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Microbiology 1
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140
Microbiology
Undergraduate 1
11/21/2009

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Term
PCR = Polymerase Chain Reaction
Definition
technique where we amplify DNA millions of time to investigate it
Term
Mycobacterium Tuberculosis
Definition
bacteria that causes tuberculosis
Term
Treponema Pallidum
Definition
Bacteria that causes Syphilis. Has a helical shape.
Term
Glycolcalyx
Definition
external polysaccharide (sugar) made inside the cell and excreted outside to form either a capsule or a slime layer
Term
Role of Capsule
Definition
Organized structured layer that protects the pathogenecity of the cell. Capsules help pathogens escape phagocytosis.
Ex: Streptococcus Pneumonia
Term
Role of Slim Layer
Definition
Non-organized non-structured viscous gelatonous polymer that helps in attachment of pathogen.
Ex: streptococcus mutans (cavities on teeth)
Term
Flagella
Definition
a whip-like structure external to the bacterial cell that is responsible for the movement of the cell by propelling it. Made of filaments, a Hook and Basal Bodies
Term
Flagella Filaments
Definition
Globular proteins called Flagellin
Term
Flagella Hook
Definition
Wide structure composed of different proteins anchored to the cell wall and plasma membrane by the Basal Body
Term
Flagella Basal Bodies
Definition
Disks that anchor the hook
Term
Axial Filaments
Definition
Appendages called Filamentous Fibrilis that wrap themselves around the bacteria and give it a cock-screw like motion
Term
Fimbria and Pili
Definition
Shorter, thinner, straighter hair-like structures than Flagella present all over the cell made of a protein called Pillin.

Some bacteria have sex pilli which are responsible for DNA transfer from one cell to the other.
Term
Bacterial Cell Wall
Definition
Macronetwork complex of Peptidoglycans forming a lettuce

Formed of alternating units of disaccharides (N-Acetylglucosamine and N-acetylmuramic acid) connected by peptide bonds.
Term
Peptidoglycans
Definition
Peptido = peptide
glycans = polysaccharides

Due to the alternating polysaccharides and the peptide bonds that connect them

due to the alternating polysaccharides and pepeti
Term
Function of Cell Wall
Definition
To protect the cell from rupturing when the water pressure inside the cell increases.

Gives shape and rigidity to the cell
Term
Peptidoglycan structure in Gram + bacteria
Definition
a carbohydrate backbone made of alternative polysaccharides of NAG and NAM linked together by tetrapeptide side chains and peptide cross bridges
Term
Peptidoglycan structure in gram -ve bacteria
Definition
Complex structure.

The Peptidoglycan and periplasmic space are sandwhiched in between the plasma membrane and the outer membrane. The peptidoglycan and outer membrane form the cell wall.

The outer membrane is formed of a phospholipid bilayer.

The outer membrane has lipopolysaccharides on its surface, mainly O polysaccharide and Lipid A (endotoxin)
Term
Cross Bridge Peptide and Tetrapeptide side chain
Definition
two types of peptides that link 50-60 units of alternating NAM and NAC together to form the carbohydrate backbone of the cell wall
Term
Gram Positive Bacterial Cell Wall
Definition
Contain many layers of peptidoglycan and Teichoic acid
Term
Teichoic Acid
Definition
Negatively charged phosphtate groups in gram positive bacteria that has two functions

1) Regulating the movement of rations inside and outside the cell
2) contain the antigenic specificity of the organism
Term
Gram Negative Bacteria Cell Wall
Definition
Formed of peptidoglycan and outer membrane
Term
Outer Membrane of Gram Negative Bacteria
Definition
Consists of phospholipids and lipoproteins and porin proteins

