Microbiology Exam 2 Study Guide – Flashcards

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Metabolism
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The sum of all chemical reactions, both anabolic and catabolic, within an organism.
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Catabolism
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All of the decomposition reactions in an organism taken together.
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Anabolism
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All of the synthesis reactions in an organism taken together.
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Kinetic Energy
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Energy of motion.
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Potential Energy
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Stored Energy.
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Enzymes
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An organic catalyst.
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Substrates
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The molecule upon which an enzyme acts.
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Products
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The atoms, ions, or molecules that remain after a chemical reaction is complete.
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Electron Carriers
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Carry electrons or electrons and protons. NADH, FADH₂
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Co-enzyme
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Organic cofactor.
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Temperature
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A measure of how hot (or cold) something is; specifically, a measure of the average kinetic energy of the particles in an object.
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Denature
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A change in the shape of a protein (such as an enzyme) that can be caused by changes in temperature or pH (among other things).
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pH
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A logarithmic scale used for measuring the concentration of hydrogen ions in a solution.
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Inhibitors
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An agent that slows or interferes with a chemical action.
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Phosphorylation
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The transfer of a phosphate group, usually from ATP, to a molecule. Nearly all cellular work depends on ATP energizing other molecules.
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Glycolysis
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First-step in the catabolism of glucose via respiration and fermentation.
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Acetyl-CoA
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Combination of two-carbon acetate and coenzyme A.
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Kreb's Cycle
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Series of eight enzymatically catalyzed reactions that transfer stored energy from acetyl-CoA to coenzymes NAD+ and FAD.
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Electron Transport
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A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.
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Aerobic Respiration
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Type of cellular respiration requiring oxygen atoms as final electron acceptors.
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Anaerobic Respiration
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Type of cellular respiration not requiring oxygen atoms as final electron acceptors.
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Fermentation
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In metabolism, the parietal oxidation of sugar to release energy using an endogenous organic molecular rather than an electron transport chain as the final electron acceptor. In food microbiology, any desirable change to food or beverage induced by microbes.
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Beta-oxidation
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A catabolic process in which enzymes split pairs of hydrogenated carbon atoms from fatty acid and join them to coenzyme A to form acetyl-CoA.
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Photosynthesis
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Process in which light energy is captured by chlorophylls and transferred to ATP and metabolites.
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Carbon Fixation
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The attachment of atmospheric carbon dioxide to ribulose 1,5-biphosphate (RuBp).
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Calvin Cycle
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Stage of photosynthesis in which atmospheric carbon dioxide is fixed and reduced to produce glucose.
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Biosynthesis
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Production of phage DNA and proteins
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Biofilms
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A slimy community or microbes growing on a surface.
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Photoautotroph
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Microorganism which requires light energy and uses carbon dioxide as a carbon source.
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Photoheterotroph
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Microorganism that requires light energy and gains nutrients via catabolism of organic compounds.
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Chemoautotroph
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Microorganism that uses carbon dioxide as a carbon source and catabolizes organic molecules for energy.
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Chemoheterotroph
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Microorganism that uses organic compounds for both energy and carbon.
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Trace Element
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Element required in very small amounts for microbial metabolism.
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Aerobic
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Chemical reactions that require the presence of oxygen.
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Anaerobic
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Describes a process that does not require oxygen.
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Facultative Anaerobic
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Microorganism which can across a cell membrane via protein channels.
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Aerotolerant Anaerobe
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Do not use Aerobic Metabolism, but do have some enzymes that detoxify oxygen's poisonous forms, so can grow in its presence.
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Microaerophile
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Microorganism that requires low levels of oxygen.
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Minimum Temperature
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Lowest temperature that permits a microbe's growth and metabolism.
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Optimum Temperature
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Temperature at which organisms grow best.
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Maximum Temperature
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Temperature above which bacterial growth will not take place.
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Psychrophile
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Microorganism requiring cold temperatures (below 20ºC).
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Mesophile
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Microorganism requiring temperatures ranging from 20ºC to about 40ºC
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Thermophile
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Microorganism requiring temperatures above 45ºC.
