Test Answers on Microbiology Lecture Exam #1 – Flashcards
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Unlock answersType of bacteria that lives in harsh conditions. |
Archaea |
Cells of animals, plants, fungi, and protist |
Eukaryotic Cells |
Contain membrane-bound organelles that compartmentalize the cytoplasm and perform specific functions. |
Eukaryotic cells |
No nucleus or other membrane-bound organelles. |
Prokaryotic Cells |
Contain double-membrane bound nucleus with DNA chromosomes. |
Eukaryotic cells |
Basic shape of cells |
spherical, cubical, and cylindrical |
Internal content |
cytoplasm, surrounded by a membrane...DNA chromosome(s), ribosomes(synthesized protiens), metaboic capabilities. |
1st Characteristic of Life |
Reproduction and heredity-genome composed of DNA packed in chromosomes; produce offspring sexually or asexually. |
2nd characteristic of life |
Growth and development |
3rd characteristic of life |
Metabolism-chemical and physical life processes |
4th chacteristic of life |
Movement and/or irritability-respond to internal/external stimuli; self-propulsion of many organisms. |
5th characteristic of life |
cell support, protection, and storage mechanisms - cell walls, vacuoles, granules and inclusions |
6th characteristic of life |
Transport of nutrients and waste |
Cellular structure and function is amazingly versatile and adaptable |
Prokaryotic cell |
Appendages, flagella, Pili, Fimbriae, Glycocalyx-capsule, slime layer |
Prokaryotic cell (external) |
Cell wall, cell membrane |
Prokaryotic cell (cell envelope) |
cytoplasmic matrix, ribosomes, inclusions(stored material), nucleoid/chromosome(DNA), actin cytoskeleton, endospore (has crust coating and is entirely different metabolic state) |
Prokaryotic cell (Internal) |
Because of their small size prokaryotic cells... |
appear featureless and two dimensional when viewed with an ordinary microscope. |
category of prokaryotes with pepidoglycan in their cell walls |
Bacteria |
organizing, classifing, and naming living things is called |
Taxonomy |
orderly arrangement of organisms into groups is called |
classification |
assigning names is called |
nomenclature |
determining and recording traits of organisms for placement into taxonomic schemes... |
identification |
Levels of Classification...1,2,3 |
1. Domain (Archaea, Bacteria, & Eukarya) 2. Kingdom 3. Phylum or Division |
Levels of Classification 4,5,6 |
4. class 5. order 6. family |
Levels of classification 7,8 |
7. Genus 8. Species |
Plants, Animals, Fungi, Protists |
Domian Eukarya |
Cyanobactera, Chlamydias Spirochetes, Gram-positive bacteria, Endospore producers, Gram-negative bacteria |
Domain Bacteria |
Binomial (scientific) nomenclature |
Geives each microbe 2 names: Genus - which is captialized species - which is lower case Both of which are italicized or underlined |
natural relatedness between groups of organisms is called |
Phylogeny |
-All new species originate from preexisting species. -Closely related organism have similar features because they evolved from common ancestral forms. |
Evolution |
Methane producers, Prokaryotes that live in extreme salt, Prokaryotes that live in extreme heat |
Domain Archaea |
true bacteria |
Bacteria |
odd baceria that live extreme environments, high salt, heat, etc. |
Archaea |
Have a nucleus and organelles. |
Eukarya |
Process by which chemical substances (nutrients) are acquired from the environment and used in cellular activites. |
Nutrition |
Must be provided to an organism |
Essential Nurtients |
These nutrients are required in large quantities; play principal roles in cell structure and metabolism. * Proteins, carbbohydrates |
Macronutrients |
The nutrients are required in small amounts; involved in enzyme function and maintenance of pretein structure. *Manganese, zinc, nickel |
Micronutrients or trace elements |
Contain carbon and hydrogen atoms and are usually the products of living things. *Methane (CH4), carbohydrates, lipid, proteins, and nucleic acids |
Organic nutrients |