Porin proteins act as a channel for material like amino acids and vitamins

Lipopolysaccharides are the O Polysaccharides (contain the antigenic specificity) and Lipid A (endotoxin that causes fever upon infection)
Term
Which is stronger? gram -ve or +ve?
Definition
Gram +ve is rigid and has many layers of peptidoglycans so its stronger than the gram negative which is very fragile.
Term
Periplasmic Space
Definition
Space between the plasma membrane and outer membrane that contains all enzymes needed to break down nutrient material and generate ATP.
Term
Describe the Plasma Membrane
Definition
Phospholipid bilayer with a hydrophillic phosphorous polar head and hydrophobic lipid content. Proteins in the bilayer allow selective permeability. The Proteins and phospholipid bilayer of the plasma membrane give it a fluid-like mosaic structure.
Term
Function of the Plasma Membrane
Definition
Selective permeability and degredative enzymes that degrade nutrients. Also protects prokaryote by stopping certain antibodies from entering.
Term
Bacterial Cytoplasm
Definition
Viscous semi-transparent material that contains 80% water and enzumes, sugars and inorganic material. Remember that bacteria dont have any membrane bound organelles.
Term
Bacterial Nucleod Region
Definition
One circular DNA chromosome not associated with Histone proteins. It contains all necessary info for organisms to replicate
Term
Bacterial plasmid
Definition
A short piece of DNA that consists of a few genes and replicates on its own. It plays a role in antibiotic resistance and toxiginicity of the bacteria.
Term
Ribozomes
Definition
Is 70S molecular weight and made of two subunits, one 30 S and one 40 S. Its function is in protein translation.

Some antibiotics work on 30S, 40S or 70S ribozome to inhibit bacteria by stopping the translation of mRNA leading to bacterial death.
Term
Viral and Bacterial destruction
Definition
Medicating a viral attack is harder than a bacterial attack since in a viral infection need to destroy living cell while in bacterial infection need to destroy the bacteria.
Term
Sporulation
Definition
process of endospore formation
Term
Endospore
Definition
Formed inside bacteria and released, can survive heating process of food preperation and some disinfectants because of its many membranes. Mainly occurs in gram positive bacteria (Clustridium Botulinum, very potent exotoxin) and some gram negative (coxiella burnetii)
Term
S=
Definition
svdberg unit, relative sedimentation rate of the unit at ultrahigh speed centrifugation
Term
30S Ribozome subunit
Definition
Subunit is made up of a protein + 1 molecule of rRNA (Ribozomal RNA)
Term
40S Ribozome Subunit
Definition
Subunit is made up of a protein + 2 molecules of rRNA
Term
Bacterial inclusions
Definition
reserve deposits in cells
Term
Metachromatic granules
Definition
Inclusions: inorganic phosphates for ATP synthesis. Seen as red using Methylene Blue stain
Term
Polysaccharide granules (sugars)
Definition
Inclusions: starch and glycogen, use iodine stain to see
Term
Sulfur granules
Definition
Inclusions: needed for metabolism in some bacteria
Term
Carboxysomes
Definition
Inclusions: areas inside cell which contain enzyme ribulose-1,5-disphosphate carboxylase. Needed if cell uses carbon monoxide as energy source.
Term
Gas vacuoles
Definition
Area inside cell that maintains buoyancy and keeps the organism floating at a certain depth where theres enough light and nutrients for growth. Mainly for aquatic bacteria.
Term
Spores
Definition
some bacteria form spores, highly durable (can last thousands of years) dehydrated (no water) cells. Also known as resting cells. Sporulation occurs if a nutrient is missing, the bacteria revives if the nutrient is available.
Term
Eukaryotic flagella and celia
Definition
Short hairlike structures. if many, flagella, if few, celia. Gives the cell its wavelike movement
Term
Eukaryotic cell wall
Definition
Mainly sugars, not made of peptidoglycans.
- Algae: cellulose cell wall
- Fungi: cell wall n-acetylglucosamine (NAG) known as chitin
- Yeast: mannan (sugar)
Term
Eukaryotic Cell membrane
Definition
Its structure and function is similar to eukaryotes. Process of endocytosis (phagocytosis for solids and pinocytosis for liquid) and selective permeability
Term
Eukaryotic Cytoplasm
Definition
Complex structure of rods (microtubules) or cylinders (microfilaments) responsible for transport of material inside the cell, cytoplasmic streaming.
Term
Euakryotic Nucleus
Definition
Nuclear envelope is made of double layer and holes. Contains 1 or 2 nuceleoli to synthesize rRNA.
Term
Eukaryotic DNA
Definition
DNA associated with histones and other proteins. If cell is in a resting phase, the DNA and protein are condensed chromatin. If cell is dividing they are uncondensed chromosomes.
Term
Eukaryotic Endoplasmic Reticulum
Definition
Flattened sacks known as 'cisternae' whose function is lipid synthesis. Consists of the Rough Endoplasmic Reticulum (RER, many ribosomes) and the Smooth Endoplasmic Reticulum (SER, no ribosomes)
Term
Eukaryotic Golgi Apparatus
Definition
stack of dishes which receive lipids and proteins, sort them out and excrete them through vesicles
Term
Eukaryotic Mitochondria
Definition
Equivalent to chloroplast in plant cell, it is the energy house of the cell. Check figure. It has its own DNA which replicates from cell DNA without affecting the cell
Term
Eukaryotic Lysosomes
Definition
Prokaryotes and Eukaryotes, powerful digestive enzymes. Only membrane bound organelle that has a single membrane and not a double membrane.
Term
Eukaryotic vacuoles
Definition
In plant cells, vacuoles takes up 90% of cell space. It is the dumping place for waste products and water storage.
Term
Eukaryotic Centrioles
Definition
Next to nucleus, pair of short axies perpendicular to long axis. Function in mitosis and meiosis and a role in synthesis of flagella and celia.
Term
Metabolism
Definition
The sum of all chemical reactions taking place within an organism
Term
Metabolic Chemical Reaction
Definition
Catabolic chemical reaction: release energy, degredative, due to breakage of the organic bonds

