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85 Cards in this Set
- Front
- Back
Clone |
A population of cells derived from a single cell |
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Strain |
Genetically different cells contained within a clone (colony) |
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Classification of Viruses |
Viruses are not placed in a kingdom. They are not composed of cells and cannot grow without a host cell.A viral species is a population of viruses with similar characteristics that occupies a particular ecological niche. |
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pH requirements for growth |
Most bacteria between pH 6.5 and 7.5 Molds and yeasts grow between 5 and 6 Acidophiles grow in acidic environments |
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Prokaryotic species |
A population of cells with similar characteristics |
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Culture |
Any culture medium grown in laboratory media |
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Culture |
Any culture medium grown in laboratory media |
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Why don't viruses fit into the taxonomical hierarchy structure? |
- Not technically a living organism - No RNA - Acellular |
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Biofilms |
Microbes adhere to surfaces and accumulate on solid surfaces in contact with water. - biofilm a form on teeth, contact lenses, medical implants, etc. - microbes in biofilms are more resistant to antibiotics then free-swimming microbes |
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How do microbes grow? |
They always stay about the same size.
Divide into equal daughter cells. - Population of clones with a few random mutations. |
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What causes plasmolysis? |
Hypertonic environments, or an increase in salt or sugar. *cytoplasm shrinks |
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What chemicals are needed for life to survive? |
Carbon Nitrogen Sulfur Phosphorous Trace Elements |
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Fastidious organisms |
Organisms that require many growth factors |
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Capnophiles |
Microbes that require high CO2 conditions |
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Selective Media Enrichment Culture |
1) Suppress unwanted microbes and encourage desired microbes 2) Encourages growth of desired microbe |
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Why does a colony not grow to an infinite size, or at least fill the confines of the Petri plate? |
Competition for limited resources does not allow unlimited growth |
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Nonsense mutation |
Premature termination of polypeptide |
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Missense mutation |
Incorrect amino acid substituted |
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Silent mutation |
No change in amino acid sequence |
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Induction |
The process that turns on the transcription of a gene. |
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Death phase |
The period of logarithmic decrease in a bacterial population; also called logarithmic decline phase. |
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rRNA |
Ribosomal RNA The type of RNA that forms ribosomes |
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Horizontal Gene Transfer |
Transfer of genes between two organisms in the same generation. |
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Vertical Gene Transfer |
Transfer of genes between two organisms in different generations. |
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Transformation |
genes transferred from one bacteria to another as naked DNA |
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Obligate Anaerobe |
An organism that does not use molecular oxygen (O2) and is killed in the presence of O2 |
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Eukarya |
All eukaryotes (animals, plants, fungi and protists); members of the Domain Eukarya |
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Phototroph |
An organism that uses light as its energy source and carbon dioxide as its carbon source. |
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Aerotolerant Anaerobes |
An organism that does not use molecular oxygen but is not affected by its presence. |
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Repressor |
A protein that binds to the operator site to prevent transcription. |
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Promoter |
The starting site on a DNA strand for transcription of RNA by RNA polymerase. |
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Archaea |
Domain of prokaryotic cells lacking peptidoglycan; one of the three domains |
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Auxotroph |
A mutant microorganism with a nutritional requirement that is absent in the parent. |
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Antisepsis |
A chemical method for disinfection of the skin or mucous membranes; the chemical is called an antiseptic. |
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Semiconservative replication |
The process of DNA replication in which each double-stranded DNA molecule contains one original strand and one new strand. |
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Mesophile |
An organism that grows between about 10 degrees C and 50 degrees C; a moderate-temperature-loving microbe. Humans |
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Sanitization |
The removal of microbes from eating utensils and food preparation areas. |
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Generalized Transduction |
The transfer of bacterial chromosome fragments from one cell to another by a bacteriophage. |
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Asepsis |
The absence of contamination by unwanted organisms |
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Nonionizing radiation |
Short-wavelength radiation that does not cause ionization; UV radiation as an example |
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Psychrophile |
An organism that grows best at about 15degrees C and does not grow above 20 degrees C; a cold-loving microbe |
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log phase |
The period of bacterial growth or logarithmic increase in cell numbers; also called exponential growth phase. |
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Base substitution |
The replacement of a single base in DNA by another base, causing a mutation; also called point mutation. |
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Binary fission |
Prokaryotic cell reproduction by division into two daughter cells |
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RNA primer |