Atom or molecule that contains a combination of atoms other than cargon and hydrogen (no carbon) *Metals and their salts, gases, and water |
Inorganic nutrients |
70% water Proteins 96% of cell is composed of these 6 elements:
|
Carbon Hydrogen Oxygen Phosphorous Sulfur Nitrogen
|
Must obtain carbon in an organic form made by other living organisms such as proteins, carbohydrates, dipids, and nucleic acids. |
Heterotroph |
Producers of an Eco-system |
Autotroph |
an organism that uses CO2 an inorganic gas as its carbon source. *Not nutritionally dependent on other living things. |
Autotroph |
Organic compounds that cannot be synthesized by an organism because they lack the genetic and metabolic mechanisms to synthesize them |
Essential Organic Nutrients |
Growth factors must be provided as a nutrient such as... |
Essential amino acids and vitamins |
Sources of Essential Nutrients |
Carbon sources (Heterotroph and Autotroph) |
Main determinants of nutritional type are: |
Carbon source-heteroph and autotroph Energy source-chemotroph and phototrophs |
gain energy from chemical compounds |
Chemotroph |
gain energy through photosynthesis |
Phototrophs |
Photoautotroph is an autotroph that gets its CO2 from what energy source |
Sunlight ex: organisms, such as algae, plants, cyanobacteria |
Chemoautotroph is an autotroph that gets it CO2 from what energy source |
Simple inorganic chemicals ex: Only certain bacteria, such as methanogens, deep-sea vent bacteria |
Chemoheterotroph is an Hetetotroph/Organic that get its energy source from |
Metabolic conversion of the nutrients from other organisms ex: Protozoa, fungi, many bacteria, animals |
What is a Saprobe (Chemoheterotroph) energy source |
Metabolizing the organic matter of dead organisms ex: Fungi, bacteria (decomposers) |
What is a Parasite (Chemoheterotroph) energy source |
Utilizing he tissues, uids of a live host ex: Various parasites and pathogens; can be bacteria, fungi, protozoa, animal. |
A Photoheterotroph (Hetertroph/organic) that gets its energy from |
Sunlight or organic matter ex: Purple and green photosynthetic bacteria |
Photoautotrophs survive by |
Oxygenic photosynthesis and Anoxygenic photosynthesis |
Chemoautotrophs (lithoautotrophs) survive |
totally on inorganic substances |
Methanogen is a kind of chemoautotroph that... |
produce methane gas under anaerobic conditions |
Majority of Heterotrophs are chemohetertrophs which survive on... |
Aerobic respiration |
Free-living microoorganisms that feed on organic detritus from dead organisms *Opportunistic pathogen *Facultative parasite are called: |
Saprobes |
They derive nutrients from host *Pathogens *Some are obligate parasites |
Parasites |
Type of transport that does not require energy; substances exist in a gradient and move from areas of higher concentration toward areas of lower concentration: |
Passive transport |
List types of passive transports: |
Diffusion, Osmosis, and Facilitated diffusion |
moves down concentration gradient |
Diffusion |
diffusion of water |
Osmosis |
requires a carrier |
Facilitated diffusion |
Type of transport that requires energy and carrier proteins: gradient independent: |
Active transport |
transported molecule chemically altered |
Group translocation |
endocytosis (moves into the cell), exocyosis (goes outside fo the cell), pinocytosis |
Bulk transport |
6 I's; of culturing microbes |
Inoculation, Isolation, Incubation, Inspection, Information gathering, and Identification |
Introduction of a sample into a containter of media to produce a culture of observable growth is called |
Inoculation |
Seperating one species from another is called |
Isolation |
Under conditions that allow growth... |
Incubation |
Isolation techniques include: |
Streak plate technique Pour plate technique Spread plate technique |
Media can be classified by what three state: |
Physical state Chemical composition Functional type |
liquid (TSB), simisolid, and solid |
Physical state |
synthetic (chemically defined) and nonsynthetic (complex) |
Chemical composition |
general purpose, enriched, selective, differential, anaerobic growth, specimen transport, assay, enumeration |
