MB 351 Exam 1

The system of nomenclature for organisms are scientific names that are

"latinized"

Electron wavelength

0.005 nm

Light resolution

0.2 micrometers

The limit of resolution for light microscope is

0.2 micrometers

The smallest object the human eye can see is about

0.2 mm or half a grain of salt

Electron resolution

0.2 nm

What is the average bacillus size?

0.5-1 micrometer wide by 1-4 micrometers long

An average coccus is about

0.5-1 micrometers in diameter

The simple microscope used by Aton Van Leeuwenhoek in the 1600s had how many lenses?

1

1 bacterium is about how long

1 micrometer

Spirals range in size from

1 micrometer to over 100 micrometers in length

marine microbes typically grow best between

1-4% NaCl

Typical glass has a reflective index of

1.5

Electron maximum magnification

100,000+

Light maximum magnification

1000 to 1500

How long did it take Europe's population to recover from the Black Death?

150 years

The 16S rRNA consists of

1542 bases and contains the substrate binding A-, P-, E- sites

The 30S subunit is composed of

16S rRNA and 21 ribosomal proteins

Light microscopes can visual a range of sizes from

200nm (.2 micrometer) to 10 mm

TEM gives you a

2D image with internal structures

Seawater contain how much NaCl

3%

Most natural environments have a pH between

3-9

1 m = ___ft

3.29

Scientists had evidence that cells first appeared on earth

3.8 to 3.9 billion years ago

Plasmids can contain 5-100 genes, but are usually less than

30

Robert Hooke's lenses achieved what fold power?

30-fold power

Prokaryotic ribosomes consists to two subunits denoted

30S (small subunit) and 50S (large subunit)

What is the 50S subunit made of

31 proteins, and 2 rRNA molecules, the 5S and 23S

The Black Death reduced the World Population from and estimated 450 million to

350 to 275 million

SEM gives you a

3d image with no internal structures

Eukaryotic ribosomes have two unequal subunits

40S (small subunit) and 60S (large subunit)

Light wavelength

530 nm

Estimates of total microbial cell numbers on earth are on the order of

5X10^30 cells

When the two subunits are joined together, the complete ribosome is the

70S, referring to the sedimentation coefficient in Svedberg units.

Eukaryotic ribosomes are also known as

80S ribosomes because they sediment faster than the prokaryotic 70S ribosomes

Mordant

A chemical which is added to the solution to intensify the stain. This may help to increase the affinity of the stain for the specimen

Overheating the organism in heat fixing causes what?

A distortion of the sample.

Capsule

A gelatinous covering meant to determine an organism's virulence

What are NAG and NAM linked by

A glycosidic bond with B-1,4 linage.

Lysozyme

A natural form of protection from gram-positive pathogens

What happens during protein synthesis?

A ribosome moves along an mRNA molecule, reading the codon and adding the correct amino acid (from the corresponding aminoacyl tRNA) to the growing protein. When the stop codon is reached, translation verses, and the mRNA and protein are released.

When the flagella motor goes CCW what occurs

A run

Chicken/Fowl Cholera

A serious, highly contagious disease caused by the bacterium Pasteurella multocida in a range of avian species includingg chickens, turkeys, and water fowl

What are Koch's postulates?

A set of rules and experimental procedures for the assignment of a microbe as the cause of a disease

Monotrichous

A single flagellum at one pole

Where is Y. Pestis naturally found?

A small type of rodent of Central Asia called a marmot

Pili gliding movemetn

A smooth gliding movement of myxobaceteria. It provides a means for microbes to travel in environments with low eater content such as biofilms and soil

Culture media

A solid or liquid preparation use to grow, transport and store microorganism. It is an aqueous solution to which all the necessary nutrients have been added

Twitching motility

A special "Type IV" pilus extend by the addition of subunits of piling. This makes contact with a surface or another cell and then retracts as the piling subunits are disassembled. This is called the grappling hook model of twitching and results in short, jerky, intermittent movements

Model organism

A species that has been widely studied, usually because it is easy to maintain and breed in a laboratory setting and has particular experimental advantages

Condenser

A substage lens which focuses the light on the specimens. Most condensers move up and down to focus the light beam

Antigen

A substance that elects antibody formation

In the 1950s and 1960s, the U.S. and Soviet Biological weapons programs developed techniques to directly aerosolize plague particles

A technique that leads to pneumonic plague, an otherwise uncommon, highly lethal and potentially contagious form of plague.

Lophotrichous and polar

A tuft of flagella coming from one pole

Describe the petri dish design

A two dish design that allows for gas exchange but prevent microbial contamination

Compound microscope

A type of light microscope which contains 2 lenses

Colony

A visible mass of microbial cells arising from one cell or from a group of the same microbes

What did Pasteur and his team announce they had discovered in April 1881?

A way to weaken anthrax viruses and so could produce a vaccine against it

Pathogenesis

Ability to cause disease

Needham's experimental design

After heating nutrient broth, he let a flask cool and sit at a constant temperature open to the environment for several hours. later the flasks would be sealed.

Slant cultures

Agar Media is poured into test tubes and allowed to solidify in an angled position so that the media has a "slant" to it allowing for greater surface area and inoculation on this slanted surface.

Who discovered Penicillin

Alexander Fleming

What is the poisonous ingredients in shellfish poisoning?

Algae-like organisms known as dinoflagellates which build up in some types of seafood

Cell Theory

All living cells are composed of cells and come from preexisting cells

What likely caused the microbial growth in Needham's experiment?

Allowing the broth to cool in an open container for several hours. The microbes in the air contaminated it leading to the microbial growth he observed

Lipid A serves as what when it is released?

An endotoxin

Capsules glycocalyx appearance

An extensive, tightly bound accumulation of gelatinous material adhering to the cell wall

Who does not have cell walls

Animal and protozoans

The acid-fast stain

Another type of differential staining which binds strongly to bacteria that have a way lipid material called mycelia acid in their cells

Phase contrast

Another way to observe living specimens and permits more detailed examinations of internal structures

The overall negative charge of the outer membrane of gram-negative cells protects the cell from

Antibiotics and limits the permeability of many compounds damaging to the cell

"Histone-like" proteins in

Archaea (prokaryotes)

Pseudomurein cell walls if

Archaea (prokaryotes)

Impacts of microorganisms

As agents of disease, environmental damage, microbial ecosystems, food production, agriculture, energy, biotechnology and model for basic science

How must specimens be prepared in TEM

As an ultra thing section or slices because the beam of electrons must pass through the sample to illuminate it. This gives you incredible internal detail of a cell or strucutre

What was leading to the collapse of the wine industry in France?

At the time, the wind industry of France was facing collapse due to problems with fermentation process leading to production of acidic byproducts and thus a sour taste.

Core Polysaccharide

Attached to lipid A and provides structural stability

Hook

Attaches to the filament. Is slightly wider in size than the filament

Yeast is particularly rich in

B vitamins

BSL 2:

BSL-2 builds upon BSL-1. If you work in a lab that is designated a BSL-2, the microbes there pose moderate hazards to laboratorians and the environment. The microbes are typically indigenous and associated with diseases of varying severity. laboratory personnel have specific training in handling pathogenic agents and are directed by scientists with advanced training; access to the laboratory is limited when work is being conducted; extreme precautions are taken with contaminated sharp items; and certain procedures in which infectious aerosols or splashes may be created are conducted in biological safety cabinets or other physical containment equipment.

Prokaryotes can be what shapes

Bacillus (rod), coccus (sphere)

Peptidoglycan (murein) cell walls if

Bacteria (prokaryotes)

There are no histones in

Bacteria (prokaryotes)

Examples of prokaryotes

Bacteria and Archaea

Anaerobe

Bacteria that doesn't utilize ozygen

All living organisms are classified into three domains of life

Bacteria, Archaea and Eukarya

What are the different types of microbes?

Bacteria, archaea, fungi, protozo, microscopic algae and viruses

Why are specimen visualized in brightfieqld microscopy?

Because of the differences in contrast (density) between the specimens and surroundings

Sterols

Believed to help protect mycoplasmas from lysis

The ability for glycocalyx to adhere to surfaces aids in what?

Biofilm formation and the ability to cause disease

What did Spallanzani's experiment show?

Biogenesis

What theory did Pasteur's experiment support?

Biogenesis

What theory does Redi's experiment support?

Biogenesis

What are some common features between prokaryotes and eukaryotes

Both have DNA as their genetic material, Both are covered by a cell (plasma) membrane, both contain RNA, Botha re made from the same basic chemicals (carbohydrates, proteins, nucleic acid, minerals, fats and vitamins, Both have ribosome, both regulate the flow of nutrients and wastes that enter and leave them, both have similar metabolism like photosynthesis and reproduction, both require a supply of energy and both are highly regulated by elaborate sensing systems ("chemical noses") that make them aware of the reactions within them and the environment around them

How did Pasteur's idea gain creditability?

By discovering that spoiled organisms could be inactivated in wine by applying heat at temperatures below its boiling point.

How does penicillin kill bacteria?

By interfering with the ability to synthesize the cell wall

How did Pasteur show the air was full of microorganisms?

By passing air through gun cotton filters. The filter trapped tiny parities floating in the air. By dissolving the cotton with a mixture of ether and alcohol, the particles were released and then settled to the bottom of the liquid. Inspection of this material revealed numerous microbes that resembled the typed of bacteria often found in putrefying media.

How was the incidence of Small pos decreased in countries of Asia and Africa?

