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Micro 8-12
Term | Definition |
---|---|
Gene transfer | refers to the movement of genetic information between organisms |
Recombination | the combing of genes (DNA) from (2) different cells; the resulting cell is referred to as a recombinant |
Vertical gene transfer | when genes pass from parents to offspring (eukaryotic) |
Lateral / horizontal gene transfer | (bacteria)-when they pass genes to other microbes of their same generation |
horizontal / lateral-Forms of transfer | Transformation; Transduction; Conjugation |
Eukaryotic | Sexual Reproduction: Male & Female parents produce gametes (sex cells), which unite to form a zygote, the first cell of a new individual; Gamete Diversity |
Prokaryotic | Horizontal / Lateral |
Naked DNA | DNA that has been released from an organism. Often after the cell is lysed (ruptured), and the DNA is no longer incorporated into chromosomes or other structures (Pieces) |
Competence factor | In this stage, a protein is released into the medium and apparently facilitates the entry of DNA |
Competent | Cells can now take up DNA fragments |
Bacteriophage (transduction) | DNA are carried by these |
Virulent phage | Is capable of causing infection &, eventually, the destruction & death of a bacterial cell; Infection / death of a cell. This cycle results in lysis (rupture) of the infected (host) cell (called: lytic cycle) |
Temperate phage | Ordinarily does not cause a disruptive infection. Instead, the phage DNA is incorporated into a bacterium's DNA and is replicated w/ it |
Lysogency | persistence of prophage without phage replication and destruction of the bacterial cell (cells containing a prophage are said to be lysogenic-ticking time bomb) |
Conjugation | like transformation & transduction, genetic information if transferred from one bacterial cell to another; 1. It requires contact b/w donor and recipient cells; 2. It transfers much larger quantities of DNA (occasionally whole chromosomes) |
Plasmids | Are small extrachromosomal DNA molecules; Bacterial cells often contain several different plasmids that carry genetic information for various nonessential cell functions |
(2) Types of F plasmid cells | F+ (male / donor); F- (female / recipient) |
F+ cells (fertile) | Contain extrachromosomal DNA called F (fertility) plasmids |
F- cells | Lack (do not have) F plasmids |
Promiscuous | Plasmids can sometimes transfer into species other than their own kind |
Transposition | The ability of a genetic sequence to move from one location to another |
Gene amplification | Is a process by which plasmids, or in some cases bacteriophages, are induced to reproduce with cells at a rapid rate |
Hybridomas | Are often made by fusing an antibody-producing plasma cell and a cancer cell |
Classification | The grouping of related organisms together; 1. To establish the criteria for identifying organisms; 2. To arrange related organisms into groups; 3. To provide important information on how organisms evolved |
Taxonomy | Is the science of classification |
Carolus Linnaeus | Is credited w/ founding the science of taxonomy |
Binomial nomenclature | System that is still used today to name all living things |
Strain | Is a subgroup of a species w/ one or more characteristics that distinguish it from other subgroups of the same species |
Dichotomous key | Paired statements describing characteristics of organisms. Paired statements present an "either-or" choice, so that only one statement is true |
Five Kingdom Classification System | Kingdom Monera; Kingdom Protista; Kingdom Fungi; Kingdom Plantae; Kingdom Animalia |
Viruses | Are acellular infectious agents that are smaller than cells; They have not been assigned to a kingdom (non-living); Not included in binomial nomenclature scheme |
Genetic homology | Similarity of DNA |
Polyacrylamide Gel Electrophoresis (PAGE) Method | separates proteins based on molecular size; Protein profiles are produced by this |
Ribosomes | Serve as sites of protein synthesis in both prokaryotic and eukaryotic cells; ; Have evolved slowly; 16S |
Obligate intracellular parasites | Viruses that take over the host cell; Virus hi-jack's host cell & makes more virus |
Nucleic acid core (virus) | DNA or RNA, not both |
Capsid (virus) | Surrounding protein coat |
Envelope (virus) | Surrounding lipid bilayer membrane |
Virion | A complete virus particle, including its envelope, if it has one |
Host range | Refers to the spectrum of hosts that a virus can infect. Different viruses can infect bacteria, fungi, algae, protozoa, plant, vertebrates, or even invertebrates |
Viral specificity | Refers to the specific kinds of cells a virus can infect |
ICTV | International Committee of Taxonomy of Viruses; meets every 4 years and establishes the rules for classifying viruses |
Retroviruses | Are enveloped viruses that have (2) complete copies of (+) sense RNA; HIV - Human Immunodeficiency Virus leads to AIDS - Acquired Immune Deficiency Syndrome |
Latency | The ability to remain in host cells, usually in neurons, for long periods and to retain the ability to replicate |
Latent period | Spans from penetration up to the point of phage release |
Bacterial lawn | A layer of bacteria |
Plaques | Represent areas where viruses have lysed host cells; shows as clear areas |
