Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
130 Cards in this Set
- Front
- Back
|
Protozoa have what two basic cell types?
|
Cysts and Traphozoites (Eukaryotes)
|
|
|
How do trophozoites differ from cysts?
|
Cysts have a sac with a distinct cell wall containing fluid and is usually in a dormant stage.
|
|
|
Which Protozoa cell type has a cell wall?
|
Cysts
|
|
|
What structures can protozoa have?
|
Pseudopods, Flagella or Cillia
|
|
|
What are Flagella?
|
A single (or more) appendage from the surface that aids in movement or nutrition.
|
|
|
What is an undulating membrane?
|
A highly modified flagellum on some protozoa, consisting of a finlike extension of the limiting membrane with the flagellar sheath; wavelike rippling of the undulating membrane produces a characteristic movement.
|
|
|
What are cilia?
|
Short, hairlike, rhythmically motile projections of some eukaryotic cells such as Protozoa.
|
|
|
What is the only pathogenic protozoan ciliate?
|
Balantidium coli which causes a diarrhea-type infection. Cysts pass out of the intestines of the infected host and are ingested by the next host (fecal-oral route).
|
|
|
What are the medically important genera of flagellated Protozoa?
|
Trypanosoma Brucei Gambiens, Giardia Lamblia and Trichomonas Vaginalis
|
|
|
Which flagellated protozoa can make cysts?
|
Giardia Lamblia
|
|
|
Which flagelatted protozoa has an undulating membrane?
|
Trichomonas Vaginalis
|
|
|
Define the flagellated protozoa Giardia lamblia.
|
cause a gastrointestinal infection called giardiasis. Cysts pass out of the intestines of the infected host and are ingested by the next host (fecal-oral route).
|
|
|
Define the flagellated protozoa Trichomonas vaginalis.
|
Infects the vagina and the male urinary tract. It does not produce a cysts stage and is usually transmitted by sexual contact.
|
|
|
Define the flagellated protozoa Trypanosoma brucei gambiens.
|
Causes African sleeping sickness and is transmitted by the bite of an infected Tsetse fly.
|
|
|
Define Apicomplexan protozoa.
|
A large group of protists, most of which possess a unique organelle called an apical complex, ring stage or oocyst (but not all together). They are unicellular, spore-forming, and exclusively parasites of animals. Motile structures such as flagella or pseudopods are absent except in certain gamete stages.
|
|
|
Are Apicomplexan protozoa obligate parasites of humans or animals?
|
Animals
|
|
|
Name the medically important genera of Apicomplexan Protozoa.
|
Babesia Microti, Cryptosporidium, Cyclospora, Isospora, Plasmodium, Toxoplasma Gondii
|
|
|
Name the medically important genera of Apicomplexan Protozoa that have a ring stage.
|
Plasmodium
|
|
|
Name the medically important genera of Apicomplexan Protozoa that have oocysts.
|
Toxoplasma Gondii, Cryptosporidium and Cyclospora
|
|
|
Define the Apicomplexan Protozoa Plasmodium.
|
Causes malaria and are transmitted by the bite of an infected female Anopheles mosquito. They reproduces asexually by schizogony in human liver cells and red blood cells but also reproduce sexually by gametes in the mosquito.
|
|
|
Define the Apicomplexan Protozoa Toxoplasma gondii.
|
A intracellular apicomplexan and causes toxoplasmosis. It can infect most mammals and is contracted by inhaling or ingesting cysts from the feces of infected domestic cats, where the protozoa reproduce both asexually and sexually, or by ingesting raw meat of an infected animal. Toxoplasmosis is usually mild in people with normal immune responses but can infect the brain, heart, or lungs of people who are immunosuppressed. It can also be transmitted congenitally and infect the nervous system of the infected child
|
|
|
Define the Apicomplexan Protozoa Cryptosporidium.
|
An intracellular parasite that causes diarrhea, although in people who are immunosuppressed it can also cause respiratory and gallbladder infections. It is transmitted by the fecal-oral route.
|
|
|
In brightfield microscopy, how is magnification calculated?