By the practice of deliberately inoculating children with material from smallpox pustules

Both photoautotrophs and chemoautotrophs carry of the autotrophic process of

CO2 fixation

All cells consist mainly of

Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous and Sulfur

Chemical requirements for growth

Carbon, hydrogen, nitrogen, sulfur, phosphorous, micronutrients such as trace elements and growth factors, molecular oxygen (aerobes or anaerobes), various organic growth factors and water

Flagella special stain

Carnolfuschin

Rabies

Caused human victims to die a painful death and the disease appeared to be getting more and more common in France

Endotoxin

Causes an immune response in the host

Koch's third postulate

Cells from a pure culture of the suspected pathogen must cause disease in a healthy animal

Iron is the chief trace elements and it play a key role in

Cellular respiration by seeing as the redox center or function as cofactors in enzymes involved in electron transport reactions

Streptobacillus

Chain of rods

Streptococcus

Chain of spheres

What are the two broad classes of culture media?

Chemically defined and complex

In order to overcome these limitations of a batch culture, what might be set up

Chemostats

What is the increasing order of susceptibility of avian species with Chicken Cholera?

Chicken, turkey, water fowl

What are the three most common shapes of bacteria?

Coccus, bacillus and spiral

Capsules special stain

Colloids (india ink)

Biofilm

Community of microorganisms living within a shared mass of secreted slime.

Complex media

Composed of a mixture of proteins and extracts in which the exact chemical composition is poorly defined, often made of natural source components - red blood cells, yeast extract, peptone, Casein, etc. It is used as a non-specific medium for growing many organisms

Body tube

Contains mirrors and prisms which direct the image to the ocular lens

Focusing knobs

Control the up/down movement of the stage

Spiral

Corkscrew or curved

What are the two types of glycocalyx

Cpasules and slime layer

Staphylococcus

Custer of spheres

What is analyzed to reveal the ancient divergence of the 3 domains of living organisms?

DNA sequences (specifically rRNA gene)

Soil microbes

Decompose organic waste and incorporate N2 gas into organic compounds: recycling all thees chemical elements between soil, water and air

Virulence

Degree to which a pathogen can cause disease

Beef extract (meat)

Derived from infusion of beef and provides an undefined source of nutrients. A Mixture of peptides, amino acids, nucleotidesm organic acids, minerals and some vitamins.

Tactic (taxis response behavior

Directed cell movements in response to a stimulus

Dominant Concepts during the 17th and 18th Century Microbiology

Disease are caused by "poisonous" air (miasmas), Disease are transmitted by touch (contagions), Creatures like maggot, flies, toads and snacks, microbes are formed directly from decaying matter

What did Varro believe in 120 BC?

Diseases were caused by small animal, too small to be seen and are carried in the air

Eukaryotes

Distinguished by their membrane bound nucleus, their DNA is consistently associated with chromosomal proteins and have a number of membrane enclosed organelles

Electron type of lens

Electromagnet

The MS and C rings

Embedded in the cytoplasmic membraen

What are the two important functions of glycocalyx?

Enables certain bacteria to resist phagocytic engulfment by white blood cells in the body or protozoans in soil and water. It also enables some bacteria to adhere to environmental surfaces which will lead to colonization of that surface

What is typically more difficult for phagocytic cells of the immune system to recognize and destroy?

Encapsulated pathogenic bacteria

Exoenzymes

Enzymes produces within the cell, then released outside the cell to begin the process of extracellular digestion

Pasteur Institute

Established by the French government as a major biomedical research center focused on antiserum and vaccine research

Divide by mitosis

Eukaryotes

Has histones

Eukaryotes

Has organelles

Eukaryotes

Sterols and carbohydrates that serve as receptors present in plasma membrane

Eukaryotes

True uncles, with nuclear membrane/envelope, nuceoli

Eukaryotes

What cells are generally larger, prokaryotes or eukaryotes?

Eukaryotes

What has paired chromosomes, in nuclear membrane?

Eukaryotes

Caseinase

Exoenzyme that hydrolyzes the milk protein casein

Since most cells are clear, what is used to bring up the contrast?

False coloring

Pseudopods

False feet

Who suggested the use of agar?

Fannie Wilshemius who was the wife of one of Koch's assistants

What did Fannie's agar provide?

Fannie suggested the use of agar as a solidifying agent, providing a level inert surface material for microbes to grow on, other nutrients (salts, sugars, proteins) could be included to satisfy the microbes nutritional needs

What are non polar tails made of

Fatty acids that are hydrophobic and insoluble in water

Examples of trace elements

Fe, Cu, Mo, Zn, B Co, Mn

What are the three parts of the flagellum

Filament, hook, basal body

What was Leeuwenhoek able to first view what with the simple microscope?

First single-celled organisms (animalcules)

There are a few advantages to the growth pattern of biofilms:

First, bacteria are protected from the inhibitory effects of antimicrobial compounds, biocides, chemical stresses (such as pH and oxygen), and physical stresses (like pressure, heat, and freezing). Second, the polymeric matrix increases the binding of water and leads to a decreased chance of dehydration of the bacterial cells—a stress that planktonic cells are subject to. And third, close proximity of the microorganisms in biofilms allows nutrients, metabolites, and genetic material to be readily exchanged.

Amphitrichous

Flagella on both poles of cell

What did Francesco Reid suspect?

Flies landing on the meat laid eggs that eventually grew into maggots

Where is algae most abundant?

Fresh and salt water, and in soil

Flies proteins

Function as the motor swtich

What does Gram staining look at

Fundamental differences in the cell wall of bacteria

Examples of eukaryotes

Fungi, protozoa and algae

Small scale cultivation on plates is done in

GasPak jars

Ways to grow bacteria

Generally you start off with either a solid or liquid culture, then the size of the culture you want, next figure out the nutritional requirements and make the media. Then you grow it in the right environment: in a incubator for solid (plate cultures) and standing liquid culture (bottle/flask).

Robert Koch provided definitive proof of what

Germ Theory of Disease

Scanning electron microscope (SEM)

Gives highly magnified, 3-d images of the specimen

Light type of lens

Glass

Limited LPS

Gram-positive

Thick peptidoglycan

Gram-positive

Tetrad

Group of four spheres

Phase contrast microscopes

Have a phase plate which filters out the original image components. The resultant image is the samples effect on light

How did Jenner confirm his cowpox theory?

He deliberately infected patients with matter from cowpox lesions. In May 1796, Jenner found a young dairyman, Sarah Nelms, who had fresh cowpox lesions on her had and arms. On May 14, 1976, using matter from Nelms' lesions, he inoculated an 8-year-old boy, James Phipps. Subsequently, he felt cold and had lost his appetitive, but on the next day hw was much better. In July 1796, he inoculated the boy again, this time with matter from fresh small pox lesions. No disease was developed, and Jenner concluded that protection was complete.

Lazzaro Spallanzani's experimental design

He repeated the experiments of Needham, but removed air from the flask, suspecting that the air was providing a source of contamination. Nutrient broth was placed in flask, heated, air removed, then sealed. No growth was observed

Redi experimental design

He used three pieces of meat. Once piece of meat was left in the open jar, resulting in maggots and flies. One piece of meat was left in a sealed jar, no maggots or flies could be observed as the meat decomposed. In the final test, a third piece of meat was overlaid with cheesecloth which allows air to go in, but not access for flies. Flies and maggots were observed on the surface of the cheesecloth but not inside the jar where meat was.

Spirochetes

Helical and flexible spirals. They have axial filaments, which resemble flagella but are contained within a flexible external sheath

Spirillum

Helical shape like a corkscrew, and are rigid, spirilla move using flagella

Electron medium of travel

High vacuum

Pasteur's experimental design

His experiment consisted of filling several short necked flasks with nutrient broth and then boiled the contents. Some were left open and allowed t cool, in a few days, these flanked were contaminated with microbes. The other flasks, sealed after boiling were free of microbes.

Robert Koch was an important microbiologist because

His pioneering work in the isolation and characterization of bacterial diseases helped to identify the causes of many of the maladies plaguing humanity

What did Needham's experiment support?

His results supported spontaneous generation.

Nosepiece

Holds the objective lenses, rotates

Penicillian was called a "miracle drug" because it doesn't harm human cells. Why doesn't it?

Human cells don't contain a cell wall

Why does Azithromycin not affect humans?

Humans do not have a 50S ribosomal subunit

How did this Y. Pestis get to Europe?

Hunters trapped Marmots for their fur and transported Tham along the Silk Road. Fleas that lived on them became the vector. The Black Death was believed to have started in China, travelled along the Silk Road and Reached the Crimea by 1346. From there, the fleas came in contact with black rates which were regular passengers on merchant ships, and it spread throughout the Mediterranean and Europe

What did Needham theorize?

If he took a nutrient broth and heat it, all living things in it would die and then he could observe if microbes were spontaneously going to arise after all for hem have been killed by the heat, or would none of them be able to come back.

What did Pasteur conclude from the gun cotton filters?

If these bacteria were present in the air then they would likely land on and contaminate any material exposed to it

BSL1:

If you work in a lab that is designated a BSL-1, the microbes there are not known to consistently cause disease in healthy adults and present minimal potential hazard to laboratorians and the environment. Work can be done on an open lab bench, requires a sink. Requires personal protective equipment (PPE) such as lab coats, gloves, eye protection.

Describe Pasteur's work with Joseph Meister

In 1885, a young boy, Joseph Meister, had been bitten by a rabid dog, and was brought to Pasteur. The boy almost certainly would have died an agonizing death if nothing was done so Pasteur took the risk on using his untested vaccine. The boy survived and Pasteur knew that he found a vaccine for rabies. Three months later, when he examined Meister again, Pasteur reported that the boy was in good health.

Cell envelope

In a prokaryotic cell, the portion composed of the plasma membrane, the cell wall, and the glycocalyx.

Conjugation

In bacteria, the direct transfer of DNA between two cells that are temporarily joined.