Anabolic reaction: Acquire energy, biosynthetic, building organic bonds
Term
Mechanism of ATP use in Metabolic reactions
Definition
Coupling of energy release and energy usage using ATP to build and degrade organic compounds.

Release energy: ATP --> ADP + :P + Energy

Consume Energy: ADP + :P + Energy --> ATP
Term
Role of Enzymes
Definition
All metabolic reactions can only take place in the presence of enzymes. Catalysts speed up the reaction without themselves being changed. They are specific and mainly consist of proteins.
Term
Describe Enzymes
Definition
Consist of a protein part (epoprotein or epoenzyme) and Non protein part (metallic ion or complex inorganic molecule)
Term
NAD+
Definition
Nicotineamide Adenine Dinucleotide. Has an important role in catabolic reactions
Term
NADP
Definition
Nicotineamide Adenine Diphosphate. Important role in anabolic reactions.
Term
NAD+ and NADP are
Definition
derivatives of nicotine acid or vitamin B. Both function as electron carriers.
Term
Carbohydrate Catabolism
Definition
Energy releasing pathway (catabolic reaction)that most microorganisms use to oxidize carbohydrates as their main source of energy.
Term
Respiration
Definition
Energy releasing pathway that uses glucose to produce ATP. When balanced, theoretically releases 38 ATP
Term
3 classes of molecules that are involved as electron carriers in respiration
Definition
Flaviproteins and Flavin (derivatives of B12)

Cytochrome (protein and iron binding for heme molecules)

Coenzyme Q though not a protein carrier
Term
Alternative Pathway
Definition
Catabolic reaction that is needed for catabolism of 5 carbon sugars needed in synthesis of NADP. Involves the Pentose Phosphase Shunt.