|
The ocular times (X) the objective lense
|
|
|
In brightfield microscopy, What is the purpose of the condenser & in what position should it be kept in order to
maximize resolution? |
To diret the lamplight onto the slide – always wide open.
|
|
|
In brightfield microscopy, what is the field of view?
|
The diameter of the circle of view you can see when looking down a microscope.
|
|
|
In brightfield microscopy, what is working distance?
|
Working distance is the distance between the objective lens and the specimen.
|
|
|
In brightfield microscopy, what is resolving power?
|
The ability of a microscope or telescope to measure the angular separation of images that are close together
|
|
|
In brightfield microscopy, How is resolving power determined?
|
Resolving power is determined not just by resolution but also by the quality and alignment of it's lenses, mirrors, and other optical elements.
|
|
|
In brightfield microscopy, how is resolving power affected by light of a longer or shorter wavelength?
|
Short wavelengths of light have more energy and provide a crisper image. The image produced by a light microscope is related to the wavelength of light used to create the image. Short wavelengths can give a sharper image because short wavelengths have greater resolving power.
|
|
|
In brightfield microscopy, what is the numerical aperature -
|
The numerical aperture of a microscope objective is a measure of its ability to gather light and resolve fine specimen detail at a fixed object distance.
|
|
|
In brightfield microscopy, what affect does a larger numerical aperature have on resolution?
|
The higher the numerical aperture of the total system, the better the resolution.
|
|
|
In brightfield microscopy, how is resolving power affected by switching from low power to oil immersion?
|
Greater
|
|
|
In brightfield microscopy, how is magnification affected by switching from low power to oil immersion?
|
Greater
|
|
|
In brightfield microscopy, how is feild of view affected by switching from low power to oil immersion?
|
Smaller
|
|
|
In brightfield microscopy, how is working ditance affected by switching from low power to oil immersion?
|
Smaller
|
|
|
Describe yeast cells.
|
They are essentially unicellular and have multicellular structures called pseudohypae.
|
|
|
What structures does yeast have?
|
Multicellular structures called pseudohypae.
|
|
|
How does yeast reproduce?
|
Most reproduce asexually by budding, although a few do so by binary fission.
|
|
|
Name a medically important yeast.
|
Candida albicans ---Yeasts of the Candida genus are another group of opportunistic pathogens which causes oral and vaginal infections in humans, known as Candidiasis. Candida is commonly found as a commensal yeast in the mucus membranes of humans and other warm-blooded animals.
|
|
|
Describe the medically important yeast - Candida Albicans.
|
Candida albicans is a diploid fungus (a form of yeast), which is capable of sexual reproduction but not of meiosis, and a causal agent of opportunistic oral and genital infections in humans
|
|
|
Describe mold growth.
|
Hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Hyphae grow at their tips. As a hypha extends, septa may be formed behind the growing tip to partition each Hypha. Each Hyphae can break off and form new mold.
|
|
|
Describe Hyphae in molds.
|
They are the main mode of vegetative growth, and are collectively called a mycelium in Molds.
|
|
|
Describe Conidia in molds.
|
Conidia, sometimes termed conidiosporesare asexual, non-motile spores of a fungus; They are also called mitospores due to the way they are generated through the cellular process of mitosis. They are haploid cells genetically identical to the haploid parent, can develop into a new organism if conditions are favorable.
|
|
|
What are Sporangiospores?
|
A sporangium is a plant, fungal, or algal structure producing and containing spores. Their spores are sometimes called sporangiospores.
|
|
|
What are Mycelium?
|
A collection of Hyphae in molds.
|
|
|
What are aseptic techniques?
|
It is the prevention of microbial contamination of themselves, which may result in infection, contamination of the environment they are working in and contamination of the specimen they are working on, which is especially important when a pure culture is desired.
|
|
|
What are some examples of aseptic techniques?
|
Flame Sterilization of loops, tubes, Sterilizing work area, washing hands or wearing gloves.
|
|
|
What is a general purpose medium?
|
A general purpose medium used for cultivating a broad variety of fastidious and non-fastidious microorganisms with non-exacting nutritional requirements.
