve function.
Definition

Surfaces

 

Neurotoxins

Term
What is an Exotoxin?
Definition
Proteins that are produced and secreted by a microorganism.  They are highly toxic, nonpyrogenic and hihgly immunogenic. 
Term
What is a superantigen?
Definition
Toxic chemicals produced by bacteria that mimics multiple infections thus activating multiple T cells leading to an over reaction to one infection.
Term
What is an endotoxin?
Definition
Part of the gram negative bacteria outer membrane (LPS) and is only released once the microbe dies
Term
The Cytotoxin, S. Aureus has an alpha toxin that does what?
Definition
Disturbs the cell membranes ion channels
Term
Which organisms is responsible for cell death? How does it accomplish this?
Definition

C. Diphtheria

 

A portion of the dimeric protein inactivates the Elongation Factor 2 thus inhibits protein synthesis

Term
_______________ is a neurotoxin that masks the target muscle so that the neurotransmitter cannot reach it.  This leads to _______________ .
Definition

C. Tetani

 

Constant contraction (ex: lock jaw)

Term
This neurotoxin inhibits the release of neurotransmitters leading to constant relaxation.
Definition
C. Botulinum
Term
How does the enterotoxin, V. Cholera cause diarrhea/dehydration?
Definition

The A portion of the tetramer increases the adenylate cyclase activity thus increases cAMP.  The increase in cAMP increases the flow of ions out of the cell and thus water too. 

 

No antibiotics is need, just rehydrate

Term
During shock, what are some main things to look out for?
Definition

Fever

Hypotension

Term
What are routes of entry for infectious diseases? 
Definition

1. Mucous membranes (GI, Resp, Uri, Eye) 

2. Skin

3. Parenteral route

4. Vector Transmission

Term
What is a parenteral route for disease?
Definition

Entering the body by other means than the alimentary tract. 

 

Entry via subcutaneous, intramuscular, or IV

Term
What is vector transmission? Give an example
Definition

Entry via an insect

 

Ex:  Rickettsia Prowaskii = body lice

Term
What are the functions of pili?
Definition

They are aka adhesins. Specific attachment

Genetic exchange

Promote blood clotting

Prevent Phagocytosis

Term
What is flagella?
Definition

An organ for locomotion

aka H-antigen

Term
_____________ is made up of proteins and carbohydrates; causative agents of pneumonia and meningitis.  It is aka ____________.
Definition

Capsule

K Antigen

Term

What are virulence factors?

List the different forms of virulence factors.

Definition

Anything that facilitates a disease. Can be the prescence of the bacteria in the body, something the organism makes, or something it possess.

 

1. Pili

2. Capsule (K-Antigen)

3. Flagella (H-Antigen)

4. Cell Wall

 

Term
What are some ways phagocytic failure can occur? What are the organisms that do this?
Definition

1. Inhibit Phagocytosis = S. Pneumonia

2. Inhibit Lysosomal fusion = TB

3. Escape Lysosome = Plague

4. Lives w/in Lysosome = Salmonella

5. Kill Phagocyte = S. Aereus

Term
What is epidemiology concerned with?
Definition

Transmission, spread, control and prevention of infectious diseases in populations.

 

(All aspects of disease except treatment)

Term
What is the difference between endemic, epidemic and pandemic?
Definition

Endemic = Disease stays in pop at low frequency

Epidemic = Sudden outbreak in above levels
Pandemic = An epidemic over a wide area (worldwide)

Term
What is the difference between mortality and morbidity?
Definition

Mortality = Reported deaths due to the disease

Morbidity = All reported cases of disease;  illness + deaths

Term
___________________ is where a disease is typically found.
Definition
Reservoir
Term
Give some examples of reservoirs.
Definition

Inanimate

Animate = Humans (ex: gallbladder)

Carriers

Term
Compare and contrast the different routes of transmission of diseases.
Definition

1. Airborne-borne = Most common, travels > 1 m (ex: Cold, Flu, TB)

 

2. Anthropod- borne = Carried by vector (ex: Thphus fever from body lice)

 

3. Direct contact = STDs

 