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Hyperthermophile
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Microorganism requiring temperatures above 80ºC.
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Neutrophile
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Microorganism requiring neutral pH.
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Acidophile
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Microorganism requiring acidic pH.
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Alkalinophile
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Microorganism requiring alkaline pH environments.
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Halophile
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Microorganism requiring a saline environment (greater than 9% NaCl).
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Nitrogen Fixation
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The conversion of atmospheric nitrogen to ammonia.
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Inoculum
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Sample of microorganisms.
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Pure Culture
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Culture containing cells of only one species.
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Colony Forming Unit (CFU)
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A single cell or group of related cells that produce a colony.
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Sterile
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Free of microbial contamination.
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Steak Plate
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Method of culturing microorganisms in which a sterile inoculating loop is used to spread a inoculum across the surface of a solid medium in Petri dishes.
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Petri Dish
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Dish filled with solid medium used in culturing microorganisms.
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Aseptic
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Characteristic of an environment or procedure that is free of contamination by pathogens.
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Culture Medium
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(bacteriology) a nutrient substance (solid or liquid) that is used to cultivate micro-organisms.
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Complex Medium
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Culturing medium that contains nutrients released by the partial digestion of yeast, beef, soy, or other proteins; thus, the exact chemical composition is unknown.
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Defined Medium
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Culturing medium of which the exact chemical composition is known.
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Selective Medium
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Culturing medium containing substances that either favor the growth of particular microorganisms or inhibit the growth of unwanted ones.
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Differential Medium
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Culturing medium formulated such that either the presence of visible changes in the medium or differences in the appearances of the colonies help microbiologists differentiate amount kinds of bacteria growing on the medium.
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Capnophile
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Microorganism that grows best with high levels of carbon dioxide in addition to low levels of oxygen.
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Lyophilized
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Removal of water from a frozen culture or other substance by means of vacuum pressure. Used for the long-term preservation of cells and food.
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Binary Fission
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The most common method of asexual reproduction of prokaryotes, in which the parental cells disappears with the formation of progeny.
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Generation
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Time required for a cell to grow and divide.
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Doubling Time
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Amount of time it takes for a population to double.
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Growth Curve
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Graph that plots the number in a population over time.
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Lag Phase
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Phase in a growth curve in which the organisms are adducting to their environment.
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Log Phase
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Phase in a growth curve in which the population is most actively growing.
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Stationary Phase
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Phase in a growth curve in which new organisms are being produced at the same rate at which older organisms are dying.
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Death Phase
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Phase in a growth curve in which the organisms are dying more quickly than they are being replaced by new organisms.
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Genetics
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The study of inheritance and heritable traits as expressed in an organism's genetic material.
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Genome
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The sum of all the genetic material in a cell or virus.
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Gene
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A specific sequence of nucleotides that codes for a polypeptide or an RNA molecule.
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Nucleotide
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Monomer of nucleic acid, which is composed of a nucleoside and a phosphate.
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Chromosome
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A molecule of DNA associated with protein. In prokaryotes, typically circular and localized in a region of the cytosol called the nucleoid. In eukaryotes, chromosomes are threadlike and are most visible during mitosis and meiosis.
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Plasmid
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A small, circular molecule of DNA that replicates independently of the chromosome. Each carries genes for its own replication and often for one or more nonessential functions such as resistance to antibiotics.
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DNA
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Nucleic acid consisting of nucleotides made up of phosphate, a deoxyribose pentose sugar, and an arrangement of the bases adenine, guanine, cytosine, and thymine.
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Replication
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The process whereby DNA makes a copy of itself before cell division
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Primer
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An already existing RNA chain bound to template DNA to which DNA nucleotides are added during DNA synthesis.
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Replication Fork
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A Y-shaped region on a replicating DNA molecule where new strands are growing.
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Haploid
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A nucleus with a single copy of each chromosome.
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Diploid
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A nucleus with two copies of each chromosome.
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Genotype
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Actual set of genes in an organism's genome.
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Phenotype
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The physical features and functional traits of an organism expressed by genes in the genotype.
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mRNA
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Form of ribonucleic acid that carries genetic information from DNA to ribosome.