|
|
|
What is a differential medium?
|
This type of media uses the biochemical characteristics of a microorganism growing in the presence of specific nutrients. This type of media is used for the detection of microorganisms and by molecular biologists to detect recombinant strains of bacteria.
|
|
|
What is a selective medium?
|
Selective growth media are also used in cell culture to ensure the survival or proliferation of cells with certain properties, such as antibiotic resistance or the ability to synthesize a certain metabolite.
|
|
|
In exercise 6, Bacteria was isolated from what locations for cultivation (hint- aireborne and swabbed)?
|
Coughing on the agar plate and swabbing the skin with a nutrient broth.
|
|
|
What is the purpose of the simple staining procedure?
|
The use of a single stain to color a bacterial cell. Many bacteria are transparent. Simple staining gives the cells contrast, making them visible. All cells will appear the same color, except endospores which are not stained. Cell shape and cellular arrangement can be observed.
|
|
|
Is heat used in Simple Straining?
|
Yes
|
|
|
What dyes are used for Simple Staining?
|
Methylene Blue, Basic Fuchsin or Crystal Violet.
|
|
|
How many dyes are applied in Simple Staining?
|
One
|
|
|
Using the Gram Staining procedure, bacteria are divided into what two groups?
|
Gram Negative and Gram Positive
|
|
|
What is the counterstain in Gram Staining?
|
Safranin
|
|
|
What is the decolorizing agent in Gram Staining?
|
Acetone Alcohol
|
|
|
What is the (liquid) mordant in Gram Staining?
|
Gram’s Iodine
|
|
|
What is the primary stain in Gram Staining?
|
Crystal Violet
|
|
|
What cell structure determines an organism’s reaction to Gram staining?
|
The Cell Wall
|
|
|
Gram Negative Bacteria appears as what color and means what?
|
Gram-negative organisms will appear red or pink because they are counterstained; due to presence of higher lipid content, after alcohol-treatment, the porosity of the cell wall increases & hence the Crystal violet -Iodine can pass through.
|
|
|
Gram Positive Bacteria appears as what color and means what?
|
Gram-positive bacteria stain dark blue or violet. Their cell wall is typically rich with peptidoglycan.
|
|
|
Name two genera that produce endospores.
|
Bacillus and Clostridia
|
|
|
How are endospores formed?
|
In unfavorable conditions, it divides asymmetrically. This results in the creation of two compartments, the larger mother cell and the smaller forespore. Next (Stage III), the peptidoglycan in the septum is degraded and the forespore is engulfed by the mother cell, forming a cell within a cell. This is followed by the final dehydration and maturation of the endospore (Stages VI+VII). Finally, the mother cell is destroyed in a programmed cell death, and the endospore is released into the environment. The endospore will remain dormant until it senses the return of more favorable conditions.
|
|
|
What is the primary stain in Spore Staining?
|
Malachite Green
|
|
|
At the end of the procedure what cells are stained in Spore Staining?
|
Endospores
|
|
|
How do endospores differ from other bacterial cells?
|
They are resistant to heat, radiation, acids, and many chemicals. They also can survive unfavorable nutrient conditions.
|
|
|
What is the (liquid) mordant in Spore Staining?
|
Water and Heat
|
|
|
Is heat used in Spore Staining?
|
Yes, boiled water underneath the slide for 8 minutes
|
|
|
What is the decolorizing agent in Spore Staining?
|
None
|
|
|
What is the counterstain in Spore Staining?
|
Safranin
|
|
|
What is the primary stain in acid-fast staining?
|
Carbolfuchsin
|
|
|
What is the decolorizing agent in acid-fast staining?
|
Acetone Alcohol
|
|
|
What is the counterstain in acid-fast staining?
|
Methylene Blue
|
|
|
Name a genus of acid-fast bacteria.
|
Mycobacterium and Nocardia
|
|
|
At the end of the procedure what cells are stained?
|
Mycobacteria appears as red and non-acid-fast bacteria or tissue appears blue.
|
|
|
What are Capsules?
