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This study guide provides a comprehensive overview of key concepts in microbiology, covering topics such as the characteristics of life, macromolecules, cell structure, prokaryotic and eukaryotic cells, cellular metabolism, and microscopy. It includes numerous questions and answers, making it a valuable resource for students preparing for their final exam in biod 171.
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What is microbiology the study of? - ANSWER-microbes and their biological processes What is the smallest biological unit of life? - ANSWER-cell What are the characteristics of life? - ANSWER-movement, responsiveness, growth, reproduction, metabolism, homeostasis, and organization What is a macromolecule? - ANSWER-a complex molecule that is composed from smaller subunits What are the four main types of macromolecules? - ANSWER-protein, lipids, nucleic acids, carbohydrates What is the most prominent macromolecule in the body? - ANSWER-protein What are the functions of proteins in a cell? - ANSWER-Movement, catalyzing, support, storage, transportation, communication in the cell, defense what is the most abundant cell type? - ANSWER-Prokaryotic What are the two major types of nucleic acids and their roles? - ANSWER-DNA and RNA DNA contains a vast amount of hereditary information and is responsible for the inheritable characteristics of living organisms. RNA is responsible for deciphering the hereditary information in DNA and using it to synthesize proteins. What is the plasma membrane and what is it made of? - ANSWER-The plasma membrane serves the cell as a surrounding barrier that separates the inside of the cell from the outside surrounding environment. The plasma membrane also restricts the movement of materials (water, nutrients, etc) either in or out of the cell, thus allowing a cells to absorb and keep what is needed (influx) while also preventing the escape (out flux) of essential nutrients. The plasma membrane is composed of lipids (hydrophobic hydrocarbons). What are the three main components of carbohydrates? - ANSWER-carbon, hydrogen, oxygen
What is the primary difference between prokaryotic and eukaryotic cells? - ANSWER- Eukaryotic cells contain a nucleus, a membrane enclosed region within the cell that contains the genetic material. Prokaryotic cells do not have a nucleus and can be further classified as either Bacteria or Archaea. What are the main morphologies of bacteria? - ANSWER-coccus (round/spherical), bacillus (rod), vibrio (curved rod) or spirillum (spiral/corkscrew) what are the 2 main branches of prokaryotes? - ANSWER-bacteria and archaea Which group of microbes is noted for its ability to survive under harsh conditions? - ANSWER-Archaea What are the four main classifications of Eukarya? - ANSWER-Animalia, Plantae, Fungi or Protista Can viruses be classified as either prokaryotic or eukaryotic? - ANSWER-No they are not considered living because What is the lipid bilayer of the plasma membrane composed of? - ANSWER-polar hydrophilic (water loving) head group and a non-polar hydrophobic (water fearing) tail region -hydrophobic tail faces inward and and polar head interacts with water outside and inside the cell What are the primary cellular organelles and their roles? - ANSWER-Ribosomes (protein synthesis), ER (site of protein synthesis), Golgi (protein modification and distribution), lysosomes (waste disposal), mitochondria (ATP generation) and chloroplasts (plants only; site of photosynthesis). Proteins are formed from various combinations of ______ of which there are ____ known forms - ANSWER-amino acids, 20 What is an essential amino acid? - ANSWER-An essential amino acid cannot be produced by the human body and as such must be take in from the environment through alternative sources (i.e) food. What do eukaryotic cell membranes have that prokaryotic cell membranes don't? - ANSWER-sterol lipids (ex: cholesterol) Functions of plasma membrane? - ANSWER-Proteins in membrane allow the import of nutrients or export of molecules (wastes, signaling molecules) Protein sensors receive information about the environment or messages from other cells Mechanical properties allow for movement, growth, and reseal