A short strand of RNA used to start synthesis of the lagging strand of DNA, and to start the polymerase chain reaction. |
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Nonsense mutation |
A base substitution in DNA that results in a nonsense codon. |
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Inducer |
A chemical or environmental stimulus that causes transcription of specific genes. |
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Catalase |
An enzyme that breaks down hydrogen peroxide. |
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Microaerophile |
An organism that grows best in an environment with less molecular oxygen than is normally found in air |
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Frameshift mutation |
A mutation caused by the addition or deletion of one or more bases in DNA. *extremely detrimental - permissable only if an entire triplet is removed or added. - Neutral mutation are permissable if triplet codes for the same triplet codon. |
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Obligate aerobe |
An organism that requires molecular oxygen to live. |
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Sterilization |
The removal of all microorganisms, including endospores. |
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Transduction |
The transfer of DNA from one cell to another by a bacteriophage. |
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Autoclave |
Equipment for sterilization by steam under pressure, usually operated at 15 psi and 121 degrees C. |
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Facultative anerobe |
An organism that can grow with or without molecular oxygen. |
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mRNA |
Messenger RNA The type of RNA molecule that directs the incorporation of amino acids into proteins. |
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Stationary phase |
The period in a bacterial growth curve when the number of cells dividing equals the number dying |
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Capnophiles |
A microorganism that grows best at relatively high CO2 concentrations. |
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Nonsense codon |
A codon that does not encode any amino acid |
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Plasmylosis |
Loss of water from a cell in a hypertonic environment. |
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Repression |
The process by which a repressor protein can stop the synthesis of a protein |
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Lagging strand |
During DNA replication, the daughter strand that is synthesized discontinuously. |
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Lag phase |
The time interval in a bacterial growth curve during which there is no growth. |
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thermophile |
An organism whose optimum growth temperature is between 50 degrees C and 60 degrees C. A heat loving microbe |
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DNA polymerase |
Enzyme that synthesizes DNA by copying a DNA template. |
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Missense mutation |
A mutation that results in the substitution of an amino acid in a protein. |
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Specialized transduction |
The process of transferring a piece of a cell DNA adjacent to a prophage to another cell. |
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Hot air sterilization |
Sterilization by the use of an oven at 170 degrees C for approximately 2 hours. |
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Disinfection |
Any treatment used on inanimate objects to kill or inhibit the growth of microorganisms; a chemical used is called a disinfectant. |
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Photolyase |
An enzyme that splits thymine dimers in the presence of visible light. |
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Operon |
The operator and promoter sites and structural genes they control |
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Strain |
Genetically different cells within a clone. |
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Bacterial Growth Curve Phases |
1. Lag Phase - Intense activity prepping for pop. growth 2. Log Phase - Log or exponential increase in pop. 3. Stationary Phase - Period of equilibrium; deaths balance production of new cells 4. Death Phase - Pop. is decreasing at a logarithmic rate |
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Reproduction in Prokaryotes |
Binary Fission - most Budding - Yeast Conidiospores - Fungi Fragmentation of filaments |
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Fastidious |
Organisms that require many growth factors |
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Krebs Cycles |
Decarboxylation of pyruvic acid produces one CO2 molecule and one acetyl group. Two-carbon acetyl groups are oxidized in the Krebs cycle. Electrons are picked up by NAD+ and NAD for the ETC. From one molecule of glucose, oxidation produces six molecules of NADH, two molecules of FADH2, and two molecules of ATP. |
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Alternatives to glycolysis |
Pentose Phosphate Pathway - Uses 5 carbon sugars Entner-Doudoroff pathwayC |
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Cellular Respiration |
ETC - Electron Transport Chain - Does not always require O2 - ATP generated in ETC by oxidative phosphorlyation. |
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Fermentation |
Releases energy from sugars or other organic molecules by oxidation. O2 is not required 2 ATP molecules are produced. |
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How many ATP are produced by eukaryotes and prokaryotes? |
Eukaryotes - 36 ATP molecules Aerobic Prokaryotes - 38 ATP molecules |
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Direct Microscopic Count |
Number of bacteria/ ml = # of cells counted/ Vol. of area counted |
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1. Degerming 2. Biocide/ Germicide 3. Bacteriostasis |
1. removing microbes from a limited area. 2. Killing microbes 3. Inhibiting, not killing, microbes |
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Structure of Operon |
Consists of the promoter and operator sites and structural genes that code for the protein. the operon is regulated by the product of the regulatory gene. |
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1. Base Substitution 2. Missense mutation 3. Nonsense mutation 4. Frameshift mutation |
1. Change in one base 2. Base substitution results in change in amino acid 3. Base substitution results in a nonsense codon. 4. Insertion or deletion of one or more nucleotide pairs. |
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Spontaneous mutations |
occur in the absence of a mutagen. |