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Microbiology Test 1 2

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What are the three Kingdoms
Eukarya, Bacteria, Archaea
Who studied the DNA within each kingdom
Carl Woese
Who discovered microorganisms and in what year?
Van Leeuwenhoek, 1674
Who created the small pox vaccine?
Jenner
what year did Jenner create small pox vaccine?
1796
From what realization did Jenner create the small pox vaccine?
using the fact that woman maids who had cow pox did not get small pox
Who established the cause of childbedfever and in what year?
Semmelweiss, 1847
How did Semmelweiss establish the cause of childbedfever?
Med. Students did autopsies and then delivered babies...encouraged washing of hands
Who disproved the spontaneous generation of microorganisms theory and in what year?
Pasteur, 1859
What is spontaneous Generation?
The idea that living organisms can arise spontaneously from non-living matter
Who set out to prove spontaneous generation and in what year?
Needham, and English clerygman, 1748
Why did Needhams covered boiled broth in flask still grow microorganisms?
Flasks were dirty
Who was the Italian priest/professor who poured broth into flasks, sealed them, and then boiled the broth to ensure clean flasks and in what year?
Spallanzano, 1776
When nothing grew in Spallanzano's flask, what did others say?
People argued that microorganisms needed oxygen and experiment was flawed
When nothing grew in Spallanzani's flask, what did others say?
People argued that microorganisms needed oxygen and experiment was flawed
Who is the father of modern microbiology
Louis Pasteur
How did Pasteur disprove spontaneous generation?
Boiled broth, air was allowed in, but microbs and dust settled in the S(swan) neck experiment...nothing grew
Who introduced aseptic techniques? What year?
Lister, 1865
Who established the germ theory of disease...linkeage between germs and diesease? What year?
Koch, 1876
Who uses agar to obtain a pure culture? What year?
Koch, 1881
Who discovered viruses and in what year?
Iwanowski, 1892
How did Iwanoski discover viruses
Used a filter that filtered out bacteria and realized that something smaller was still there that caused disease.
What instrument allowed us to see viruses? What year?
electron microscope, 1930
Who described selective toxicity...drugs such as chemotherapy and in what year?
Ehrlich, 1894
Who discovered penicillin, the first antibiotic? What year?
Fleming, 1929
Who discovered archaea? What year?
Carl Woese, 1977
In what year was small pox eradicated worldwide
1977
Who described pions? What year?
Prusiner, 1982
What are prions?
Proteins that cause disease
Who discovered HIV and in what year?
Montaigner and Gallo, 1983
Who sequenced the first complete genome of Haemophilus influenzae? What year?
Craig Ventner et al., 1995
Before the 19th Century, what were the three causes of disease considered to be?
Supernatural forces, poisonous vapors, imbalances between four humors
What were the four humors?
Blood, phlegm, yellow bile, and black bile
What is today's biggest problem concerning drugs?
Antibiotic resistance
What are some newly developed diseases?
SARS, hepatitis C, Lyme Disease, HIV
What are some re-emerging drug resistante diseases?
Tuberculosis, cholera, malaria, staphylococcus, typhoid fever
What is a strain?
A subgroup within a species
What are three differences between strains?
Morphology, physiology, antigenic properties
What are antigenic properties
foreign proteins (usually) that are expressed by a cell and recognized by the immune system
How are different strains designated?
By number and/or letters, ex. Esherichia coli 0157:H7
What three things are atoms made up of?
Protons, electrons, neutrons
What is the difference between covalent bonds and ionic bonds?
Covalent-shared, ionic-transfer
What kind of bonds hold water molecules together?
polar covalent bonds
What kind of bonds are present between water molecules?
Hydrogen bonds
What does polymer mean?
Many parts
What are polymers built from?
Repeating units called monomers
What does polymerization mean? And what are some examples of polymers?
formation of, nylons, proteins, DNA
Approximately how much dry weight of the cell do proteins make up?
>50%
Name three functions of proteins.
antibodies grab antigens, enzymes, transfer
What are proteins built from?
Amino acids
What are the components of an amino acid?
NH_2_, COOH, and an R-group (variable group)
What are peptide bonds and what do they do?