gram -ve bacteria use the Duodordoff pathway
Term
Fermentation
Definition
A biological pathway that doesnt need oxygen to occur but can occur in its presence. The endpoint can be any other molecule, differs with different species. Number of ATP produced is much less in fermentation than in respiration. . The first step in fermentation is glycolysis, which yields Pyruvic acid.
Term
Lipases
Definition
Extracellular enzymes produced by microbes that split lipids into other compounds
Term
Lipids in metabolic reactions
Definition
lipids are made of glycerol and fatty acids. When they are split, they go into Krebs cycle which is involved in the oxidation of glycerol and fatty acids
Term
Proteases and Peptidases
Definition
Extracellular compounds produced by microbes that split proteins into components (amino acids)
Term
Proteins in metabolic reactions
Definition
After broken down into amino acids, amino groups undergo deamination where ammonium ions (NH4+) are excreted outside the cell and what remains goes into the kreb cycle
Term
Biosynthesis of Carbohydrates
Definition
Carbon atoms which are needed for the synthesis of glucose come from intermediates of glycolysis and krebs cycle
Term
Metabollic pathways of energy use
Definition
anabolic or biosynthetic reactions
Term
Glucose to Pyruvic Acid
Definition
Glucose --> Glyceraldehyde-3-Phosphate --> Glucose 6 Phosphate ---> Fructose 6 Phosphate --> Pyruvic acid
Term
Glucose 6 Phosphate in anabolic reactions
Definition
In bacterial cell, Adenosine Diphosphate Glucase (ADPG) synthesizes several units of this compound to form glycogen. This is a form of dehydration synthesis that requires ATP
Term
Fructose 6 Phosphate in Anabolic reactions
Definition
UDPNA (Uridine Diphosphate Nacetyl Acid) synthesizes severl subunits using UTP to produce peptidoglycan (Bacteria)
Term
Lipid biosynthesis
Definition
anabolic reaction for the formation of lipids, usually uses precursors of glycolysis
Term
Glyceraldehyde 3 Phosphate in lipid biosynthesis
Definition
Glyceraldehyde 3 phosphate become dihydroxyacetone phosphate which becomes glycerol and that combines with fatty acids (from pyruvic acid) to form lipids. Requires energy but not necessarily ATP.
Term
Biosynthesis of Protein
Definition
Some microbes have enzymes necessary to break certain precursors to form the amino acids required (Like E Coli). Microbes that dont have these enzymes cant break down amino acids.
Term
Amination
Definition
Addition of an amino group to organic acids
Term
trans-amination
Definition
Amino group added from another amino acid
Term
Biosynthesis of Nucleic Acids
Definition
RNA and DNA are made up of nucleotides, purines and pyramidines (the C and N atoms come from amino acids glycine, glutamine, and aspartate) and pentose (sugar) and phosphorous group (from ATP)
Term
Amphoteric Pathway
Definition
Whenever a pathway has a dual function in catabolism and anabolism
Term
Generation time
Definition
time to double the number of bacteria in a culture
Term
Binary Fission
Definition
an inward dip in plasma membrane and cell wall

1- Elongation of cell and replication of DNA
2- The cell wall and plasma membrane move inward to region where DNA was replicated
3- Complete separation of DNA and cell wall
4- 2 daughter cells are identical to the mother
Term
Budding
Definition
Some bacteria replicate by budding, which is a small outgrowth on one side of the cell which keeps it growing till the outgrowth is identical to the mother cell. Cell wall and plasma membrane expand.
Term
Spore Formation
Definition
some bacteria, particularly filamentous bacteria, make spores at the end of or underneath the filament (spore chain). These spores grow up to form new bacteria.
Term
Ways of bacterial reproduction
Definition
-Binary Fission
-Budding
-Spore Formation
Term
REMINDER
Definition
study eam question on page 2 of notes OCT30
Term
Stages of Bacterial Growth
Definition
1) the Lag Phase
2) Log Phase
3) Stationary Phase
4) Death Phase or Decline
Term
Lag Face
Definition
First stage of bacterial growth: From 1 hr to 3 hr, the number of bacteria stay the same. Bacteria is undergoing intensive metabollic activities particularly synthesizing DNA and enzymes
Term
Log phase
Definition
Second phase of bacterial growth, T=4.5 hrs, number of bacteria start to increase
Term
Constant Phase
Definition
Number of bacteria become constant, stage of equilibrium where number of dividing cells equals the number of dying cells.
Term
Death Phase
Definition
Toxic waste excreted from dying cells, pH becomes very acidic and very few bacteria grow in an acidic medium
Term
Chemical Requirements for Bacterial Growth
Definition
Water, oxygen, carbon, minerals (sulfer, phosphorous), organic growth factors, and trace elements
Term
Physical requirements for Bacterial Growth
Definition
Temperature, pH, osmotic pressure
Term
Affect of Temperature and Bacterial Growth
Definition
- -10o --> 10/20o => cold loving bacteria or Psychrophiles