|
Capsules are produced by some bacteria and yeasts. Special procedures must be used to visualize capsules called capsular staining.
|
|
|
What dye is used in Capsular Staining for the positive stain?
|
Maneval’s Stain
|
|
|
Are the capsules stained in Capsular Staining?
|
No, they appear as halo’s
|
|
|
A combination of what two types of staining are used in Capsular staining?
|
Simple and Negative staining are combined.
|
|
|
In Capsular Staining, what is negatively stained?
|
The Background medium
|
|
|
What dye is used in Capsular Staining for the negative stain?
|
Congo Red
|
|
|
In Capsular Staining, what is positively stained?
|
The Cells apart from the Capsules
|
|
|
What is the first step in studying and identifying a particular organism?
|
Create a streak or pour plate.
|
|
|
Can isolated colonies be used to generate a pure culture?
|
Yes
|
|
|
What is a pure culture?
|
A pure (or axenic) culture is a population of cells or multicellular organisms growing in the absence of other species or types.
|
|
|
How are pure cultures generated from a streak plate?
|
Diluting the bacterial cells in a sample to an end point where a single cell divides giving rise to a single pure colony.
|
|
|
What is the difference between dilution and dilution factor?
|
Dilution factor is the reciprocal of the dilution
|
|
|
What is the formula for calculating the number of cells per ml?
|
Cells per ml = # colonies/ml plated X (times) dilution factor
|
|
|
What is the formula for calculating a dilution?
|
Dilution = sample volume/final volume or sample volume/sample volume + dilution blank volume
|
|
|
0.1 ml of a bacterial culture was added to a tube containing 9.9 ml of water. After mixing, 0.1 ml from this tube was plated giving rise to 87 colonies. How many cells/ml were in the original culture?
|
Answer: 87,000 or 8.7 x 10 to the 4th
|
|
|
SOLVE: One ml of a bacterial culture was added to a bottle containing 99 ml of water.
After mixing, 1 ml from this bottle was added to a second bottle containing 99 ml of water. After mixing, 1 ml from the second bottle was added to a third bottle containing 99 ml of water. After mixing, 1 ml from the third bottle was plated giving rise to 72 colonies. How many cells/ml were in the original culture? |
Answer: 72,000,000 or 7.2 x 10 to the 7th
|
|
|
What are 3 factors that affect microbial growth?
|
Oxygen, Temperature and pH.
|
|
|
What is aerotolerant?
|
Organism that can grow in oxygen but do not use it as a terminal electron acceptor, they are indifferent to the presence of oxygen
|
|
|
What organisms did we study in the exercise on Effects of Oxygen on Growth?
|
E. Coli, S. Aureus, B. Subtilis and S. Faecalis
|
|
|
What is an obligate anaerobe?
|
Organism which is NOT oxygen tolerant
|
|
|
What is a facultative anaerobe?
|
Oragnism that can grow with oxygen or by other means without oxygen like fermentation
|
|
|
What is an obligate aerobe?
|
Organism that requires oxygen for growth
|
|
|
What is a thermophile?
|
Optimal growth between 50°C and 80°C
|
|
|
What is a psychrotroph?
|
Organisms that are capable of growth and reproduction in cold temperatures. Below 15°C
|
|
|
What is a psychrophile?
|
Optimal growth between - 5°C and 20°C
|
|
|
What is a mesophile?
|
Optimal growth between 20°C and 50°C
|
|
|
What Microorganisms are affected by pH?
|
pH affects the growth of all microorganisms including bacteria and yeast.
|
|
|
Which prefers a lower pH, yeast or Bacteria?
|
Usually yeasts prefer a lower pH than bacteria.
|
|
|
UV light does not penetrate what?
|
Plastic and Endospores
|
|
|
What kinds of cells are killed if exposure if long enough?
|
Bacteria - Non-endospore formers
|
|
|
How (in what settings) can UV light be used to control microbial growth?
|
Laboratory, to sterilize work areas and transfer hoods used for the inoculation of cultures.
|
|
|
What specific part of a cell is damaged by UV light?