4. Food-borne = Preformed toxins (ex: Botulinum)

 

5. Water-borne = ex: Cholera

Term
How do bacteria evade the immune system (antibodies, complement and phagocytes)?
Definition

1. Proteases = inactivate host defense

2. LPS = Lipid A stimulate cytokine release, damages host cells

3. Capsules = Prevent phagocytosis

4. Vary surface antigens = H and K

5. Superantigens = Excess cytokine production

6. Cross reactivity

Term
What is normal flora?
Definition
A form of commensalism where their is bacteria in us that benefit from us, and leaves no harm to the host. The organisms are associated with healthy body tissues.
Term
What is the normal flora on the skin? Which can tolerate high salt concentrations?
Definition

1. Staphylococcus - can tolerate it

2. Corynebacterium

Term
What organism breaks down enamel (hardest compound in body) by lowering the pH as it grows in the oral cavity?
Definition
Streptococcus Mutans
Term
Give some examples of normal flora in the mucous membranes.
Definition

1. GI = Lactobacilli

2. Small Intestine = Enterococci

3. Large Intestine = Entercocci

4. Upper Respir. Tract = Strep and Staph

5. Urethra = E. Coli, Proteus

6. Vagina = Lactobacilli

Term
What is symbiosis??
Definition
A close association between 2 microbes where both benefit from the association
Term
_______________ is an example of a symbiosis whereas paratism is an example of ____________.
Definition

Mutualism

 

Antagonism

 

Term
How is the skin an important barrier to infectious diseases?
Definition

It has natural defense mechanisms

 

1. High Salt concentration

2. Low moisture

3. Fatty acids

4. Low pH

Term
What is significant of the epidermis?
Definition

It has a tight layer of cells.  The top layer is dead cells that is constantly shedded.

Makes it hard for microbes to attach

Term
Compare and contrast prokaryotic and eukaryotic mRNA.
Definition

Eukaryotic mRNA have the following modifications:

 

5' Cap

3' Poly A tail

Introns removed

Term
What are plasmids? What are transposons?
Definition

Plasmids = DNA molecule that can separate independently of chromosomal DNA

 

Transposons = sequences of DNA that move within a genome

Term
What is significant of biofilm?
Definition
Is a virulent factor that protects the bacteria from the immune system.  Creates a sticky film around the bacteria.  Made from glycocalyx
Term
List some different forms of Adherence factors?
Definition

1. Glycocalyx

2. Adherence proteins

3. Lipoteichoic acids

4. Fimbriae (pili)

Term
Compare the intracellular and extracellular life of bacteria.
Definition

Intra = Microbes live inside cells where they are protected from Ab, phagocytes, etc. They dont move as much  (Ex: Chlamydia = obligate intracellular parasite)

 

Extra = Bacteria is in the blood not the cells. So they are constantly under attack, but have more motility

Term
Fimbriae are hair like structures used for ______ attachment whereas cilia is hair like projections that are used to ___________ in the respiratory tract.
Definition

non specific attachment

 

sweep away fluids/particles

Term
Lipoteichoic acid is only found in ___________ and can cause __________.
Definition

Gram +

Immune system activation

Term
T/F:  LPS is found on the outer membrane of gram + and act as endotoxins that stimulate an immune response.
Definition
False; LPS is only found in gram -
Term
What is the signficance of having capsule, endospores and flagella for the bacteria?
Definition

They are all virulence factors

 

Capsules = prevent phagocytosis

Flagella = locomotion

Endospores = Survive harsh conditions

Term
In which ways do bacteria avoid detection by the immune system?
Definition

1. Fast in, fast out

2. Mimic host antigens

3. Stay within host cells

4. Infect priviledge sites

5. Bind to host antibodies upside down

6. Antigenic variation

Term
Define RFLP
Definition

Restriction Fragment Length Polymorphism

 

It is the difference between samples of homologous DNA molecules that come from differing locations of restriction enzymes sites

Term
Define In Situ Hybridization
Definition
Uses labeled complementary DNA or RNA strand (probe) to localize a specific DNA or RNA sequence in a portion/section of tissue
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