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rRNA
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Forms of ribonucleic acid which, together with polypeptides, makes up the structure of ribosomes.
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tRNA
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Form of ribonucleic acid that carries amino acids to the ribosome.
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RNA Polymerase
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Enzyme that synthesizes RNA by linking RNA nucleotides that are complementary to genetic sequences in DNA.
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Genetic Code
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Collection of codons of mRNA, each of which directs the incorporation of a particular amino acid into a protein during protein synthesis.
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Codon
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Triplet of mRNA nucleotides that codes for specific amino acids. For example, AAA is a codon for lysine.
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Anticodon
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Portion of tRNA molecule that is complementary to a codon on mRNA.
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Ribosome
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Nonmembranous organelle found in prokaryotes and eukaryotes that is composed of protein and ribosomal RNA and functions to make polypeptides.
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Operon
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A series of genes, a promoter, and often an operator sequence controlled by one regulatory gene. The operon model explains gene regulation in prokaryotes.
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Repressor
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A protein that binds to an operator and physically blocks RNA polymerase from binding to a promoter site.
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Promotor
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Region of DNA where transcription begins.
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Mutation
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In genetics, a permanent change in the nucleotide base sequence of a genome.
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Mutagen
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Physical or chemical agent that introduces a mutation.
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Base Substitution
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A type of point mutation; the replacement of one nucleotide and its partner in the complementary DNA strand by another pair of nucleotides.
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Missense Mutation
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A substitution in a nucleotide sequence resulting in a codon that specifies a different amino acid: what is transcribed makes sense, but not the right sense.
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Nonsense Mutation
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A substitution in a nucleotide sequence that causes an amino acid codon to be replaces by a stop codon.
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Frameshift Mutation
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Type of mutation in which nucleotide triplets subsequent to an insertion to deletion are displaced, creating new sequences of codons that result in vastly altered polypeptide sequences.
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Carcinogen
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Chemical capable of causing cancer.
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Teratogen
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Ability to cause birth defects.
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Gene Transfer
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Movement of genetic information between organisms.
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Vertical Gene Transfer
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Occurs during reproduction between generations of cells.
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Horizontal Gene Transfer
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Process in which a donor cell contributes part of its genome to a recipient cell, which may be a different species or genus from the donor.
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Conjugation
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In genetics: method of horizontal gene transfer in which a bacterium containing a fertility plasmid forms a conjugation pills that attaches and transfers plasmid genes to a recipient; in reproduction of ciliates: coupling of mating cells.
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Transduction
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Method of horizontal gene transfer in which DNA is transferred from one cell to another via a replicating virus.
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Biotechnology
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Branch of microbiology in which microbes are manipulated to manufacture useful products.
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Restriction Enzymes
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Enzyme that cuts DNA at specific nucleotide sequences and is used to produce recombinant DNA molecules.
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Restriction Fragments
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DNA segment resulting from cutting of DNA by a restriction enzyme.
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Reverse Transcriptase
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Complex enzyme that allows retroviruses to make dsDNA from RNA templates used in recombinant DNA technology to make cDNA.
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Sticky Ends
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Single stranded ends of DNA left after cutting with enzymes.
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PCR
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Technique of recombinant DNA technology that allows researchers to produce large number of identical DNA molecules in vitro.
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Vector
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In genetics and recombinant DNA technology, nucleic acid molecule, such as a vital genome, transposon, or plasmid that is used to deliver a gene tine a cell. In epidemiology, an animal (typically an arthropod) that transmits disease from one host to another.
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Electroporation
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A technique to introduce recombinant DNA into cells by applying a brief electrical pulse to a solution containing cells. The electricity creates temporary holes in the cells' plasma membranes, through which DNA can enter.
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Microenjection
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The process of using a glass micropipette to insert substances at a microscopic or borderline macroscopic level into a single living cell.
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Protoplast Fusion
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The fusing of two protoplasts from different plant species that would otherwise be reproductively incompatible.
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Gene Therapy
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The use of recombinant DNA technology to insert a missing gene or repair a defective gene in human cells.
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Gene Gun
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A device that delivers DNA to cells by micro-projectile bombardment.
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