Describe how to properly stain using simple staining

In order to fix the cells to the slide before staining, use air drying and heat fixing. The organisms are heat fixed by passing an air-dried smear of the organism thought he flame as a gas burner or a slide warmer. The heat coagulates the organism's proteins causing the bacteria to stick to the slide. When you heat fix the slide, you want to apply enough heat to precipitate the proteins to allow the cells to stick to the slide y not to drastically change the shape of the cell. Once you fix the cells, you can now flood the slide with your stain, rinse well, and pat dry with paper.

Why do microorganisms move?

In response to a stimulus which could be food, nutrients (carbon or nitrogen), to flee a predator or catching prey

Where does H. pylori live?

In the interface between the surface of gastric epithelial cells (lining of the stomach) where it often clusters are the junction of epithelial cells

Where do most microbes obtain almost all of their nutrients from?

In the solution from the surrounding aqueous environment

Describe Pasteur's Chicken Cholera Vaccine experiment

In the summer of 1880, Pasteur found a vaccine by chance. Charles Chamberland had inoculated some chicken with chicken cholera germs from an old culture that had been around for some time. The chickens did not die. Pasteur asked Chamberland to repeat wheat he had done with a fresh culture of chicken cholera germs. Pasteur reasons that a new culture would provide more potent germs. Two groups of chickens were inoculated; one that had been given old culture and one that had not. This chickens that had been given the old culture survived, those that had not died. The chickens that had been inoculated with the old culture had become immune to chicken cholera

How does Azithromycin work?

It binds to the 50S subunit of the bacterial ribosome and thus inhibits translation of mRNA. Nucleic acid synthesis is not affected. It sits in the tunnel where it would occlude the nascent polypeptide chain from transiting through the subunit.

What was the aftermath of the Plague?

It created a series of religious, social and economic upheavals which had profound effects on the course of European history. It marked the end of the middle ages and the advent of the modern world. It created a society where there was much less competition ofr food, shelter, work, even at the lower levels of the social scale. People were able to prosper like never before.

Why was the spontaneous generation idea attractive

It meshed nicely with the prevailing religious vies of how God created the universe. There was a strong bias to legitimize the idea because the vital force was considered a strong proof of God's presence in the world

Growing microbes aerobically

It's pretty straightforward-you make the culture media with the required chemical elements, use agar if you want a solid medium or skip it for a broth/liquid medium. Sterilize the medium. Inoculate the medium, put it into the incubator or shaker and wait till it grows.

Beef extract function

Its function is to complement the nutritive properties of peptone by contributing minerals, phosphates, energy sources, and essential factors missing from peptone.

What was developed from the Germ Theory of Disease?

Koch's postulates

Mycoplasmas

Lacks cell wall and sterols are found in plasma membrane

Who discovered and observed the first bacteria, sperm cell, blood cells and microscopic nematodes and rotifers and much more?

Leeuwenhoek

Leeuwenhoek's microscope used what type of microscopy?

Light

LPS is composed of what

Lipid A, Core polysaccharide and Variable O-polysaccharide

What the 2 classes of teichoic acids?

Lipoteichoic acids and wall teichoic acid

Planktonic

Live within the water column of lakes and oceans

P ring

Located in the peptidoglycan

Who finally resolved the spontaneous generation vs. biogenesis debate?

Lous Pasteur

Examples of attenuated vaccines used in humans

MMR, Polio, Influenza, BCG for TB, Typhoid , Typhus

Endospores special stain

Malachite green

Microbes are an integral part of what ecosystem?

Marine and freshwater where they are producers in the ecosystem by photosynthesis and form the basis of the food chain

Who developed the TEM?

Max Knoll and Ernest Ruska in Germany in 1931

What did Redi conclude?

Meat could not be transformed into flies, only flies can make more flies, and proposed that the theory of Spontaneous generation could not be supported and was incorrect

What are the three main groups of archaea?

Methanogens, extreme halophiles and hyperthermophiles

Plate cultures

Microbes grow the surface of an agar plate

What did Pasteur conclude from his initial experiment?

Microbes in the air were the agents responsible for contaminating non-living matter

What did Needham claim?

Microbes spontaneously developed from his fluids.

The plasma membrane is also the site of energy conservation

Microbial energy generating processes involve the generation of a proton motive form (PMF) where proteins (H+) are selectively moved across the membrane

What is the most typical fungi?

Molds

How did wine producers believe wine was produced?

Most wine producers thought wine was completely abiotic chemical process, where you tossed some grapes together, waited a bit and then the sugars in the grapes were converted to alcohol thought a simple chemical process.

Aerotaxis

Move in response to oxygen concentration

Stage

Moveable platform on which slides are mounted for viewing;

Chemotaxis

Movement in response to chemicals. Process by which can organism migrate toward nutrient sand favorable environments and away from toxins and unfavorable environments.

Example of large multicellular fungi

Mushroom

The peptidoglycan polymer is made of what two sugars?

N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)

What did Spallanzani conclude?

Needham was wrong about spontaneous generation

Can large molecules such as proteins pass through the plasma membrane?

No

What are the exceptions to Koch's Postulates

Not always possible to obtain a disease causing microbe in pure culture (not culturable, biofilms), If humans are sole host, can't ethically test the postulates (HIV), Animal models are not always available, some microbes can be isolated from both healthy and sick individuals (cholera), Some viruses do not cause illness in all infected individuals (polio)

What is the core of a virus particle made of?

Nucleic acids which is surrounded by a protein coat

What do microorganisms need in order to grow and reproduce?

Nutrients, a source of energy and certain environmental conditions

Total magnification =

Objective lens X Ocular lens

Fimbriae location

Occur at the poles or can be even distributed over the entire surface of the cell

What did Hook use to provide light to his microscope?

Oil lamp

Genome

One complete copy of the genetic information in an organism

What were the two lenses in Robert Hooke's microscope

One lens was the eye piece while the other at the bottom was the objective lens

Vector

Organism that transmits the disease

Where is the cell well located in prokaryotes

Outside the cell membrane and provides these cells with structural support and protection and also acts a a filtering mechanism

Yeast

Oval shaped microbes that are larger than bacteria

Scanning Electron Microscope (SEM)

Overcomes the sectioning/slicing problem associated with the TEM and produces a 3D-image surface of the specimen. It involves "scanning" the beam of electrons across the sample

The most well known types of shellfish poisoning?

Paralytic shellfish poisoning, neurotoxic shellfish poisoning and amnestic shellfish poisoning

Describe Pasteur's rabies vaccine experiment

Pasteur injected "clean" animals with the rabies virus found in spinal cord that was fourteen days old. At this age, the virus was relatively weak and unlikely to threaten the life of the animals. He then used spinal cords that were thirteen days old, twelve days old etc on the animals until thy were injected with the most virulent virus found in infected spinal cords that was fresh. All survived this.

Pasteur's second experimental design

Pasteur next placed broth in open-ended long necked flasks and bent the necks into S-shaped curves called Swan flask. The broth in thee flanked were boiled and cooled. The broth in the flasks showed no sign of microbial life, even after months.

Germ Theory of Disease

Pasteur suggestion that microbes cause diesase

What is the name of the heating process used by Pasteur?

Pasteurization

The Black Death/Plague/Bubonic plague

Peaked in Europe between 1348 and 1350 and killed 30-60% of Europe

What is the 50S subunit involved in?

Peptide bond formation through peptide ttanderase activity. In addition, GTP binding proteins can interact with the subunit to aid in translation processes such as initiation, elongation and termination

Why is it advantageous for cells to be able to store phosphate as polyphosphate for future use?

Phosphate is often a limiting nutrient

Algae

Photosynthetic with a wide range of shapes and sizes

Typically no organelles

Porkaryotes

The dyes are usually what charge?

Positively charged or cationic

Chromosomal DNA arrangement usually a single circular chromosome, some have linear chromosomes, lack histones except for Archaea with histone-like proteins, plasmids

Prokaryotes

Divides using binary fission

Prokaryotes

No meiosis; transfer of DNA fragments only

Prokaryotes

What typically has one circular chromosome, not in a membrane?

Prokaryotes

What are the two groups that all living cells can be classified into based on their structural and functional characteristics?

Prokaryotes and Eukaryotes

How does the "proton turbine" work

Protons, flwoing through the MOT proteins may exert forces on charges present on the C and MS rings, thereby spinning the rotor and the attached filament. It can rotate at around 20,000 rpm with an energy consumption of only around 10-16 W

What do protozoa use to move?

Pseudopods, flagella or cilia

four broad classes of microbes in relation to their growth temperature optima:

Psychrophiles, mesophiles, thermophiles, hyperthermophiles

Gram-positive

Purple-blue staining

Gram-negative

Reddish-pink staining

Macronutrients

Required in large amounts by the cell

Immunity

Resistance to disease

What is the limiting factor in our ability to see small objects?

Resolution

Larger ribosomes (80s)

Ribosomes

Who was the first to build elaborate compound microscopes?

Robert Hooke

What is the shape, diameter and length of E. coli cells?

Rod shaped; 0.8 micrometers; 1-2 micrometers long

Bacillus

Rod-shaped

If you are only interested in the external features of an organism, what should you use?

SEM

What is smaller SEM or TEM?

SEM

What are the three types of stains:

Simple, differential and special

Another time when you will need enrichment cultures

Since microbes may be present in small numbers can be missed, especially if other microbes are present in much larger numbers, like for soil or fecal samples. The medium for an enrichment culture provides nutrients and environmental conditions that favor the growth of a particular microbe but not others.