- 20o --> 40-50o => Moderate, mesophiles

- 50o --> 70o => heat loving bacteria, theriophiles

- 70o --> 100-120o Hypothermophiles/volcanic activities, hot springs. these bacteria usually need sulfur for metabolism.

Best temperature is body temperature, 37oC
Term
Effect of pH on Bacterial Growth
Definition
Optimal pH is 6.5-7.5 in the neutrality zone, plus phosphate buffers to maintain pH.
Term
Acidophilic Bacteria
Definition
grow at a very low pH
in stomach, pH=2, enterobacteria
in coal mines, pH=1
Term
Effect of Osmotic Pressure on Bacterial Growth
Definition
Plasmolysis occurs when concentration of solutes outside the cell is more than enside, so water leaves the cell to the environment causing cell shrinkage.
Term
Important Chemicals for Bacterial Growth
Definition
- Water
-CO2 needed as a source of Carbon for the carbon backbone
- Ammonium ion needed as a source of nitrogen for protein synthesis and amino acid source
- Sulfate, some bacteria need sulfur
- Phosphorous needed for ATP, phospholipids, purines and pyrmadines from Phosphate ion
Term
importance of Trace Elements in Bacterial Growth
Definition
trace elements Zn, Fe, Cu and Mg mainly work as cofactors.
Term
Organic Growth Factors
Definition
- Trigger growth of the cell, provided from environment,
- used in synthesis of vitamins and some amino acids.
Term
Strict Anaerobic Bacteria
Definition
Don't need oxygen at all to grow and will die in the presence of oxygen
Term
Aerotolerant bacteria
Definition
Mainly grow at bottom, in the absence of oxygen, but can be found on the surface
Term
Facultative Bacteria
Definition
Can grow in the presence or absence of Oxygen, though they prefer O2. if its not available, they can use other.
Term
Microaerophillic Bacteria
Definition
Need O2 but less concentration than aerophillic so usually found in the middle
Term
Culture Media
Definition
Nutrient material used for the growth of microbes in the lab
Term
Agar
Definition
A nutrient material (extracted from seaweed) that acts as a solidifying agent for the growth of bacteria
Term
Advantages of using Agar:
Definition
1) Very few bacteria degrade Agar
2) Becomes solid at 40o and remains solid at 100o
3) When poured on innoculum, doesnt hurt or kill bacteria
Term
Chemical Media
Definition
Well-defined chemicals that only need hydration (addition of water). The media provides a source of energy and all required nutrients for bacterial growth
Term
Complex Media
Definition
Made up of yeast extract, meat extract, peptones (short chains of amino acids) and provides a source of energy and nutrients.
Term
Selective Media
Definition
Suppress growth of certain bacteria and allow for the growth of needed bacteria

Bismuth Sulfate in media will suppress gram +ve and only allow gram -ve interic bacteria

Sabouroid Dextrose allows only the growth of fungi at pH 5.6
Term
Differential Media
Definition
Differentiates between closely related bacteria and allows bacteria to grow but allows you to differentiate between them.