C-N bonds that link amino acids (proteins) together
What does the primary structure of a protein tell us?
the number and type of amino acid
What does the secondary structure of a protein tell us?
Where the amino acids are located, determines where the chain folds (created by bonding between amino acids)...alpha helices or beta sheets held together by H-bonds.
What is a tertiary structure?
folding of helical pattern
What is a quaternary structure?
2 or more polypeptide chains stuck together
Are mistakes in primary structures a problem? Why?
Yes, because structure determines shape and shape determines function
Give an example of how a mistake in the primary structure can change the function of a protein.
Hemoglobin; lactase
Give two examples of carbohydrates
polysaccharides and sugars
What are two functions of carbohydrates?
membrane structures and energy and energy storage
Give two examples of monosaccarides, simple sugars.
Glucose, fructose (candy)
Disaccarides are two monosaccharides: two glucoses equal...
maltose
glucose + fructose =
sucrose (table sugar)
glucose + galactose =
Lactose
What are polysaccharides?
polymers of many monosaccharides
What are some examples of polysaccharides?
starch (potatoes), cellulose (plants), glycogen (bacteria energy storage)
Where can polysaccharides be found in bacteria?
Cell walls
Give three examples of lipids:
fats, steroids (Cholesterol), and phospholipids
Give two functions of lipids
Energy storage/provision, cell membrane
Phospholipids in cell membranes have hydro____heads and hydro____tails
philic, phobic
Which fatty acid has a double bond and as a result less H-atoms and a kink in its structure, saturated or unsaturated?
unsaturated
What are nucleic acids (four things)
DNA, RNA, polymers of nucleotides, nucleotides
What are the three parts of a nucleotide?
5-carbon sugar (ribose or deoxyribose), phosphate group, and nitrogen base
What are the four nitrogen bases?
adenine, guanine, cytosine, thymine (uracil)
DNA is ____stranded, RNA is ____stranded, DNA has thymine, RNA has...
double, single, uracil
What are the three kinds of RNA?
Messenger, ribosomal, and transfer
Cell Envelopes contain these two or sometimes three parts:
cytoplasic membrane, cell wall, and sometimes outer membranes
The cytoplasmic membrane of a bacteria contains these 5 things:
phospholipid bilayer, peripheral proteins, integral proteins, hydrophilic phosphate heads (polar) and hydrophobic lipid tails (nonpolar)
What is the function of the membrane proteins?
allows uncharged molecules to diffuse unassisted across the lipid bilayer
What is facilitated diffusion?
diffusion through the interior of a channel or carrier protein, no enery boost required: concentration gradient differences
When a solute is pumped through the interior of carrier proteins, requiring energy input, this is called...
active transport
What is group translocation?
active transport (only in some prokaryotes) where molecules are simultaneously transported in and chemically altered...phosphorlylated
Why is group tranlocation useful?
because it uses less energy to bring in because concentration gradient is less deep
Describe the cytoplasmic membrane of ARCHAEA?
composition depends on habitat, phospholipids, sulfolipids, or glycerolipids, bilayers or monolayers
Inclusion bodies, located in the cytoplasm, are used for:
energy storage (glycogen, phosphorus), photosynthesis, magnetosomes, endospores (form inside cells and allow them to have a dormant life stage)
Where is the chromosome location?
Nucleoid
Protein synthesis occurs in the
ribosomes
Enzymes are also found in the...
cytoplasm
What is a virulence factor?
a microbial product or feature that contributes to pathogenicity, but not always the cause of disease symptoms
An example of a virulence factor among Streptococcus mutans is:
its capsule adheres it to a tooth
(mutans also have lactic acid which breaks down enamel and causes cavities
The cell walls of bacteria are made of these three things:
peptidoglycan (murein), a glycan portion, and a peptide portion
The glycan portion of the cell wall in bacteria consists of:
alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)...both sugar molecules
The peptide portion of the cell wall in bacteria:
connect adjacent NAMs
Are NAGs involved in bonding in peptide portion of cell walls?
NO
Bacteria differ in how many layers of NAG/NAMs, true or false?
