Flashcards in Chapter 6 Deck (171)
All organisms require a source of these elements _____.
CHNOPS stands for
carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur, represents the six most important chemical elements whose covalent combinations make up most biological molecules on Earth.
All organisms need other atomic elements in ____.
______ needed for building molecules in the cell.
______ use carbon dioxide. Not nutritionally dependent on other living things.
______ use organic carbon.
______ used to generate (ATP) to run cell processes.
____ use chemical compounds for an energy source.
_____ use light as an energy source.
______ use sunlight (nonliving environment) as an energy source.
The carbon source for photoautotroph is ____.
The carbon source for chemoautotroph is ____.
The energy source (nonliving environment) for chemoautotrophs is ____.
_____ energy source is obtained by metabolizing the organic matter of dead organisms.
_____ energy source is obtained by utilizing the tissues, fluids of a live host.
_____ energy source is sunlight and the carbon source is organic.
_____ energy source is metabolic conversion of the nutrients from other organisms.
The carbon source for heterotrophs is ___.
The carbon source for autotrophs is ____.
Two types of chemoheterotrophs
Saprobes are free living organisms that feed on organic detritus from ____.
Saprobes are ____ of plants, animal matter, and dead microbes.
_____ recycle organic nutrients
______ are the majority of microbes causing human disease.
____ obtain nutrients from host cells/tissues.
Parasites often cause damage to tissues or ____.
_____ live on the body.
_____ live in organs and tissues.
____ live within cells.
____ unable to grow outside of a living host.
Microbes eat by transporting nutrients across the ______.
_____ and _____ are the forms of movement from an area of higher concentration to an area of lower concentration. ______ uses protein channels.
passive transport and facilitated diffusion
_______ are using proteins and energy to move against a concentration gradient.
Microbes eat via 3 methods
The concentration of solutes in an environment can affect _____. Too much can be detrimental.
The availability of water is critically important because cytoplasm contains up to ___ water.
Halophiles like high ____ environments.
Extreme halophiles include some archaea that require ____ salt for growth.
15% - 30%
______ can tolerate higher salt concentrations.
i.e. staphylococcus is an example remember MSA
Living membranes block the entrance and exit of larger molecules and permit the free movement of _____. (_____)
osmosis in living things
Osmotic relationships between cells and their environment is determined by the relative _____ of the solutions on either side of the cell membrane.
______ is the diffusion of water through a selectively permeable membrane.
Passageways in the permeable membrane allow free diffusion of water, but block ____.
Osmosis continues until the concentration is ____ on both sides of the membrane.
_____ is the environment is equal in solute concentration tot eh cell's internal environment.
In isotonic relationships there is ____ net change in cell volume. (stable)
Generally the most _____ environment for cells is isotonic.
______ is when the solute concentration outside the cell is lower than inside the cell.
A slightly hypotonic environment can be _____ to bacteria cells.
Pure water provides the most _____ environment for cells because it has no solute.
The net direction of osmosis is from the ____ solution into the cell, and cells without walls swell and can _____.
Slight hypotonicity is tolerated quite well by most bacteria because of their ______ walls.
_____ is when the environment has a higher solute concentration than the cytoplasm.
A cell membrane will shrivel up inside the cell wall, plasmolysis, because there is not enough water, ______, left to keep it rigid.
Fresh pond water is an example of _____ conditions. In bacteria the cell wall protects them from _______. Amoeba (protozoa without cell wall) have a water ______ that moves excess water back out of the cell.
High salt environment is an example of _____ conditions. ____ living in the Great Salt Lake absorb salt to make their cells more isotonic with the environment.
The range of temperatures for the growth of a given microbial species can be expressed as _____ cardinal temperatures.
The range of temperatures for the growth of a given microbial species can be expressed as what three cardinal temperatures.
The ____ is the lowest temperature that permits a microbe's continued growth and metabolism; below this temperature, its activities are inhibited
The _____ is the highest temperature at which growth and metabolism can proceed. IF the temperatures rises slightly above maximum, growth will stop, but if it continues to rise beyond that point, the enzymes and nucleic acids will eventually become permanently inactivated (denatured) and the cell will ____.
The ____ covers a small range, intermediate between the minimum and maximum, which promotes the fastest rate of growth and metabolism (rarely is the optimum a single point).
Psychrophiles optimum temperature is below ___.
Psychrophiles cannot grow above ____.
Psychrophiles when stored at refrigerator temperature ____ rather than ______ them.
incubates rather than inhibits
The natural habitats of psychrophiles include natural habitats lakes, rivers, snowfields, polar ice, and _____.
Microbial cells are unable to control their temp and therefore take on the ambient temperature of their ____.
Microbial cells survival is dependent on adapting to whatever temp variations are encountered in that ____.
Amoebas and certain white blood cells ingest whole cells or large solid matter by a type of endocytosis called ____.