Electron transparency

Sliced thin enough for electrons to pass through

During much of human history, infectious diseases dominated, one of the deadliest scourges to human kind was

Smallpox

How are polyphosphate granules used

Some and be degrade and used as source of phosphate for nucleic acids and phospholipid biosynthesis and in some organisms can be used to directly make ATP

extreme halophile

Some halophiles are capable of growth in very salty environments, typically 15-30% for optimum growth, and they cannot grow at all if the concentration is below this

Differential stains

Stains one kind of cell nut not another, helping to separate them into groups by utilizing different properties of the cell in order to distinguish them

Gram-negative bacteria

Stains red/pink and tend to be more resistant to antibiotics, but some types such as chloramphenicol and streptomycin might work.

Bacteria can also be what shape?

Star shape or square

Stells

Star shaped

The Golden Ages of Microbiology

Started roughly in the mid-1850s to the early 1910s. During this period, rapid advance lead to the establishment of Microbiology as a science

What do the teichoic acids provide?

Structural support, stabilizing the cell wall and making it stronger. It may also help in maintaining a negative charge of the cell wall and in ion transport

Most bacterial species are motile and move by

Swimming through liquid environments or by moving across surfaces

Maximum =

Temperature above which no growth occurs

Optimum =

Temperature at which the bacterium grows most rapidly

Minimum =

Temperature below which no growth occurs

Physical requirements for growth

Temperature, pH and Osmotic pressure

Fimbriae function

Tendency to adhere to each other and to surface, as a result, they are involved in forming biofilms. They can also help bacteria to adhere to epithelial surface in the body which helps the pathogen colonize the host and establish infection

neutrophils

Terms used to describe organisms that grow best at a neutral range (pH >5.5 and <8). The approximate pH for optimal growth is 7

What happens at the origin of bacterial chromosomes?

The DNA double helix is melted open by binding proteins, and then DNA polymerase synthesizes new strands in both directions which is known as theta replication

Koch's success depended on the technical achievements of what?

The Petri dish, agar and culture media

Resolution

The ability to distinguish two adjacent objects as separate and distinct

What did proponents of spontaneous generation discount about Spallanzani's experiment?

The air was required for the vital force to work

What did Pasteur conclude?

The chicken's bodies had used the weaker strain of germ to form a defense against the more powerful germs in the fresher culture. he found that the bacterium that causes chicken cholera lost its ability to cause disease.

The darker areas of an image produced by TEM represents

The dense areas of the object

What did Needham notice about his broth?

The development of a thick turbid solution of microorganisms (and thus microbial growth) in the flask

Iris Diaphragm

The diaphragm is located just below the stage and controls the amount of light which passes to the specimens and can drastically affect the focus of the image

Contrast

The difference in visual properties that makes an object distinguishable from other objects and the background. You will get a better image

Carboxysomes are inclusions that contain

The enzyme Ribulose 1,5 dispute carboxylase for carbon dioxide fixation

Chemically defined media

The exact composition of pure chemicals used to formulate the media is known

Yeast extract

The extract of yeast cells provides vitamins and other organic growth factors, they also supplement the organic Nitrogen and carbon compounds.

What is the first name?

The genus and is always capitalized and italicized

Spontaneous generation

The hypothesis that living organisms arise spontaneously from nonliving matter. It requires a "vital force," (present in air) to form life

Biogenesis

The hypothesis that the living organisms arise from preexisting life

This domain classification replaces the last highest classification of all living things

The kingdom

Lipid A

The lipid portion of LPS which acts as an anchor for the molecules into the cell membrane

Substances that dissolve easily in lipids enter and exit more easily than others because

The membrane consists of mostly phospholipids

Batch cultures

The more common is the batch culture where microbes are cultured in an enclosed vessel (tube, flask) with a broth medium that supplies its nutritional requirements. Microbes are inoculated into this medium and placed in an appropriate environmental condition. Microbes will adjust and grow in this medium until nutrients run out, and/or toxic waste products are accumulated, and there are too many cells-running out of space (physical limitation), and growth ceases.

What did Richard Petri invent?

The petri dish

What did Pasteur's work with wine reveal?

The process of converting sugar to alcohol is actually performed by various yeast strains. He then showed that the wine was going bad because a contaminating bacterial microbe was generating lactic acids instead of alcohol from sugar.

Magnetotaxis

The process of migrating along Earth's magnetic field lines

Why did Hooke call them cells?

The shape of the hollow cell walls in a slice of Cork reminded home of the shape of monks' cells in a monastery

What is the second name?

The specific epithet (species name) which is not capitalized and is italicized

Phylogenetic

The study of evolutionary relationships based on the ribosomal RNA (or other gene or protein)

What is microbiology?

The study of microbes

Koch's second postulate

The suspected pathogen must be grown in pure culture

Koch's fourth postulate

The suspected pathogen must be preisolated and shown to be the same as the original

The cell wall

The tough, usually flexible but sometime a fairly rising layer that surrounds some type of cells

What was discovered during the Golden Ages if Microbiology?

The true nature of infectious disease, the role of immunity in preventing and curing disease, people started studying the chemical role of microbes, the techniques for microscopy, culturing, vaccine development and improving surgical techniques

What did Pasteur's team know about the rabies virus?

The virus attacked the nervous system only after it had made its way to the brain.

Humans, animals and even insects depend of microbes in what locations?

Their intestines for digestion and synthesis of some vitamins

What did Edward Jenner notice about Milkmaids in the late 1700s.

There were protected from smallpox after they contracted cowpox, a related. ut much milder disease

What makes viruses a very different microbe?

They are not cellular, and are structurally very simple.

What makes archaea different from bacteria?

They did not have peptidoglycan in their cell walls

A few prokaryotes are pleomorphic meaning

They have the ability to alter their shape or size in response to environmental conditions

What common thread did Pasteur seem to find between wine and infectious diseases?

They might both involve infection by a microorganism

anaerobic chambers (also called a glove box)

This is usually a plastic chamber that contains an atmosphere of H2, CO2, and N2. Culture media are placed within the chamber by means of an airlock which can be evacuated and refilled with N2. From the airlock ,the media are placed within the main chamber where the work or cultivation is to be done. Any oxygen in the media is slowly removed by reaction with H2, forming water; there is also a palladium catalyst in here to aid the process. After being rendered oxygen free, the media are inoculated within the chamber (by means of the glove ports) and incubated (also within the chamber).

What is a disadvantage of using complex media

This nutritional composition is now precisely known

What is a major function of the cell well

To act as a pressure vessel, preventing over-expansion when water enters the cells

What did Robert Koch need to test the idea that microbes caused some diseases?

To isolate the causative agent

How did the team trace the rabies virus

To the brain and spinal cord of infected animals and by using dried spinal cord, they produced the vaccine for rabies

If aerobes are plain this an environment with air bubbles, where will they move

Towards the air bubbles

The consumption of undercooked pork could lead to

Trichinosis

Pili are involved in a special type of motility known as

Twitching motility

Protozoa

Unicellular microbes

Slime layer glycocalyx appearance

Unorganized and more loosely attached

Light microscopy

Use of any kind of microscope that uses visible light to observe specimens

Simple staining

Use one basic dye and its purpose is to highlight the entire organisms so that cellular shapes and basic structures are visible

For nutrition, what do most bacteria do?

Use organic compounds, some make their own food via photosynthesis and some get it from inorganic substances?

Special stains

Used to color and isolate specific parts of microbes, such as the endospores, flagella or to reveal the presence of capsules

Darkfield illumination

Uses a dark field condenser that contains an opaque disk, which is often used to examine unstained live specimen

Objective lenses

Usually 2-4 lenses with magnification of 4x, 10x, 40x, 100x oil immersion.

Light source

Usually a bright halogen bulb. The rheostat switch is used to regulate light intensity

Ocular lens or eyepiece

Usually at 10x magnification.

The practice of cowpox inoculations called

Vaccination

Who was the first to observe single celled microbes called "animalcules"

Van Leeuwenhoek

Who won the Nobel prize in chemistry in 2009 for showing what the ribosome looked like and how it functioned at the atomic level?

Venkatraman Ramakrishnan, Thomas A Steitz, Ada E. Yonath

What is important in the containment and control of infectious diseases?

Vigilance, research and public information

Transmission Electron Microscope (TEM)

Was the first type of electron microscope to be developed and is pattered exactly on the light microscope except that a focused beam of electron is used instead of light to "see through" the specimen.

When does it mean to be not culturable?

We don't know their nutritional requirements, some exist in communities attached to each other and a surface, like a biofilm, which are complicated ecosystems that may not be replicated in the lab. Many of these microbes can't live without other microbes.

Attenuated

When strains of bacteria or viruses lose its ability to cause serious disease in the host organism

Eukaryotes do what with their DNA

Wrap their DNA around proteins called histones to help package the DNA into smaller spaces

What pathogen is responsible for the Black Death?

Yersinia Pestis

A practical advantage to the chemostat is that

a cell population can be maintained in the exponential growth phase (where cells are rapidly dividing) for long periods, days or even weeks.

Agar

a complex polysaccharide polymer derived from marine algae. It isn't broken down by bacteria, unlike previously used gelatin or starch polymers. It provides an ideal solidifying medium platform.

MacConkey agar

a culture medium designed to grow Gram-negative bacteria and stain them for lactose fermentation. Selectivity of the medium is due to the presence of crystal violet and bile salts, which will both inhibit the growth of Gram-positive bacteria Differential action is based on lactose fermentation, which produces acid end products that causes the neutral red dye in this medium to turn red.