True
Name four types of bacteria shapes:
cocci, Bacilli/Rods, Spirillum and other
What part of the bacterial cell prevents is from rupturing from osmosis?
cell wall
What are the three steps of binary fission?
grow, replicate, divide
How do autolysins aid in cell wall growth?
they break peptidoglycan bonds
How do transpeptidases aid in cell wall growth?
they add monomers and reseal the breaks that the autolysins make
How does penicillin work?
It prevents transpeptidase function (won't add monomers and cause bursting) in growing cells only because non-growing cells are not using autolysins
Lysozyme enzymes can be found where and what can they do?
tears, saliva, mucus, breaks the bond between NAM/NAG
What does selective toxicity mean and give examples
kils or inhibits pathogens with minimal damage to the host, penicillin and lysozyme because we don't have petido glycan or divide like that
Do Gram + bacteria have a thick or thin layer of peptidoglycan?
thick
Where does electron transport occur?
periplasm
Periplasm is:
the space between cell wall and cell membrane
Do Gram+ bacteria have a small or large periplasm?
small
Gram + bacteria have these two acids:
teichoic and lipoteichoic
Three examples of Gram+ bacteria:
Staphylococcus aureus, Bacillus anthracis, Clostridium tetani
Do Gram- bacteria have a thick or thin layer of peptidoglycan?
thin
Do Gram- bacteria have a large or small periplasm?
large
In Gram- bacteria, the periplasm contains...
the cell wall
There are teichoic acids in Gram- bacteria. True or False.
Flase, no teichoic acids
What characteristic of Gram- bacteria sets them apart from others?
presence of an outer membrane
What is the function of the outer membrane and what is it made of?
Layer of protection, lipopolysaccharide
Which are more resistant, Gram+ or Gram- bacteria?
Gram-
3 examples of Gram- bacteria:
Escherichia coli, Salmonella typhi (typhoid fever, Shigella spp. (intestinal diseases)
The inside layer of the outer membrane is made of______ and the outside layer is made of________.
phospholipids, lipopolysaccharides
Because the outer membrane is semi-permeable, it can block...
antibiotics, bile salts, and detergents
What are the two components of a lipopolysaccharide?
O polysaccharides and lipid A
What does lipid A do?
Simulates the release of cytokines, part of the immune system leading to an increase in temperature that will destroy what makes you sick
Is lipid A an endotoxin or an exotoxin?
Endotoxin...a part of the outer membrane vs. an exotoxin which a cell sends out
How can we differentiate between G+ and G- cells?
Gram stain
What are the four steps of Gram staining?
1. Crystal Violet Stain, 2. Gram's iodide, 3. Alcohol, 4. Safranin (counterstain)
The crystal violet stain stains what, what color?
peptidogylcan of all cells purple
Gram's iodide binds to this and traps it in the cell wall
crystal violet
Why is the alcohol step so important?
You can only rinse long enough to wash away CV entirely from G-'s (because their layer of peptidoglycan is thinner) and incompletely from G+'s
After the counterstain (Safranin), the G-'s will stain____ and the G+'s will stain_____.
pink, purple
What two reasons could explain a false Gram-?
rinse too long with alcohol, or if culture is too old (over 24 hrs.) because peptidoglycan layer can break down.
How could you explain a false positive?
Don't rinse long enough
Do acid-fast bacteria have a G+ or G- cell wall?
G+
The outside layer of peptidoglycan in Acid-fast bacteria is name of these two things:
later of polysaccharide and it's defining characteristic: mycolic acid
Why is mycolic acid a virulence factor in Acid-fast bacteria?
along with waxy lipid causing hydrophobia, makes bacteria extremely resistant to chemicals and hard to kill
Give two examples of Acid-fast bacteria:
Mycobacterium leprae and tuberculosis
What is unique about mycoplasms?
They are bacteria with no cell walls
What type of bacteria live in humans, animals, and plants where osmotic conditions are controlled for them?
Mycoplasms
Archael cell walls, of the domain archaea, depend on where they live..they are highly adaptive. They use this instead of murein...
pseudomurein
In Archael cell walls, this is replaced by a different sugar:
NAM
Name three things outside the cell envelope of most bacteria?
capsules, pili, and flagella
What are capsules made of?
most made of polysaccharide, some of protein
What is the function of a capsule?
protection and attachment
Capsules can attach to:
lung tissue, teeth, etc.