Liquids, such as oils or molecules in solution, enter the cell through a type of endocytosis called ___.
Chemicals that are necessary for particular organsims, which they cannot manufacture by themselves, are called ____.
Depending on their natural habitats, some microbes have a ___ cardinal range, and others a ___ one.
The typhus bacterium multiplies only in the range of 32C to 38C, and the ______ multiply most succesfully in tissues that are slightly below normal body temperatures (33C to 35C). Both have a ___ cardinal range.
Strains of Staphylococcus aureus growth within the range of 6C to 46C, and the intestinal bacterium _____ grows within the range of 0C to 44C, which is a broad cardinal range.
Another way to express temperature adaptation is to describe whether an organism grows optimally in a ____, ___, or ____ temperature range.
cold, moderate, or hot
When the temperature adaptation is described as cold, moderate, or hot it is in reference to these 3 ecological groups.
psychrophile, mesophile, thermophile
Psychrophiles are rarely pathogenic because _____.
they have an optimum temperature of below 15C, which is much lower than the normal temperature of the body which is 37C.
Psychrotrophs grow ____ in the cold.
Psychrotrophs optimum temperature is between ___C to ____C.
25C to 30C
_________ can grow in your refrigerator and in food on the counter to cause food-borne disease.
Examples of psychrotrophs
The majority of medically significant mircroorgansims are _______, organisms that grow at intermediate temperatures.
The optimum growth temperature of _____ is 30C to 40C.
Human pathogens are ____ because the human internal body temperature is 37C, and the skin is closer to 30C.
Mesophiles inhabit _____, ____, and ____ as well as soil and water in temperate, subtropical, and tropical regions.
humans, animals, and plants
_____ microbes, which can survive short exposure to high temperatures but are normally mesophiles, are common contaminants of heater or pasteurized foods.
Examples of Thermoduric microbes
______ grows optimally at temps greater than 45C.
Thermophiles DNA and enzymes are ______ to high temps.
The general range of growth of thermophiles is _____.
45C to 80C.
_____ grow well between 80C and 120C.
Strict thermophiles are so heat tolerant that researchers may use an ____ to isolate them in culture.
Heat loving microbes live in soil and water associated with ____ , in compost piles, and in habitats directly exposed to the sun.
The atmospheric gases that most influence microbial growth are ____ and _____, of these _____ gas has the greatest impact on microbial growth.
O2 and CO2
Not only is oxygen an important respiratory gas, but it is also a powerful ____ agent that exists in many toxic forms.
As oxygen enters cellular reactions, it is transformed into several toxic products (4)
singlet oxygen (O)
superoxide ion (O2-)
hydroxyl radicals (OH-)
hydrogen peroxide (H2)2)
_____ is an extremely reactive molecule. It is one of the substances produced by phagocytes to kill invading _____.
The buildup of singlet oxygen and the oxidation of membrane lipids and other molecules can damage and destroy a ___.
Microbes fall into one of three categories.
1. those that use oxygen and detoxify it
2. those that cannot use oxygen nor detoxify it
3. those that do not need oxygen but can detoxify it
Bacteria growing in O2 need to deal with toxic oxygen products. Two step process requires two enzymes: ______ and _____.
catalase (most common)
Step 1: 2O2- + 2H+ -SUPEROXIDE DISMUTASE--> H2O2 (hydrogen peroxide) + O2
and step 2: _____
2H2O2 --CATALASE --> 2H20 + O2
If a microbe is not capable of dealing with toxic oxygen by these or similar mechanisms, it is forced to live in habitats free of ____.
_____ is similar to catalase in function, but no O2 is released.
_____ can't grow without oxygen.
_____ likes oxygen, but can grow without it.
_____ can't tolerate any oxygen.
_____ can tolerate oxygen, but does not use it.
_____ requires small % of oxygen.
_______ grow best at a higher CO2 concentration than is normally present in the atmosphere.
Examples of Capnophiles
_____ is the acidity or alkalinity of a solution.
pH scale 0-14
The pH of pure water is ____.
Most organisms live in habitats between pH ___ and pH ___ because strong acids and bases can be damaging to the cell.
pH 6 - pH 8
_____ prefer neutral (close to 7) pH.
____ prefer a basic/alkaline ph.
Example of Alkaliphiles
Proteus species and UTI's
____ grow in an acidic environment.
Example of Acidophiles
Lactobacillus and vaginal flora
Examples of Aerobes
most fungi, protozoa, and many bacteria, such as Bacillus species and Mycobacterium tuberculois
Examples of Microaerophiles
Organisms that live in soil or water or in mammalian hosts, not directly exposed to atmosphere; Helicobacteri pylori, Borrelia burgdorferi
Examples of faculative anaerobes
many gram-negative intestinal bacteria, staphylococci
Examples of anaerobes
Many oral bacteria, intestinal bacteria
Examples of Aeroteolerant anaerobes
certain lactobacilli and streptococci, clostridial species
Most microbes live in ____.