In prokaryotic cells, DNA is present in

a large double stranded molecule called the chromosome. It aggregates within the cell to Norma. mass called the nuceloid

The mycelia acid of acid-fast cells forms

a layer outside of a thin layer of peptidoglycan, which are help together by a polysaccharide

Biofilms usually consist of

a mixed bacterial population, but they may also consist of a single bacterial species

The major structures in the cytoplasm of prokaryotes are

a nucleoid (containing DNA), ribosomes, and reserve deposits called inclusion bodies

What is the polar head made of

a phosphate group and glycerol that is hydrophilic and soluble in water

Each phosophlipid bilayer contains

a polar head and non polar tails

A pure culture is defined as

a population containing only a single species or strain of bacteria. A culture is considered a pure culture if only one type of organism is present

What does the 5S rRNA molecule appear to act as

a seventh domain in the large ribosomal subunit in conferring stability to the entire 3D structure

To improve the resolving power,

a shorter wavelength is needed

Bacillus shaped

a single rod

The nucleoid of a bacterial cell usually contains

a single, long, continuous and frequently circularly arranged thread of double stranded DNA which is the cell's genetic material

In the streak plate method

a small amount of inoculum is picked up on a sterile inoculating loop, made of wire (easily sterilized by heating).The loop is drawn repeatedly across the surface of the plate, diluting microbes as it moves.

Lipopolysaccharide (LPS) is

a substance present in the outer membrane of gram-negative bacteria and penetrates into the surround environemtn

Glycocalyx

a sugary coat which is secreted by most Bactria. An outer viscous covering of fibers extending from the bacterium that is outside of the cell wall

The bacteria that become part of a biofilm engage in quorum sensing

a type of decision-making process in which behavior is coordinated through a "chemical vocabulary."

Gram staning is based on the

ability of the bacterial cell wall to retain a certain dye during solvent treatment

Nitrogen is

about 13% by dry weight of the cell and a key element in proteins, nucleic acids and other call parts

Light medium of travel

air

Acid-fast staining is used by microbiologist to identify

all bacteria in the genus Mycobacterium. This stain is also used to identify some pathogenic stains from the genus Nocardia

The optimum temperature reflects a state in which

all or most cellular components are functioning at their maximum rate and is usually closer to the temperature maximum than to the minimum.

What is included in the bacteria domain?

all pathogenic prokaryotes, many non-pathogenic prokaryotes found in soil and water and photoautotrophic prokaryotes

What are the three main types of growth factors

amino acids for proteins, purines/pyrimidines for nucleic acids and vitamins (mainly B-type vitamins)

Amylase

an exoenzyme the hydrolyzes stash into mono and disaccharide subunits

In gram-negative bacteria the peptidoglycan is surrounded by

an outer membrane on one side and by another inner cell/plasma membrane facing the inside of the cell.

Larger cultivation and processes are done in

anaerobic chambers (also called a glove box)

Basal. body

anchors the flagellum to the cell wall and plasma membrane

The rabies vaccine was the first vaccine tried on

animals

What is included in the eukarya domain?

animals, plants, protozoans, protists, and fungi

The gram-negative outer membrane which contains LPS, an endotoxin can block hydrophobic components such as

antibiotics, dyes and detergents protecting the sensitive inner membrane and cell wall

In between the origin and the terminus, the chromosome is condensed into

approximately 500 loops

If the pH is raised to 7, the cytoplasmic membrane of acidophiles

are destroyed and cells lyse.

Many microphiles are also capnophiles,

as they require an elevated concentration of carbon dioxide too.

What were the 3 processes philosophers believed living things arose from

asexual reproduction, sexual reproduction and from nonliving matter

Autotrophs

assimilate inorganic CO2 as a carbon source, reducing it (adding hydrogen atoms) to make complex cell constituents made of C, H and O.

Research over the last decade has shown that ____ also possess protein cytoskeleton components and remarkably, some of them are homologous to wukaryotic proteins such as tubular and actin

bacteria

Aerobes

bacteria that utilizes oxygen

Why was penicillin called a "miracle drug"

because it doesn't harm human cells

Why does acid-fast bacteria retain the red/pink cabolsuchsin stain

because it is more soluble in the waxy cell lipids in the acid alcohol mixture

Without a strong cell wall, the bacterium would

best from the osmotic pressure of the water flowing into the cells

The pathogenesis of gram-negative cells contributes to the ability to

bind to surfaces

Many microorganisms can satisfy their own requirements for growth factors through

biosynthetic processes (making their own) but some require one or more preformed from the environment and must then by supplied in the media culture in lab

The only difference between liquid (or broth) media and agar media is that

broths do not contain the agar component

Endospores can be dormant for thousands of years and may return to its vegetative state by a specialized process

called germination when conditions are improved for the cell.

Molecular oxygen (O2) is not toxic, but O2

can be converted to highly reactive toxic oxygen by-products

Facultative anaerobes (or facultative aerobes or just "facultative") are organisms that

can switch between aerobic and anaerobic types of metabolism. Under anaerobic conditions (no O2) they grow by fermentation or anaerobic respiration, but in the presence of O2 they switch to aerobic respiration.

halotolerant microbes

can tolerate some level of dissolved solutes, but grow best in the absence of added solute or very limiting quantities.

Molecules that carry a fixed charged

cannot cross the phospholipid bilayer

Aerotolerant anaerobes

cannot use oxygen for growth, but they tolerate it well. These bacteria use an exclusively anaerobic (fermentative) type of metabolism, whether or not O2 is present in their environment

In gram-positive cells, NAG and NAM serve as

carbohydrate "backbone" and cross linking them re tetra peptides (4 amino acids)

About half the dry weight of a typical cell is made of

carbon

Hydrogen and oxygen is usually attached to

carbon

The key macronutrients are

carbon and nitrogen

Under certain conditions, however, plasmids are at an advantage and can

carry gens for antibiotic resistance, tolerance to heavy toxic metals, produce toxins, synthesize specialized enzymes for the degradation of unique compounds and under in transferring genetic material between cells

Some of the membrane proteins

catalyze bioenergetic reactions, transport substances, detect environmental signs and secrete communication signals

The chromosome of prokaryotes is attached to the

cell membrane

The gram-negative cell envelope includes the

cell wall and the cell membrane compoents

Most cells appear colorless when viewed through a standard light microscope because

cells are mostly made of water

What is included in the archaea domain?

cells which do not have peptidoglycan in cell walls, live in extreme environments and carry out unusual metabolic processes

The plasma membrane have selective permeability indicating

certain molecules and ions pass through the membrane, while others are preventing. This allows the cell the to concentrate certain metabolites and excrete waste materials

Most vitamins functions as

coenzymes which are nonprotein components of enzymes

Vibrios

comma-shaped

The gas vesicles are

conical shaped structures made of protein; they are hollow yet rigid

Staining is what improves the

contrast between the specimens and the background of the slide

The polymer id further strengthen by

covalent bonds between cross-bridges and the degrees of cross-linking determines the degree of ridigity

Vacca

cow

Culturing

cultivating bacteria in a microbiology laboratory environment, and culture media contain the nutrients and other substances required to cultivate bacteria

A nutrient material prepared for the growth of microbes in a lab

culture media

Images produced with bright field illumination appear

dark and/or highly colored against a bright, often light gray or white background.

The 30S subunit has a crucial role in

decoding mRNA by providing the A, P and E binding sites and being responsible for monitoring base-pairing between he codon on mRNA and the anticodon on tRNA

Most microbes get nitrogen from

decomposing protein containing material and re-incorpoartion the amino acids into new proteins. Some use NH4+, some get nitrogen from nitrates in solution, while some photosynthetic cyanobacteria use N2 gas through nitrogen fixation

Peptones

derived from animal, milk, or meat digested by proteolytic digestion. In addition to containing small peptides, the resulting dried material includes fats, metals, salts, vitamins and many other biological compounds.

Obligate anaerobes (occasionally called aerophobes)

do not need or use O2 as a nutrient. In fact, O2 is a toxic substance, which either kills or inhibits their growth.

facultative halophiles

do not require high NaCl concentrations but are able to grow at salt concentrations up to 2%, a concentration that inhibits the growth of many other organisms

Both 40S and 60S subunits contain

dozens of ribosomal proteins arranged on a scaffold composed of ribosomal RNA, the 5S, 18S and 28S

Generally, you prepare reducing media for anaerobic cultures

during preparation of the culture media, it is boiled for several minutes to drive off most of the dissolved oxygen. A reducing agent, such as cysteine, is added to further lower the oxygen content, and oxygen free N2 is bubbled through the medium to keep it anaerobic. Then medium is then dispensed into tubes, again, flushed with N2, stoppered and then autoclaved.

Evidence indicates that all cells, organelles such as mitochondria and chloroplasts, and all major metabolic pathways evolved from

early prokaryotic cells

Sulfur is obtained from

either sulfur containing amino acid or from sulfate and sulfude

Electron radiation source

electron beam

Viruses can only be seen by what type of microscope?

electron microscope

The oxidation of sulfide is linked to the need for

electrons to drive either reactions of energy metabolism or carbon fixations

L ring

embedded in the outer membrane and LPS

Infectious diseases are not disappearing, but rather

emerging or reemerging

One example of an extreme survival strategy employed by certain Gram-positive bacteria (mostly in the Clostridium and Bacilllus genera) is the formation

endospores which is often initiated in response to nutrient deprivation

Many cells perform active transport whereby the cell uses

energy in the form of ATP in order to move substances across the plasma membrane

Sulfur granulates serve as

energy reserves

selective and differential characteristics are combined in a single medium

enhance the growth of certain species that can then be distinguished by other species due to variations in their effect on the medium or by the color of colonies they produce.

Chocolate agar

enriched with heat-treated blood (40- 45°C), which turns brown and gives the medium the color for which it is named.

