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Micro
2nd exam Microbial Growth
| Question | Answer |
|---|---|
| Binary Fission? | Most common means for bacterial expansion |
| Generation time? | Time required for bacterial population to double (binary fission) |
| Direct count? | Using specialized slides to view bacteria for counting |
| Coulter counter? | Electronic device that counts cells if too concentrated may be inaccurate |
| Serial Dilutions? | Reducing concentration of bacteria by "diluting" samples to obtain an easily countable number of colonies |
| (Alternatives) Fragmentation? | some cyanobacteria grow as a filament then break away |
| (Alternatives) Budding? | An extension swells and forms another smaller cell that then breaks off |
| (Biofilms) Biofilms? | Mixed communities of different kinds of bacteria and other microbes |
| Pioneer? | Initially attaches to a surface then other microbes attach to either the pioneer or their secreted substance |
| Quorum Sensing? | Cells are stimulated to RELEASE CHEMICALS as the population grows to monitor its size |
| Nutrients? | Are acquired from the environment and used for cellular activities |
| Essential nutrients? | Any substance, element or molecule, that MUST be provided to an organism |
| Macronutrients? | Required in large quantities play principal roles in CELL STRUCTURE AND METABOLISM |
| Micronutrients (trace elements)? | Smaller amounts involved in ENZYME FUNCTION and maintenance of PROTEIN STRUCTURE |
| Organic nutrients? | Contains carbon and hydrogen atoms usually the product of LIVING THINGS |
| Inorganic nutrients? | Atom or simple molecule that contains a combination of atoms other than carbon and hydrogen |
| (carbon sources) Heterotroph? | An organism that must obtain its carbon in organic form dependent on other life forms FEEDING ON OTHERS |
| (carbon sources) Autotroph? | SELF FEEDER Organism that uses inorganic co2 as its carbon source Have the capacity to convert co2 into carbon compounds Not nutritionally dependent on other living things |
| Nitrogen is? | 79% of atmosphere Not used for structure of proteins, DNA, RNA & ATP |
| Ammonium? | Sole N source by most organisms |
| Nitrogen fixation? | uses NH2 to produce ammonia |
| (oxygen sources) Oxygen Plays an important role in? | Structure Enzymatic functions Major component of Carbohydrates, lipids, nucleic acids & proteins |
| Aerobic? | With oxygen |
| Anaerobic? | Without oxygen |
| Obligate? | Restricted to specific mode of life |
| Facultative? | Capable but not restricted |
| Aerobic respiration? | Principal energy-yielding (ATP) pathway in animals protozoa fungi and aerobic bacteria |
| Oxygen sources? Oxygen has? | The greatest impact on microbial growth |
| Microbes fall into one three categories | Those that use oxygen and can detoxify it Those that can neither use oxygen nor detoxify it Those that do not use oxygen but can detoxify it |
| C. Perfringens can cause? | Gas gangrene |
| (Detoxification of ROS) Reactive organ species are? (ROS) | created from aerobic respiration these can be toxic to organisms |
| How does catalase work? | - no bubbles + bubbles |
| (carbon dioxide requirements) Capnophiles? | Grows best at a higher CO2 tension than is normally present in the atmosphere Important in the isolation of some pathogens incubation is carried out in a CO2 incubator that provides 3 to 10% CO2 |
| How microbes feed? | Absorption Transport occurs across the cell membrane cell wall is too nonselective to screen the Entrance or exit of molecules |
| Symbiosis break down? | Sym= together Bio= Life |
| Symbiosis? | Living together |
| What are the 3 forms of symbiosis? | mutualism Commensalism parasitism |
| Mutualism? | Mutually benefit relationship BOTH (E. coli) |
| Commensalism? | Relationship benefits one member but not the other commensal coinhabitant (staphylococcus) |
| Commensal? | Receives benefits |
| Coinhabitant? | Host that is neither harmed nor benefitted |
| Parasitism? | Relationship with one member being harmed (H1N1) |
| Nonsymbiotic associations? | Antagonism Antibiotic Synergism |
| Antibiosis? | Is a form of Antagonism |