Interactions between microorganisms can have beneficial, harmful, or ____.
no particular effects on teh organisms involved
Ecological associations among microorganisms can be obligatory or ____ to the members.
Ecological associations among microorganisms often involve ____.
The ocean depths subject organisms to increasing hydrostactic pressure. Deep-sea microbes called ______ exist under pressures that range from a few times to over 1,000 times the pressure of the atmosphere. These bacteria are so strictly adapted to high pressures that they will rupture when exposed to _____ atmospheric pressure.
______ is where two organisms live together in close partnership.
_____ is when organisms lives in an obligatory mutually beneficial relationship.
_____ is when the host organism provides the parasitic microbe with nutrients and a habitat; _______ usually harms the host in some way.
________ is the member called the commensal receives benefits, while its co-inhabitant is neither harmed nor benefited.
S. aureus produces & releases
nutrients that Haemophilus
influenzae requires for growth.
• Haemophilus will grow in
satellite colonies near S. aureus
•S. aureus does not (but is not
_____ is a relationship between two or more free living organisms that is not necessary for their survival.
______ is an interrelationship between two or more free living organsisms that benefits them but is not necessary for their survival. The members cooperate and share _____.
Gum disease, dental caries, and some bloodstream infections involve mixed infections of bacteria interacting _____.
_______ is an association between free-living species that arises when members of a community compete.
Biofilms are an example of ____
_____ form on many surfaces including teeth, lungs, catheters, pace makers, respiratory tubing, etc
______ are mixed communities of different kinds of bacteria and other microbes that are attached to a surface and to each other, forming a multilayer conglomerate of cells and intracellular material.
Bacteria uses _____ to interact with other members of the same species, as well as members of other species that are close by.
________, mechanism by which bacteria regulate gene expression in accordance with population density through the use of signal molecules. ________ allows bacteria populations to communicate and coordinate group behaviour and commonly is used by pathogens (disease-causing organisms) in disease and infection processes.
Biofilms are ____ to most antibiotic treatments.
The growth of eukaryotic microorganisms can occur in various ways, but bacteria most often grow using a unique process called ____.
Individual cell size does not increase before the actual fission event, but the most relevant aspect of growth is in their _____.
Steps in formation of a biofilm
1: pioneer bacteria colonize a surface
2. pioneers secrete extracellular material that helps keep them on the surface and serves as attachment point for later colonizers. Quorom sensing chemicals (red dots) are released by bacteria.
3. In many (but not all) biofilms, other species join and may contribute to the extracellular matrix and/or participate in quorum sensing with their own chemicals or the ones released by other species.
4. Biofilms serve as a constant source of bacteria that can "escape" and become free-living again
Binary fission refers to the fact that one cell become ___.
Steps in binary fission of rod-shaped bacterium.
1. a young cell
2. chromosome is replicated and new and old chromosome move to different sides of cell.
3. protein band forms in center of cell
4. septum formation begins
5. when septum is complete, cells are considered divided in to two daughter cells (genetically identical). Some species will separate, while others remain attached, forming chains or doublets for examples
_____ is asexual
_____ or ____ is the time required for a complete binary fission cycle.
generation or doubling time
_____ increases the population by a factor of two.
As long as the environment remains favorable, the doubling effect can continue at ____.
a constant rate
The average generation time for bacteria is _____ minutes under optimum conditions. The shortest generation times can be 10 to 12 minutes.
30 to 60 minutes
Mycobacterium leprae, the cause of Hansen's disease, has a generation time of _____ days as long as that of some animals.
10 to 30 days
Environmental bacteria commonly have generation times measured in ___.
Most pathogens have relatively ____ doubling times.
Salmonella enteritidis and Stphylococcus aureus, bacteria that cause food-borne illness, double in ____, which is why leavign food at room temperature has caused many cases of food-borne disease.
20 to 30 minutes
i.e. in a few hours , a population
____ is represented by 2 to the, 2 to the 2, 2 to the 3, etc. 2 to the n, n = ________.
Poltting logarithm number provides a ______, plotting raw data gives a _____.
Stages in the normal growth curve
1. lag phase
2. exponential growth phase
3. stationary phase
4. death phase
some cells remain viable
The alternative is an automatic growth chamber called the _____, or continuous culture system.
define stagesof bacterial growth curve
We can ____ bacterial population growth in liquid media by measuring the change in turbidity.
______ measures light passing through tube. As the broth gets "cloudier" less light comes through the side.
Turbidity is correlated with _____, but its not an exact number.
_____ is a glass slide with a geometrical grid etched on it.
When counting bacterial numbers you put your sample on this grid and view _____. Grids are uniform and represent a given volume so you can calculate the _____.
under the microscope.
number of cells per volume
Determine CFU/ml of the original sample by plating a sample and ____.
counting the resulting colonies
1 colony = ____ cell in original sample