Lipases

enzymes that break down lipids, which can be directly observed by changes in the appearance of a lipid structure

Often though, two or more cells are in a clump, they will grow to form only a single colony. So if a sample contains many cell clumps, a viable count (viable means one that successfully replicates to form a colony) of that sample may be

erroneously low

Microbes produces industrial chemicals such as

ethanol and acetone

Chromosomal (DNA) arragnement is multiple linear chromosomes; histones

eukaryotes

Cytoskeleton; cytoplasmic streaming in cytoplasm

eukaryotes

Meiosis

eukaryotes

Membrane associated organelles present

eukaryotes

All three Nobel laureates hade generated structures showing

exactly where different antibiotic attack bacterial ribosomes

Electron microscopes were developed to

examine structures too small to be resolved with a light microscope such as ribosomes, but can also give gene detail for large structures such as a red blood cell

O-polysaccharide

extend outward from the core polysaccharide and is made of sugar molecules. It functions and an antigen

Plasmids are

extra-chromosomal genetic elements that are not connected to the main bacterial chromosomes and replicate independent of the chromosomal DNA

Chemotaxis occurs in many species of bacteria when

extracellular signals are detected by transmembrane receptors and relayed to flagellar motors

Where are archaea usually found?

extreme environments, very hot, very cold, very salty, low/high pH

Obligate anaerobic prokaryotes may live by

fermentation, anaerobic respiration, bacterial photosynthesis, or the novel process of methanogenesis.

Without resolution, no matter how much the image is magnified, the amount is observable detail is

fixed

Peritrichous

flagella distributed all over the cell

In a prokaryotic cell, the term cytoplasm refers to the

fluid-like substance inside the cell membrane. It represent nearly 70% of the wet weight of the cell. It is about 80% water and contains primarily proteins (enzymes) carbohydrates, lipids, inorganic ions, ions, dissolved gases.

Chemostat in microbial ecology

for enrichment and isolation of bacteria for nature by selecting for a stable population under nutrient and dilution rate conditions chosen

Superoxide free radicals or superoxide anions, are

formed in small amounts during normal respiration of microbes that use oxygen as the final electron acceptor. These radicals are toxic to cellular components.

The proteins move to

function

MOT proteins

function as the flagellar motor

Water availability is not only dependent on how moist or dry an environment is, but also a

function of the concentration of solutes (salts, sugars, etc.) dissolved in the water that is present.

Many planktonic organisms can float because they contain

gas vesicle which cause buoyancy which allows the cells to position themselves in a water column in a particular location

"Immersion oil"has the same refractive index as

glass

Abundant LPS

gram-negative

Excel in host intestinal environments

gram-negative

High lipid content

gram-negative

Low susceptibility to penicillin

gram-negative

No techoic acids

gram-negative

Outer membrane

gram-negative

Periplasmic space present

gram-negative

Susceptible to mechanical stress

gram-negative

Thin peptidoglycan

gram-negative

low susceptibility to lysozymes

gram-negative

The o-polysaccharide if useful in distinguishing species of

gram-negative bacetai

Abundant techoic acids

gram-positive

Better in dry conditions

gram-positive

High susceptibility lysozymes

gram-positive

Low lipid content

gram-positive

Penicillin sensitive

gram-positive

Periplasmic space absent

gram-positive

resistant to mechanical stress

gram-positive

Acidophiles

grow at pH<5.5, there are different classes of acidophiles, some grow best at moderately acidic pH (pH5) and others at very low pH (pH 1). Some acidophiles are obligate (require) acidic conditions

Its been hypothesized that one function of magnetosomes may be to

guide these primarily aquatic cells downward toward the sediment where oxygen levels are lower

Unidirectional flagella

have to stop, reorient itself in order to change direction

In Gram-positive cells the peptidoglycan is

heavily cross-linked woven structures that encircles the cell in many layers. It is very thick with peptidoglycan accounting for 50% of weight of cell and 90% of the weight of the cell wall.

The organic compounds made by autotrophs can then be used by

heterotrophs

Acidophiles are not just acid tolerant but require

high concentrations of H+ for membrane stability.

Through their anaerobic metabolism, some magnetosomes will accumulate

high concentrations toxic metal from the water

Thermophiles

high temperature optima. Certain bacteria can live and grow at temperatures that exceed 50degC

Endosporescan survive environmental assaults that would normally kill the bacterium. These stresses include

high temperature, high UV irradiation, desiccation, chemical damage and enzymatic destruction.

Brilliant Green Agar

highly selective medium used to inhibit gram-positive bacteria and most gram- negative bacilli for the selective isolation of gram negative Salmonella species from feces and other clinical specimens.

Digestive exoenzymes break down large molecules into smaller ones via

hydrolysis

mixed culture

if populations of different organisms are present (as seen here in this top plate, note the different colony types)

Confocal microscopy

illuminated each plant in a specimens to produce three-dimensional images up to 100 micrometers deeps. It uses fluorescence as well

Mangetosomes

impart a magnetic dipole on a cell, allowing it to orient itself in a magnetic field

gas vesicles are

impermeable to water and solutes, but permeable to gases.

Gas vesicles occur almost exclusively

in prokaryotes from aquatic habitats

The hydroxyl radical is another intermediate form of oxygen and probably the most reactive. It is formed

in the cytoplasm by ionizing radiation.

What physiological reactions does LPS create?

induction of fever, changes in white blood cell count, leakage from blood vessels, tumor necrosis and lowered pressure leading to vascular collapse and eventually shock. It can be lethal at high enough concentrations.

Bacterial exoenzymes are produced in the largest amount on an

industrial basis, used as additives in laundry detergents

Bacteria that break away from a biofilm can cause

infections in patients using catheters

The difference in color shade in TEM images provides

information on the structure, texture, shape and size of the sample

What are some of the outcomes of antibiotics attacking bacterial ribosomes

inhabit the monitoring mechanism of the molecular ruler, under the formation of the connection between amino acids or block the tunnel through which the merging protein chain leaves the ribosome

Coarse focus

innermost

GasPak jars

inoculated plates or tubes are placed inside the jar, and anaerobic conditions are created by adding water to a gas generator envelope placed in the jar just before sealing. The envelope contains two chemical tablets: sodium borohydride and sodium bicarbonate. Water reacts with them producing hydrogen gas and CO2. The H2 combines with free oxygen in the chamber to produce water, removing all the free oxygen from the chamber. This reaction is catalyzed by palladium, which is attached to the underside of the lid of the jar. The CO2 replaces the removed oxygen, creating a completely anaerobic environment.

Trace elements are

inorganic

Phosphorous is usually supplied to a cell as

inorganic phosphate

Sulfure originates from

inorganic sources in nature (sulfate and sulfide)

Pili fucntion

involved in DNA transform. They often play an important role in connecting two cells for the exchange of genetic material, and in the attachment to host cells during infection

Among the substances actively transported are

ions, amino acids, and simple sugars

Blood agar

is considered to be differential but not selective, because it is an enriched medium that provides a rich nutrient environment for many types of bacteria, while a selective medium supports the growth of certain types of bacteria but inhibits other types.

In gram-negative bacteria, the peptidoglycan

is much thiner with only 15-20% of the cell wall being peptiodyglycan and it is only intermittently cross-linked with tetapeptide side cahins

Phosphorous

is need for synthesis of nucleic acids and phospholipids and is also found in high energy bonds of ATP. Can occur as organic or inorganic phosphates

Complex media are often referred to as "Rich" media, which means

it contains the nutrients required to support the growth of a wide variety of organisms, including some of the more fastidious ones.

Any type of staining going to

kill cells and distort its features to some degree

BSL-4

labs builds on the containment requirements of BSL-3 and is the highest level of biological safety. BSL-4 labs is required for work with dangerous and exotic agents that pose a high individual risk of life-threatening disease, aerosol transmission or unknown risk of transmission. The microbes in BSL4 labs cause infections that are frequently fatal and generally there are no vaccines or treatments for these infections. There are only a small number of such labs in the U.S (<10) and the world. Laboratory staff must have specific and thorough training in handling extremely hazardous infectious agents. Access to the laboratory is controlled by the laboratory supervisor. All handling of agents must be performed in a gas tight Class III Biosafety Cabinet or by personnel wearing a positive pressure protective suit. BSL-4 Laboratories have special engineering and design features to prevent microorganisms from being released into the environment. The lab is in a separate building or isolated restricted zone of the building, and has a dedicated supply and exhaust air, as well as vacuum lines and decontamination systems. Personnel mush change clothing before entering and shower upon exiting.

Phospholipids rotate and move

laterally

microbes produce products uses in manufacturing food additive and many important enzymes are used in your

laundry detergent and medicine such as insulin

In this complex biofilm network, the cells act

less as individual entities and more as a collective living system, often with channels to deliver water and nutrients to the cells at the inner portion of the biofilm

These enzymes are often able to convert these toxic oxygen radicals to something less damaging,

like water.

Wall teichoic acid

linked only to the peptiodglycan layer

The outer membrane of gram-negative bacteria is another lipid bilayer similar to the cytoplasmic membrane and contains

lipids, proteins and LPS

Most move by using a flagella which are

long filamentous appendages that propel bacteria

Filament

long outermost region that is made of flagellin proteins

Stab cultures are good for

long term storage of microbes and also for figuring out motility and oxygen requirements.

Slant cultures are also suitabitl for

longer term maintenance of bacteria

The bacterial DNA is packed into

loops back and forth which concentrates the DNA of the cell, but it is not separated by a nuclear membrane.

Loss of light leads to

loss of image detail

psychrophiles

low temperature optima These are cold loving microbes that prefer a range from just below 0degC to 11degC.

Glycosidic bonds are sensitive to

lysozyme

Differential media

make it easier to distinguish colonies of the desired organism from other colonies growing on the same plate. It is a media that supports growth of many different organisms, but differentiates between them. This type of media will allow identification of microbes based on their growth, color, and appearance on the medium

There are numerous antibacterial agents that target the bacterial cell wall because

mammals do not synthesize walls and therefore are not susceptible to the toxic effects of these agents

batch cultures

meaning they are closed systems, the microbe is growing in an enclosed vessel: you put a set amount of liquid culture media in a bottle/flask/test tube and inoculate it with your microbe, there is no new media supplied during the course of growth, once they use up all the nutrients, they generally stop growing.

thioglycollate is a

medium that may be used in two ways: to grow microorganisms under anaerobic conditions, or to test for the oxygen requirements of a bacterium.