Bloos Agar allows the growth of all streptococcus but differentiates between Strep. Pyogenes from others since only this bacteria hemolysis the blood
Term
Selective and Differential Media
Definition
Selects growth of certain microorganisms and also differentiates between others

MacConkey suppresses the growth of gram +ve and allows gram -ve to grow
+ bile and crystal violent --> only allows the growth of enteric gram -ve

+ Lactose
If bacteria ferments lactose --> pink color
If bacteria doesn't ferment lactose --> colorless colony
Term
Enrichment Media
Definition
Used when the desired microorganism is present in small numbers. Selective and increases the number of microorganisms every time they are subcultured in a solution media.
Term
Reducing Media
Definition
Made for Anaerobic bacteria.

Uses Sodium Thioglycolate which reacts with oxygen and removes it from the media. Provides an anaerobic atemosphere for the growth of anaerobic bacteria
Term
Characteristics of a Culture Media
Definition
- Right nutrient and right amount of nutrient
- Sufficient moisture
- Provide sufficient O2 is aerobic growth is required
- Properly adjusted pH
- STERILE
Term
Deep Freeze Bacteria Culture
Definition
Suspend pure bacteria in culture in suitable media. Freeze quickly at -50o-->-90o and the bacteria can survive for years while frozen. Thaw the specimen and culture it again-->bacterial growth
Term
Lyophilization
Definition
Freeze dry the bacteria and freeze it at -70o, then vaccuum out air and water through a special pump and seal it with high temperature. This powderizes the culture so it can survive for many years and be recultured.
Term
Preservation of Viruses
Definition
Liquid Nitrogen
Term
Sterilization
Definition
Destruction of all forms of life including endospores. Best method is using heat.
Term
Disinfection
Definition
The destrcution of the vegetative pathogens (all the bacteria except endospores) using a disinfecting agent
Term
Antisepsis
Definition
When the killing of vegetative pathogens is applied to living tissues using an antiseptic agent.
Term
Degerming
Definition
Mechanical removal of germs from an area using an alcohol swab
Term
Sanitization
Definition
Reducing the number of organisms to minimize infection using sanitizing agent.
Term
Requirements of effective microbial treatment
Definition
- Degree of contamination
- Time of exposure
- Type of microorganism
- Environmental factors: pH, temperature, presence of organic matter
Term
Heat as a method of control of Bacterial Growth
Definition
Dry Heat (open flame) and Moist Heat (Autoclave)
Term
Moist Heat
Definition
Boiling for 10 minutes is enough to kill most microbes but not endospores.

As the pressure increases the temperature the microbes are exposed to increases.
Term
Autoclave
Definition
Sterilizes using pressurized steam, especially used on surgical equipments and when theres an AIDS patient
Term
Pasterization
Definition
Different degrees of heat to sterilize

Classic 63o for 30 mins
HTST (High Temp Short Time) 72o for 15 mins
Ultra High 100o for 1 minute
Term
Thermal Death Time
Definition
Length of time to kill all microbes using dry heat
Term
Thermal Death Point
Definition
The temperature at which all bacteria are killed within 10 minutes
Term
Low Temperature in Bacterial Growth
Definition
Doesnt kill but inhibits growth of microbes
Term
HEPA - High Efficiency Particulate Air
Definition
Machine used in hospitals to filter out bacteria and viruses depending on the filter used, especially for patients in isolation unit.
Term
Plasmolysis as a Growth Control
Definition
Injcrease of salt in a solution with bacteria causes plasmolysis and cell shrinkage but not death
Term
Dessication to control bacterial growth
Definition
Remove water to control growth of bacteria
Term
Radiation to control bacterial growth
Definition
Very effective way of killing bacteria using Xray, gamma waves or UV light
Term
Chemical means to control growth of bacteria
Definition
Ethylene Oxide is a penetrating chemical mainly used on AIDS patients
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