| Synergism? | An interrelationship between two or more free living organisms that benefit both but is not necessary for their survival |
| Saprobic Microorganisms? | Fungi and bacteria decomposers of plant litter animal matter and dead microbes important in recycling nutrients held in organic materials |
| Most Saprobes? | Have a rigid cell wall and cannot engulf large Bacteria and fungi Release exoenzymes into the environment to digest food into smaller particles that can be transported into the cell |
| Parasitic microorganisms? (4) | Ectoparasites endoparasites intracellular parasites Obligate parasites |
| Ectoparasites? | Live on the body |
| Endoparasites? | Live in organs and tissues |
| Intracellular parasites? | Live within cells |
| Obligate parasites? | Unable to live outside of a living host |
| Diffusion? | The movement of molecules in a gradient from an area of higher density or concentration to an area of lower density or concentration diffusions Across a cell membrane is determined by the concentration gradient and the permeability of substance |
| osmosis? | The membrane is selectively or differentially permeable has passageways that allow the passage of water but not other dissolved molecules |
| Osmophiles? | Live in habitats with high solute concentration |
| Obligate Halophiles? | Require high concentrations of salt for growth 9 to 25% Have a significant modification to their cell walls and membranes and will lyse in hypotonic habitats |
| Facultative halophiles? | Resistant to salt even though they do not normally reside in high salt environments |
| Isotonic? | The salute concentration in external environments is EQUAL to the cells internal environment |
| Hypotonic? | swells External solute Concentration is lower than cells internal environment water moves into the cell cells without walls swell and can burst (cytolysis) |
| Hypertonic | shrink External salute concentration is higher than inside the cell high osmotic pressure forces water to leave the cell sells shrinks (plasmolysis) |
| what does the amoeba utilize? | Vacuoles that constantly moves excess water out of the cell requires energy ATP |
| What are the environmental factors that influence microbes? | Heat Cold Gasses acid radiation osmotic pressure hydrostatic pressure other microbes |
| What is saturation? | How quickly or slow microbes absorb |
| What is competition? | Affinity AKA attraction |
| Cardinal temperatures? | Ranges for temperature for the growth of a given microbial species Minimum temperature maximum temperature Optimum temperature |
| Minimum temperature? | The lowest temperature that permits A microbes continued growth and metabolism |
| Maximum temperature? | Highest temperature at which growth in metabolism can precede If temperature rises slightly above maximum growth will stop If the temperature continues to rise enzymes and nucleic acids will become denatured or permanently inactivated |
| Optimum temperatures? | Intermediate temperature ranges between minimum and maximum promotes the fastest rate of growth and metabolism |
| Psychrophiles? | Capable of growth 0 Celsius and cannot grow above 20 Celsius I |
| psychrotrophs? | Grow slowly in the cold 15 C TO 30 C |
| Mesophiles? | Most human pathogens 30 Celsius to 40 Celsius likes body temps |
| Thermoduric? | Microbes survive short exposure to high temperatures |
| Thermophiles? | Grow optimally at temperatures above 45 Celsius associated with volcanic activity |
| Extreme Thermo files? | Grow between 80 Celsius and 121 Celsius |
| Barophiles? | Deep in the sea microbes that exist in pressures up to 1000 times atmospheric pressure Ocean |
| Alkalinophiles? | Live in hot pools and soils that contain high levels of basic minerals bacteria that decompose urine create alkaline conditions |
| Obligate acidophiles? | Require an acidic environment for growth |
| pH? | The degree of acidicity or alkalinity of a solution |
| Phototrophs? | Can use visible light rays as an energy source Protect against radiation Yellow pigments Uses enzymes to overcome the damage effects of UV radiation on DNA |
Created by:
hw0993422