Volutin

metachromatic granulates which act as a storage form of complexed inorganic polyphosphates

Halophiles

microbes that inhabit these marine environments almost always have a NaCl requirement

Biofilms on surfaces have a characteristic structure consisting of

microcolonies enclosed in a hydrated matrix of microbially produced : proteins, nucleic acids, and polysaccharides, often called a slime or hydrogel

mesophiles

midrange temperature optima. These are the moderate-temperature loving microbes, with a range form 9 to 48degC. Neither too hot nor too cold, typically between 25 and 40°C (77 and 104 °F).

We use special oil immersion lenses to

minimize refraction

Some diseases are polymicrobial meaning

more than one pathogen is the cause, so you won't be able to get a pure culture all the time to test

Contamination means that

more than one species is present in a culture that is supposed to be pure

Microorganisms sense and adapt to changes in their environment. When favored nutrients are exhausted, some bacteria may become

motile to seek out nutrients, or they may produce enzymes to exploit alternative resources

In broth, a species may display

motility and/or a characteristic pattern of association among individual cells, such as chains or clusters, that is not obvious in agar cultures

Some bacterial with color flagella will have reversible motors that allow them to

move forward when it turns CCW and backwards when it goes CW

If you are converting to larger numbers,

move the decimal to the left or divide

To convert to smaller units,

move the decimal to the right or multiply

Phototaxis

movement in response to light

Fungi can be

multicellular or unicellular

Prokaryotes often only have a singular enclosed circular chromosome. However, some have

multiple chromosomes or even linear chromosomes

These growth factors may be needed in varying concentrations, ranging from

none to mg quantities per liter

Singlet oxygen is

normal molecular O2 that has been boosted into a higher energy state and is extremely reactive.

Special techniques, commonly referred to as aseptic pure culture techniques, must be used to

obtain a single isolated strain for study

The compound light microscope uses what two lenses to magnify the specimen image

ocular and objective

Spiral shaped

one or more twists; they are never straight

Pure culture

one species of microbe in isolation

Thus, each colony on an agar plate represents

one viable organism (or CFU) present in the original liquid culture

Growth factors are

organic and required in small amounts only by certain organisms

Microbes/microorganisms are

organisms that are too small to be seen with the unaided eye

bacterial chromosomes are arranged with a

origin of replication at one end and a terminus at the other

Fine focus

outermost

Chemoautotrophs gain energy by

oxidizing inorganic substances such as iron or ammonia

Diplobacillus

paired rods

Diplococcus

paired spheres

Peroxide anions are produced as

part of Hydrogen peroxide (H2O2).

In Mosaic Law,

people understood that there were certain foods that were to be avoided, such as pork and seafood

The 60S subunit catalyzes

peptide bond formation

Gram-positive cell walls are mainly

peptidoglycan and threading between this is teichoic acids which consists primarily of an alcohol and phosphates

The space between the outer and inner membrane where peptidoglycan is found is known as

periplasm

Usually a redox indicator dye such as resazurin is present to signal oxic (oxygen-containing regions); the dye is

pink when oxidized and colorless when reduced and thus gives you a visual assessment of the degree of penetration of O2 into the medium.

Biofilm organisms are significantly more resistant to environmental stresses or microbially deleterious substances (such as antibiotics and biocides) than

planktonic (floating or free-living) cells

What is algae associated with?

plants

Cells walls are found in

plants, bacteria, fungi, algae and some archaea

In addition to bacterial chromosomes, bacteria often contain small, usually circular double strand DNA molecules called

plasmis

Mineral ions are necessary in most microbes, elements such as iron, potassium, and sodium because they

play an important role in enzymes and macromolecules

Some bacteria use special gas vesicles which contain

pockets of gases for buoyancy and move up and down the water column

Many microbes accumulate inorganic phosphate in the form of

polyphosphate also known as volutin

One way prokaryotes compress their DNA into smaller spaces is through supercoiling which causes

portions of DNA to double back and twist itself. These interactions are stabilized by proteins

Alkaliphiles

prefer pH of 8 or above.

Azithromycin

prevents bacteria from growing by interfering with their protein synthesis

endospores allow the cell to

produce a dormant and highly resistantcelltopreservethecell'sgeneticmaterialintimesofextremestress.

Cytoskeleton proteins that are homologs to eukaryotic proteins in cytoplasm

prokaryotes

Membrane associated organelles generally absent

prokaryotes

No carbohydrates and usually lacks sterols in plasma membrane

prokaryotes

No nuclear membrane or nucleoli

prokaryotes

Smaller ribosomes (70s)

prokaryotes

Ribosomes contain both

protein and RNA molecules

Proteases hydrolyze

proteins into amino acid subunits

The plasma membrane also serves as a protein anchors which allows

proteins to anchor together in different layers of the cell envelop providing structural support

Electron microscopes

provide approximately another 1000-fold maginification over light scopes

In prokaryotes, gas vesicles function to

provide buoyancy, which allows aerophilic bacteria to float into oxygenated surface waters .

Stab (deep) cultures:

puncturing suitable medium such as nutrient agar with an inoculating needle that goes deep into the agar, allows growth within the semi-solid media.

Koch was also able to isolate bacteria in a

pure culture

In the Fluid mosaic model, phospholipids and proteins are not static but move

quite freely

Haloarcula

rectangle shape

The acid-fast stains will retain the

red/pink carbolsuchsin stain

Majority of bacteria are heterotrophs meaning they

rely on other organisms to form the organic compounds (such as glucose) that they use as carbon sources

After melting, agar

remains liquid down to 50 degrees Celsius which makes it easy to dispense, pour into containers, tubes, or dishes.

High osmotic pressures have the effect of

removing necessary water from a cell.

Obligate aerobes

require O2 for growth; and can grow at full oxygen tensions (air is 21% Ox); these microbes use O2 as a final electron acceptor in aerobic respiration.

Micronutrients

required be the cell in small amounts

BSL-3

required for work involving indigenous or exotic agents, and they can cause serious or potentially lethal disease that are transmitted through the air (via aerosols). Respiratory transmission is the inhalation route of exposure. Laboratory personnel must receive specific training in handling pathogenic and potentially lethal agents, and must be supervised by scientists competent in handling infectious agents and associated procedures. Lab personnel are under medical surveillance and might receive immunizations for microbes they work with. All procedures involving the manipulation of infectious materials must be conducted within Biosafety Cabinets (BSCs). A BSL-3 laboratory has special engineering and design features that prevent the release of microorganisms to the environment. Facilities have hands free sink, exhaust air cannot be recirculated, entrance is through two sets of self closing and clocking doors.

A microaerophile

requires oxygen to survive, but requires environments containing lower levels of oxygen than are present in the atmosphere. Therefore they need oxygen levels that are <20% concentration(which is atmospheric oxygen concentration).

What are tumbles caused by

reversal of the flagella rotation

All prokaryotes and eukaryotes contain ___ which functions as the sites of protein synthesis

ribosomes

Due to the lack of sterols in the plasma membrane, prokaryotic membranes are less ___ than eukaryotic membranes

rigid

The basal body contain a small central rod inserted into a series of

rings

coccus

round, spherical

When bacterium moves in one direction for a length of time, the movement is called a

run or a swim

Combination of rRNAs and proteins typically have a ______ than their component parts due to condensations

sedimentation rate (S)

The most important function of the plasma membrane is to

serve as a selective barrier through which material enter and exit the cells

Magnetosomes have been found in

several aquatic organisms that grow at low oxygen concentrations

Prokaryotes

single celled organisms, whose genetic material is not enclosed in a special nuclear material

The NAM, NAG and amino acid side chain from a

single peptidoglycan unit that can link with other units via covalent bonds to form repeating pikymers

Coccus shape

single sphere

The LPS of gram-negative cells lead to

some antigenic variability

Polysaccharide cell wells in

some eukaryotes - not in animal cells

Heterotrophs get most of their carbon from the

source of their energy-organic materials such as proteins, carbohydrates, and lipids. This usually supplies their hydrogen and oxygen requirements

Lipteichoic acids

span the peptidoclcyan layer and is linked to the cell membrane

Bacteria are enclosed in what?

special cell walls made of carbohydrates and proteins called peptidoglycan

Endospores are

special resistant, dormant structure formed within a cell that protects the bacterium from adverse environmental conditions

Inclusion bodies are

specialized structures often present in prokaryotes which may function as energy reserves an for carbon reservoirs or have special functions for motility

We use broths primarily for

specific assays or (rarely) for bacteria that will not form colonies on a solid surface

The dyes we use a usually organic compounds which bind to

specific cellular materials

Larger, uncharged polar molecules such as amino acids cannot pass through the plasma membrane unless three is a

specific transporter protein

What are the shapes of nucleoids

spherical, elongated or dumbbell shaped

Endospore stability may come from

spore specific chemicals such as dipicolinic acid and proteins that protect the DNA.

For many microbes, O2 is an

ssential nutrient; others cannot grow in its presence and may even be killed by it.