Functional type (Purpose of Medium) |
Type of media that can be chemically defined is called |
Synthetic |
Type of media that is complex and is not chemically defined |
Nonsynthetic |
liquid medium containing beef extract and peptone |
Nutrient broth |
solid media containing beef extract, peptone (which is a partial digested protien), and agar |
Nutrient agar |
The most commonly used solidifying agent is called |
Agar |
A complex polysaccharide (sugars) isolated from red algae |
Agar |
Agar is solid at room temperature, liquiefies at boiling (100 C), and does not re-solidify until it cools at____ |
42 C |
What does Agar do? |
Provides framework to hold moisture and nutrients and is not digestivle for most microbes. |
Media that contains pure organic and inorganic compounds in an exact chemical formula |
Synthetic |
Media that contains at least on ingredient that is not chemically definable. |
Complex or nonsynthectic |
Media that grows a broad range of microbes, usually nonsynthetic. |
General purpose media |
Media that contains complex organic substances such as blood, serum, hemoglobin, or special growht factors required by fastidious (hard to grow) microbes. |
Enriched Media |
Contains one or more agents that inhibit growth of some microbes and encourage growth of the desired microbes. |
Selective Media |
Allows growth of several types of microbes and displays visible differences amound thos microbes. |
Differential Media |
Contains a substance that absorbs oxygen or slows penetration of osygen into mediam; used for growing anaerobic bacteria. |
Reducing medium |
Contains sugars that can be fermented converted to acids, and a pH indicator to show this reaction. |
Carbohydrate fermentation medium |
Temperature-controlled chamber |
Incubation |
observation; macroscopic and microscopic |
Inspection |
grows only single known species of microorganisms |
Pure culture |
hold two or more identified species or microoorganisms |
Mixed cultures |
once pure or mixed uclture that has unwanted microbes growing |
Contaminated culture |
macroscopic and microscopic appearance, biochemical test, genetic characteristics, immunological testing |
Identification |
What two way are potentially hazardous cultures and specimens disposed? |
-Steam Sterilization (Autoclave) -Inceneration (Burning) |
Division of bacterial cells occurs mainly through |
Binary fission |
Parent cell enlarges, duplicates its chromosome, and forms a central transverse septum dividing the cell into two daugher cells.; This is called |
Binary Fission |
Time requied for a complete fission cycle is called the |
generation or doubling time |
Each new fission cycle increases the population by a factor of |
2-exponential growth |
Formula for calculating population size over time: |
Nf = (N1)2n ; Nf total # of cells in the population N1 is starting number of cells Exponentn denotes generation time 2n number of cells in that generation |
In laboratory studies, population typically display a predictable patter over time called |
growth curve |
Stages in the normal growth curve include: |
Lag Phase, Exponential growth phase, Stationary phase, and Death phase |
"flat" period of adjustment, enlargement; little growth is called |
Lag Phase |
A period of maximum growth withll continue as long as cells have adequate nutrients and favorable environment. |
Exponential growth phase |
Rate of cell growth equals rate of cell death caused by depleted nutrients and O2, excretion of organic acids and pollutants. |
Stationary phase |
As limiting factor intensify, cells die exponentially. |
Death phase |
Degree of cloudiness, turbidity, reflects the relative population size.; This is called |
Turbidometry |
Getting a viable colony count or direct cell count of all cells present; automated or manual is called |
Enumeration of bacteria |
What can pick up fine degrees of difference in turbidity? |
Spectrophotometer |
Evenly cloudy thoughout |
uniform fine turbidity |
produces a type of surface membrane |
pellicle |
appears to clump (suspended chunks or pieces) |
Flocculent |