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An overview of the key characteristics and structures of bacterial cells, including their classification as prokaryotes, the differences between gram-positive and gram-negative cell walls, the role of specialized structures like flagella and endospores, and the mechanisms of antibiotic action. It covers topics such as the three domains of life, cell theory, the characteristics of life, and the various shapes and arrangements of bacteria. The document also discusses important concepts related to bacterial metabolism, gene regulation, and the production of enzymes and toxins. Overall, this document offers a comprehensive understanding of the fundamental aspects of bacterial biology and microbiology, which could be valuable for students studying topics in biology, microbiology, or related fields.
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What is perceived severity?
Define Precontemplation - ANSWER No intention of changing in the next 6 months: "I won't" Define Contemplation
Koch's Postulates - Ans - a sequence of experimental steps for directly relating a specific microbe to a specific disease
Re-emerging diseases - Ans - Once controlled by preventative public health measures, they are now on the rise What factors lead to emerging and re-emerging diseases today? - Ans - - anti- vaccination
aseptic technique - Ans - A procedure performed under sterile conditions. important to reduce contamination acid fast stain procedure - Ans - - heat fix
acid fast reaction for Mycobacterium - Ans - Pink (positive) Ribosomes - Ans - site of protein synthesis Prokaryotic Chromosomes - Ans - consist of a single, circular strand of DNA bacterial plasmids - Ans - used to create recombinant DNA; a tiny ring of DNA carried in the cytoplasm of bacteria 70s ribosomes - Ans - smaller ribosomes found in prokaryotes 80S ribosomes - Ans - larger ribosomes found in eukaryotes polar flagella - Ans - flagella attached at one or both ends of the cell peritrichous flagella - Ans - spread over entire surface of cell axial filaments - Ans - Also called endoflagella Found in spirochetes Anchored at one end of a cell Rotation causes cell to move like a corkscrew. covered by the outer membrane to protect the axial filaments Endospore - Ans - A thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions. vegetative cell - Ans - a cell that has not formed spores or other resting stages The genera of bacteria that have endospores - Ans - Bacillus and Clostridium disease caused by endospores - Ans - anthrax botulism tetanus food poisoning gangrene how do specialized structures (flagella, capsules, endospores) confer specialized capabilities? - Ans - structures that provide the cell with motility allow the bacterium to navigate to or away from certain environments. endospores allow the cell to remain dormant for years if the environment is lacking any necessary nutrients. cell wall function - Ans - provides support and protection
competitive inhibition - Ans - Competitive inhibition is a process by which a chemical substance has a shape that fits the active site of an enzyme and competes with the substrate, effectively inhibiting the enzyme. noncompetitive inhibition - Ans - In noncompetitive inhibition, the inhibitor binds with the enzyme at a site other than the active site and inactivates the enzyme by altering its shape. Extracellular enzymes - Ans - Enzymes that are synthesised and secreted to work outside the cell. Why must antibiotics that act as enzyme inhibitors be taken multiple times throughout the day? - Ans - To maintain high levels of concentration of the inhibitor so that it will always beat the substrate. Sulfa Drugs-Competitive Inhibitors - Ans - sulfa drugs target the synthesis of folic acid. To effectively inhibit this pathway, the sulfa drug must bind to the enzyme's active site since it has a very similar structure as the original substrate for this pathway Explain how the product in a metabolic pathway may control its own synthesis. - Ans - when enough product has been produced, it may bind to the inhibitor and induce a halt to synthesis of that pathway. beta-galactosidase - Ans - an enzyme that catalyzes the conversion of lactose into monosaccharides Amylase - Ans - Enzyme in saliva that breaks the chemical bonds in starches Catalase - Ans - An enzyme produced in all cells to decompose hydrogen peroxide, a by-product of cell respiration Lipase - Ans - pancreatic enzyme necessary to digest fats into fatty acids constitutive genes - Ans - genes that are expressed all the time repressible genes - Ans - genes are on and can be turned off inducible genes - Ans - Genes whose expression is turned on by the presence of some substance. Regulate catabolic pathways. repressible enzymes - Ans - function in anabolic pathways; their synthesis is repressed by high levels of the end product inducible enzymes - Ans - An enzyme whose transcription can be stimulated by an abundance of its substrate (as opposed to repressible enzyme). Usually in catabolism.
constitutive enzymes - Ans - always present, always produced in equal amounts or at equal rates, regardless of the amount of substrate disulfide bridges - Ans - covalent bonds that may further reinforce the shape of a protein. strong bonds that have a higher denaturation temperature, so are commonly found in hyperthermophiles. catalase producing bacteria - Ans - use oxygen beta galactosidase producing bacteria - Ans - use lactose amylase producing bacteria - Ans - digest carbohydrates lipase producing bacteria - Ans - digest lipids Exotoxins - Ans - toxic substances that bacteria secrete into their environment ex. Clostridium Gene - Ans - A segment of DNA on a chromosome that codes for a specific trait Genotype vs. Phenotype - Ans - An organism's genotype is the set of genes that it carries. An organism's phenotype is all of its observable characteristics gene expression - Ans - process by which a gene produces its product and the product carries out its function Promotor - Ans - A region of DNA with a specific sequence that tells RNA polymerase where to begin transcription. operator - Ans - Region of DNA that controls RNA polymerase's access to a set of genes with related functions. inducible operon - Ans - structural genes are not transcribed unless an inducer is present repressible operon - Ans - Usually on; binding of a repressor to the operator shuts off transcription metabolic pathway - Ans - Begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product. Pathogenicity - Ans - ability to cause disease