The development of a biofilm in vitro involves the following 5 stages

stage 1: reversible attachment of bacterial cells to a surface, Stage 2: irreversible attachment mediated by the formation of exopolymeric (polysaccharides, etc) material, Stage 3: formation of microcolonies and the beginning of biofilm maturation, Stage 4: formation of a mature biofilm with a 3-dimensional structure containing cells packed in clusters with channels between the clusters that allow transport of water and nutrients and waste removal, and Stage 5: detachment and dispersion of cells from the biofilm and initiation of new biofilm formation

Gram-positive bacteria

stain purple/blue and tens to be sensitive to penicillin and cephalosporin antibiotics

One way to visualize these colorless cells is by

staining the specimen

Iodine binds to

starch

After solidifying, agar

stays solid up to nearly 100 degrees Celsius allowing incubation at warm temperatures

The isolation method most commonly used to get pure cultures is the

streak plate method/t-streak/quadrant streak/isolation streak

The 16S rRNA is important for

subunit association and translational accuracy

Many gram-negative prokaryotes can oxidize reduced

sulfur compounds

Elemental sulfure for the oxidation of sulfide may accumulate in the cell in

sulfure granules

the Peroxidation of lipids is a major consequence of exposure to these oxygen forms and the cell possesses various enzymes:

superoxide dismutase, catalase, peroxidase, as well as cellular antioxidants which are able to scavenge oxygen free radicals and repair peroxidized lipids.

Selective media are designed to

suppress/inhibit the growth of unwanted bacteria and encourage the growth of desired microbe

Fluorescence microscopy

takes advantages of fluorescence, the ability of substances to absorb short wavelength of light (UV) and gives off a light at a longer wavelength (visible). Cells may be stained with fluorescent eyes. It is used to visualize location or pattern of fluorescence in cells

The process of endospore formation within a vegetative cell (which is an actively growing cell)

takes several hours and is known as sporulation.

These biofilm communities consist of sessile organisms, meaning

that they grow attached to a surface

When did the Black Death finally leave Europe?

the 19th Century

Sulfur is needed in

the amino acid cystine and methionine and also in vitamins like thiamine and biotin

Nitrogen is used primarily fro

the amino group of amino acid proteins and DNA and RNA synthesis

Biosafety

the application of safety precautions that reduce a scientists' risk of exposure to a potentially infectious microbe and limit contamination of the work environment.

Refraction

the bending of light as it travels through substances with different densities

Many bacteria in biofilms are often resistant to antibiotics because

the biofilm offers a protective barrier

The development of a biofilm allows for the cells inside to become more resistant to

the body's natural antimicrobials as well as the antibiotics (antibiotic resistance) administered in a standard fashion.

The 16S rRNA makes up

the bulk of the 30S subunit

In non acid-fast bacteria lacking lipid components

the carbolsuchsin is removed and leaves cells colorless. A counterstain is applied than these cells will stain blue, distinguishing it from the acid-fast microbes.

When a microbe is in a solution whose concentration of solutes is higher than in the cell (the environment is hypertonic to the cell),

the cellular water passes out through the plasma membrane to the high solute concentration. This osmotic loss of water causes plasmolysis, or shrinkage of the cell's cytoplasm. This will inhibit cell growth

40S monitors

the complementarity between the tRNA anticodon and mRNA

When the flagella motor foes CE,

the flagella gly apartment and the cell tumbels

In a chemostat

the growth chamber is connected to a reservoir of sterile medium. Once growth is initiated, fresh medium is continuously supplied from the reservoir. The volume of fluid in the growth chamber is maintained at a constant. Fresh medium is allowed to enter into the growth chamber at a rate that limits the growth of the bacteria. The bacteria grow (cells are formed) at the same rate that bacterial cells (and spent medium) are removed by the overflow

Thus adding salts to a solution results in

the increase of osmotic pressure which can be used to preserve foods

Gram stain is widely used in medical microbiology to provide

the initial characterization and classification of bacteria.

chemostat relieves

the insufficiency of nutrients, the accumulation of toxic substances, and the accumulation of excess cells in the culture, which are the parameters that initiate the stationary phase (where cell growth is equal to cell death) of the growth cycle

Exoenzymes are classified on the basis of

the kind of molecules they hydrolyze

H. pylori

the main cause of chronic superficial gastritis and is associated with both gastric and duodenal ulcer.

The charge of the dye causes it to bind to

the negatively charged cell components such as the negatively charged backbone of DNA, cell proteins or membranes

The most important feature of the 23S rRNA is

the peptide transferase center, the site where peptide bonds are formed

The lighter areas of a image produced by TEM represents

the places where a greater number of electron were able to pass through

Osmotic pressure

the pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane (like the plasma membrane). It is also defined as the minimum pressure needed to nullify osmosis.

as temperatures rise,

the rate of enzymatic reactions increases and growth becomes faster. However, above a certain temperature, proteins or other cell parts may be denatured or irreversibly damaged.

Gram staining is an important step in

the screening of infectious bacteria for a patient, which could help a doctor prescribe the right course of treatment

Fixed position lenses

the stage moves up and down rather than the lens

The sulfur remains in granules as long as the source of the reduced sulfur from which is was derived from is still present. However, as the reduced sulfur source becomes limiting,

the sulfur granules is oxidized to sulfate and the granules will slowly disappear as the reaction proceeds

SEM is especially useful in studying

the surface structures of intact cells and viruses

Koch's first postulate

the suspected pathogen must be present in all cases of the disease and absent from healthy animals

The resolving power of a microscope is limited by

the wavelength of light

What causes the toxicity of superoxide free radicals

their great instability, which leads them to steal an electron from a neighboring molecule, and this repeats itself.

The Cardinal temperature

there is a minimum temp below which growth is not possible, and optimum temperature at which growth is most rapid, and a maximum temperature above which growth is not possible.

The extraordinary resistance properties of endospores make them of particular importance because

they are not readily killed by many antimicrobial treatments and could be a problem in food and medical industries.

Metals are important elements because

they are used as cofactors in enzymes to stabilize membranes and cell structures

Biofilms can also be a problem in industry:

they can be a problem in pipes and tubing where their accumulations impede circulation, such as in indwelling medical devices, including mechanical heart valves and catheters. Biofilms can do long term damage to water distribution facilities and other public utilities, causing fouling of equipment and contamination of products.

In tact gas vesicles can provide buoyancy because

they have an overall density much less than that of the aqueous medium in which the various organisms grow.

Complex media usually provide the full range of growth factors that may be required by an organism so

they may be more handily used to cultivate unknown bacteria or bacteria whose nutritional requirement are complex

Prokaryotes are monomorphic meaning

they stay the same shape

If anaerobes are placed in an environment with air bubbles, where will they move

they will disperse

Archaea have atypical cell walls because

they wither lack cell walls completely ot have unusual walls made of polysaccharides and proteins, but not peptidoglycan

The prokaryotic plasma membrane is a

thin structure lying inside the cell wall and encloses the cytoplasm of the cell and consists of a phospholipid bilayer with lipid-soluble proteins.

Gas vesicles in cyanobacteria (which are photosynthetic) allow

this species to float up toward the light; allowing them to migrate to the optimal light levels in water column.

Chemostat in microbial physiology

to mimic low substrate concentrations often found in nature and probe which microbes in mixed cultures of known composition can best survive nutrient limitations.

Thioglycollate in the medium serves as a reducing agent

to remove traces of O2 by reducing it to water.

LPS is medically important because when LPS is released from a dead bacterial cell it is

toxic to mammals and is therefore an endotoxin

Microbes require several metals for growth, typically in very small amounts and are referred to as

trace elements

The 23S molecule is involved in

translocation and peptide bond formation

Penicillin actually works by stopping the

transpeptide enzyme from building cross bridges, which ultimately weakens the cell well and leads to osmotic lysis of the cell

The various proteins found int eh cell envelope of gram-negative cells work to

transport

Rusnare interrupted by periodic, abrupt, random changes in direction called

tumbles

every microbe has a pH range

typically about 2- 3pH units, within which growth is possible. Also, each microbe shows a well defined pH optimum, where growth occurs best.

Most bacteria are

unicellular

The element Oxygen is a

universal component of cells and is always provided in large amounts by H2O.

Autotrophs are classified as Photoautotrophs which

use light for photosynthesis

Mannitol Salt agar (MSA)

used to isolate and differentiate Staphylococcus aureus, a common bacterium found in nasal passages. This microbe has a tolerance for high concentrations of sodium chloride, largely because their adaptation to salty habitats such as the human skin. It can also ferment the carbohydrate mannitol to form acid.

The vast majority of microbes are quite

useful

Can small molecules such as water, oxygen, carbon dioxide pass through the plasma membrane?

usually

Enrichment media:

usually a complex medium base to which additional nutrients such as serum or whole blood are added. These added nutrients better mimic conditions in the host and are required for successful lab culture of some human pathogens

Pili form

usually longer than fimbriae and only have 1-2 per cell.

Brightfield illumination is best suited for

utilization with fixed, stained specimens or other kinds of samples that naturally absorb significant amounts of visible light.

Molecular oxygen (O2) requirements

vary between different species of microbes

Given the exponential reproduction rate and the rate of spontaneous mutation

ven a pure bacterial culture will contain spontaneous mutant cells that will vary in their nucleotide sequences from the original cells. Thus the culture is not perfectly homogenous

Microbes produce fermented foods such as

vinegar, cheese, and bread

Light radiation source

visible light

A "colony" is a

visible mass of microbial cells arising form one cell or spore or from a group of the same microbes.

Mycelia

visible masses of mold

Magnetotactic bacteria are being studied for their potential in

wastewater treatment

Defined media is used extensively for

well characterized isolates in the lab, but may not be as useful when the nutritional requirements are unknown for a particular microbe

All of these biosafety levels follow "standard microbiological practices"

which are those practices common to all labs, which include not eating, drinking, or applying cosmetics, washing hands after working in the lab, routinely decontaminating work area.

Blood agar is an enriched medium

which nutritionally rich whole blood supplements the basic nutrients

Hyperthermophiles

with very high temperature optima, often exceeding 85-90degC

Example of unicellular fungi

yeast

Can bacteria be motile?

yes

The early Egyptians knew how to make various microbial fermented food such as

yogurt, beer, wine, bread in nearly 8,000 BC