Capsules also provide protection from (two things):
drying out (in an environment during moving), and phagocytosis by macrophages (being eaten by white blood cells)
A capsule is a virulence factor because:
only encapsulated strains are pathogenic (disease causing)
What are pili?
thin, straight, hair-like projections of variable number
What are pili made of?
proteins called pilins
What are the functions of pili?
attachment, adhesion molecules (protein) and reproduction (sex pili)
Fimbriae can be a virulence factor because in Neisseria gonorrhoeae if:
there are no fimbriae, they are not pathogenic
Fimbriae can be a virulence factor because if in Escherichia coli...
there are no fimbriae it will colonize the large intestine, but if there are some strains with fimbriae, they will colonize in the small intestine
What is the purpose of flagella?
stiff, locomotion appendage
What are the three components of the Flagellin structure?
helical filament, hook, and basal body
What are the 3 jobs of the basal body:
anchoring ring, cytoplasm motor, rotating rod
What is the difference between flagella in Gram- and Gram+?
Gram- has two more anchoring ring structures because of the outer membrane
What is the difference between monotrichous, amphitrichous, lophotrichous, and peritrichous?
mono= one flagella, amphi=lots on one side, lopho=lots on both sides, peri= lots all around
What is movement due to chemicals, magenetism, and light called?
chemotaxis, magnetotaxis, and phototaxis
How do Helicobacter pylori use their lophotrichous flagella as virulence factors?
they corkscrew through gastric mucus layer, attech to epithelial cells of stomach lining, the mucus layer thins cause stomach epithilial cells to be exposed to acid causing ulcers and stomach cancer
Are flagella in eukaryotes similar to those in prokaryotes? If not, how different?
No, much different, arose separately, microtubules, whip-like motion
What are bacterial endospores and in which type of bateria do they exist?
dormant life stage of some G+ bacteria
Describe the structure of the bacterial endospore.
core: DNA and ribosomes
Cortex: peptidoglycan
Spore coat: layer of protein
What are the three stages of bacterial endospores?
vegetative cell, endospore, free-spore
Describe the cycle of an endospore.
a vegetative cell in conditions of low nutrients undergoes DNA rep., elongationand forms an endospore-->free spore which hangs out until times are good then is germinated through water, a particular nutrient, or damage to the spore (enzymes digest spore coat), and grows into a vegetative cell again
Why are endospores so hard to kill?
heat, radiation, chemical, and cold resistant (virulence factors). Made up of <15% water (enzymes do better when there is low water), DNA repair enzymes, calcium dipicolinate (stabilizes DNA)
Is the formation of an endospore reproduction?
NO, does not lead to an increase in cell number
What is the difference between Eukaryote and Prokaryote growth?
Eukaryotes: increase in size, Prokaryotes, increase in cell numbers
What are the steps in binary fission?
a vegetative cell undergoes DNA replication, elongation, chromosomes separate, and a cross wall forms
How does the baterial population reproduce so fast?
Large surface area to volume ratio...can take in a lot of stuff all the time...large surface to acquire nutrients, small volume requires relatively smaller amts. of nutrients
What four factors influence generation time?
Nutrients available, environmental conditions, genetics, community interactions
What are 7 things required for growth?
Energy, Carbon, Electrons, nitrogen, phosphorus, sulfur, and growth factors (chemical substances the microorganisms cannot synthesize)
In the Carbon category, if CO_2_ is required, then it is _________ and if organic carbon is required, then it is _________
an autotroph, a heterotroph
In the electron category, litho (rocks) = ______ and oragnotrophs =__________.
inorganic chemicals, organic chemicals
In the energy category, photo = ____ and chemo = _______.
light, inorganic or organic chemicals
Ex. photolithoautotrophs: cyanobacteria; purple and green sulfur bacteria
require light for energy, CO_2_ for their carbon source, and inorganic chemicals for their electron source
Ex. chemolithoautotrophs: nitrifyig bacteria, iron-oxidizing bacteria
require inorganic or organic chemicals for their energy, inorganic chemicals for their electron source, and CO_2_ for their carbon source
Ex. Chemoorganoheterotrophs: most human pathogens
require inorganic or organic chemicals for energy, organic chemicals for eletrons, and organic carbon for their carbon

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