Lysogeny | A stable, long-term relationship b/w the phage and its host in which the phage nucleic acid becomes incorporated into the host nucleic acid |
Primary cell cultures | Come directly from the animal and are not subcultured (in vitro) |
Continuous cell line | Consists of cells that will reproduce for an extended number of generations |
HeLa cell line | The most famous of (continuous cell line); Named after Henrietta Lacks; She died in 1951 of Cervical Cancer; Genome = isolated HPV |
Teratogenesis | Is the induction of defects during embryonic development |
TORCH series | These tests detect antibodies made against Toxoplasma (a protozoan), other disease-causing viruses (usually including the hepatitis B virus and the varicella, or chickenpox virus), rubella virus, CMV, and HSV |
Oncogenes | The proteins produced by tumor viruses that cause uncontrolled host cell division come from segments of DNA |
Apicomplexans (or sporozoans) | Are parasitic and immobile; associated w/ malaria; Enzymes present in groups (complexes) of organelles at the tips (apices) of their cells digest their way into host cells |
Malaria | In any given year it strikes up to 500 million people and claims the lives of 1.5 to 3 million a year, many of them are children; In Gambia, childhood mortality from this fell by an astonishing 63% after the introduction of these nets. |
Sterilization | The killing or removal of all microorganisms in a material or on an object |
Disinfection | The reduction of the number of pathogenic microorganisms to the point where they pose no danger of disease |
Antiseptic | A chemical agent that can safely be used externally on living tissue or destroy microorganisms or to inhibit their growth |
Disinfectant | A chemical agent used on inanimate objected to destroy microorganisms. Most do not kill spores |
Sanitizer | A chemical agent typically used on food-handling equipment and eating utensils to reduce bacterial numbers so as to meet public health standards. May refer to thorough washing w/ soap and detergent |
Bacteriostatic agent | An agent that inhibits the growth of bacteria |
Germicide | An agent capable of killing microbes rapidly; some such agents effectively kill certain microorganisms but only inhibit the growth of others |
Bactericide | An agent that kills bacteria; Most such agents do not kill spores |
Viricide | An agent that inactivates viruses |
Fungicide | An agent that kills fungi |
Sporocide | An agent that kills bacterial endospores or fungal spores |
Binomial (two-name) system - (first name) | Designates the GENUS of an organism, and its first letter IS capitalized |
Binomial (two-name) system - (second name) | Is the SPECIFIC EPITHET, and it is NOT capitalized, even when derived from the person who discovered it |
Binomial (two-name) system - (both names) | Together the genus and specific epithet identify the SPECIES to which the organism belongs; Both words are italicized in print but underlined when handwritten; When there is no danger of confusion, the genus name may be abbreviated to a single letter. |
Envelopes (advantages) | Envelopes help viruses infect new cells by fusion of the envelope w/ the host's cell or plasma membrane |
Envelopes (disadvantages) | Environmental conditions that destroy membranes: increased temperatures, freezing and thawing, pH below 6 or above 8, lipid solvents, and some chemical disinfectants such as chlorine, hydrogen peroxide, and phenol – will also destroy the envelope. |
Virology | Is a scientific field of study, is only about 100 years old |
Virus Families (distinguished by) | First on the basis of their: nucleic acid type; capsid symmetry (shape); envelope; size |
Plaque assay | The viral assay method that is used |
Three (3) human viruses | Cytomegalovirus (CMV), herpes simplex virus (HSV) types 1 & 2, and rubella- account for a large number of teratogenic effects |
Cytomegalovirus (CMV) infections | Are found in about 1% of live births; of those, about 1 in 10 eventually die from the CMV infection; Most of the defects are neurological, and the children have varying degrees of mental retardation |
The Control of Microbial Growth | A definite proportion of the organisms die in a given time interval; The fewer organisms present, the shorter the time needed to achieve sterility; Microorganisms differ in their susceptibility to antimicrobial agents |
Bactericidal | Kills Bacteria |
Bacteriostatic | Inhibits the growth of bacteria |
Denaturation | Alterations to a protein structure |
Lyophilization | Freeze-drying; is the drying of material from the frozen state |
Catalase (Biochemical Test) | Hydrogen peroxide (H2O2) is poured over heavy growth of an organism on an agar slant; release of O2 gas bubbles indicates this presence, which oxidizes H2O2 to H2O & O2. |
Oxidase (Biochemical Test) | 2 or 3 drops (or a disk) of this test reagent are added to an organism growing on an agar plate; a color change of the test reagent to blue, purple, or black indicates the presence of cytochrome oxidase. |
Genome (component) | Function: Carries the genetic information necessary for replication of new phage particles. |
Tail Sheath (component) | Retracts so that the genome can move from the head into the host cell's cytoplasm. |
Plate and tail fibers (component) | Attach phage to specific receptors sites on the cell wall of a susceptible host bacterium. |