|
DNA
|
|
|
Do the alcohol swabs so prevalent in the medical community work well?
|
Yes
|
|
|
Do alcohol swabs effectively remove transient bacteria from the skin?
|
Yes
|
|
|
Is alcohol an effective antiseptic?
|
Yes
|
|
|
What is the difference between resident and transient bacteria?
|
Resident Bacteria is the microorganisms constant in the oral flora and skin (sweat and sebaceous glands) of an individual. Transient Bacteria is mobile by being transferred onto an individual via a mechanism (air, touch, sex) or transferred to a mechanism from an individual.
|
|
|
Do alcohol swabs remove any resident bacteria from the skin?
|
Some but not the sub-dermal resident bacteria.
|
|
|
Can alcohol swabs be used to sterilize the skin?
|
NO
|
|
|
How can the effectiveness of chemicals be evaluated?
|
Using the filter paper disk method of evaluation, inoculate a plate with microorganism, dip paper disk in chemical, place on place, incubate for 48hrs, evaluate the zone of inhibition.
|
|
|
What did a zone of inhibition of growth indicate?
|
To quantitatively compare one agent’s effectiveness against other chemical substances.
|
|
|
What is a bacteriostatic?
|
The preventing of a microorganism from growing, reproducing and multiplying but possibly not killing them.
|
|
|
What is a disinfectant?
|
An agent, such as heat, radiation, or a chemical, that disinfects by destroying, neutralizing, or inhibiting the growth of disease-carrying microorganisms.
|
|
|
What is an antiseptic?
|
A substance that tends to inhibit the growth and reproduction of microorganisms when applied to living tissue.
|
|
|
Were all the chemicals tested equally effective against a single organism?
|
No
|
|
|
Was a specific chemical equally effective against different bacteria?
|
Yes, Bleach
|
|
|
What is the Cell Shape,Cell Arrngmt, Gram Reaction, Staining Prcess of Pseudomonas Arginesa?
|
Pseudomonas Arginesa:
Cell Shape: Rod Cell Arrngment: Single Gram Reaction: Gram - Staining Process Gram |
|
|
What is the Cell Shape,Cell Arrngmt, Gram Reaction, Staining Prcess of Staphylococcus Aureus?
|
Staphylococcus Aureus:
Cell Shape: cocci Cell Arrngment: Irreg. Clusters Gram Reaction: Gram + Staining Process: Gram |
|
|
What is the Cell Shape,Cell Arrngmt, Gram Reaction, Staining Prcess of Bacillus Subtillis?
|
Bacillus Subtillis:
Cell Shape: Rod Cell Arrngment: Chains Gram Reaction: Gram + Staining Process: Spore |
|
|
What is the Cell Shape,Cell Arrngmt, Gram Reaction, Staining Prcess of Micrococcus Luteus?
|
Micrococcus Luteus:
Cell Shape: Cocci Cell Arrngment: Tetrads Gram Reaction: Gram + Staining Process: Gram |
|
|
What is the Cell Shape,Cell Arrngmt, Gram Reaction, Staining Prcess of Branamella Catarrhalis?
|
Branamella Catarrhalis:
Cell Shape: Cocci Cell Arrngment: Pairs Gram Reaction: Gram - Staining Process: Gram |
|
|
What is the Cell Shape,Cell Arrngmt, Gram Reaction, Staining Prcess of Klebsiella Pneumonia?
|
Klebsiella Pneumonia:
Cell Shape: Rod Cell Arrngment: Single Gram Reaction: Gram - Staining Process: Capsule |
|
|
What is the Cell Shape,Cell Arrngmt, Gram Reaction, Staining Prcess of Mycobacterium Phlei?
|
Mycobacterium Phlei:
Cell Shape: Rod Cell Arrngment: Single Gram Reaction: Gram + Staining Process: Acid-fast |
|
|
What is the Cell Shape,Cell Arrngmt, Gram Reaction, Staining Prcess of Serratia Marcescens?
|
Serratia Marcescens:
Cell Shape: Rod Cell Arrngment: Single Gram Reaction: Gram - Staining Process: Single |