What are the three parts to a nucleotide? - ANSWER-sugar (DNA), phosphate, nitrogenous base What is the central dogma of biology? - ANSWER-DNA is transcribed into a strand of RNA that leaves the nucleus and is translated on ribosomes into proteins What does saturation refer to in fatty acids? - ANSWER-how many hydrogen are present in the hydrocarbons Where are ribosomes located? - ANSWER-in the cytoplasm of prokaryotic cells and in the ER of eukaryotic cells. What is cellular metabolism? - ANSWER-Metabolism is a controlled set of biochemical reactions that occur in living organisms in order to maintain life. What is the primary function of enzymes and how are they regulated? - ANSWER- Enzymes speed up chemical reactions. Most notably, the enzyme is not consumed during the reaction and can be used repeatedly by the cell. Enzymes can also be regulated by a cofactor such that in the absence of the proper cofactor, enzymes are inactive while in its presence enzymes are active. What is the difference between catabolism and anabolism? - ANSWER-Catabolism is the process of breaking down larger molecules into useful energy sources. release energy. whereas anabolism is the building up or biosynthesis of macromolecules from smaller molecular units into larger complexes. consumes energy what is the function of an enzyme dependent on? - ANSWER-its structure Can enzymes be reused? - ANSWER-yes What is the rate of reaction dependent on? - ANSWER-enzyme concentration, substrate concentration, temperature, pH What are the different classes of enzymes? - ANSWER-1. Oxidoreductases
What are the 3 ingredients needed to make ATP? - ANSWER-energy, carbon, electrons What are the 2 kinds of chemotrophs? - ANSWER-organotrophs and lithotrophs ATP has the energy to __________ while ADP has the capacity to ________ energy. - ANSWER-donate, accept Chemotrophs can be subdivided into what two additional subgroups? - ANSWER- organotrophs (removing electrons from organic molecules such as glucose) or lithotrophs, which remove electrons from inorganic molecules Chemotrophs utilize what form of phosphorylation? - ANSWER-oxidative phosphorylation What are the three distinct stages in catabolism of glucose? - ANSWER-Glycolysis, Kreb's Cycle, and Electron Transport Chain Where does glycolysis occur? - ANSWER-cytoplasm What are the products for glycolysis? - ANSWER-2 pyruvate, 2 NADH, 2 ATP What is glycolysis for cells that don't use oxygen? - ANSWER-fermentation What is the intermediate step of cellular respiration? - ANSWER-converting pyruvate into acetyl-coA Where does the Krebs cycle occur? - ANSWER-mitochondrial matrix What is the product of 2 turns around the Kreb's Cycle? - ANSWER-2 ATP, 6 NADH, 2 FADH Where does the electron transport chain occur? - ANSWER-mitochondrial membrane What is the end product of cellular respiration? - ANSWER-38 ATP What are the two main strategies for replenishing cellular concentrations of NAD+, and when these strategies be utilized? - ANSWER-reparation and fermentation Where does photosynthesis occur? - ANSWER-Chloroplast What processes is photosynthesis broken down into? - ANSWER-light and dark reactions What are the components of a nucleotide? - ANSWER-sugar, phosphate group, nitrogenous base
What is the difference in nitrogenous bases for DNA and RNA? - ANSWER-RNA uses uracil instead of cytosine Which monomer doesn't form a polymer? - ANSWER-lipids What is the difference between saturated and unsaturated fat? - ANSWER-saturated- come from animals, solid at room temp. every carbon has a hydrogen. What are other sources of energy apart from glucose? - ANSWER-proteins and lipids What determines the specificity of an enzyme? - ANSWER-the active site What is a cofactor? - ANSWER-A cofactor is a small chemical component that assists an enzyme during the catalysis reactions. A cofactor is usually metal ions. An organism that derives its energy by removing electrons from elemental sulfur would be classified as a __________? - ANSWER-lithotroph What is one of the main functions of light reactions? - ANSWER-Similar to the electron transport chain, one of its main functions is to generate a proton concentration gradient to generate ATP. How many turns (or repititions) of the Calvin Cycle are required to generate one molecule of glucose? - ANSWER- What unit of measurement is used to measure microscopy? - ANSWER-metric system Define micrometer and nanometer - ANSWER-A micrometer is the unit of measurement used to measure cells. It is one-millionth of a meter. A nanometer is the unit of measurement used to measure cell organelles and viruses. It is one-billionth of a meter. How is the total magnification of an object calculated? - ANSWER-total magnification is calculated by multiplying the power of the objective and the power of the eyepiece How does magnification work? - ANSWER-results when radiation (light) bends as it passes through a lens what 2 factors influence the ability to see an object? - ANSWER-resolution and contrast The closer 2 objects are to each other the ____ resolution requirement needs to be - ANSWER-greater What are the 3 types of microscopes used in labs? - ANSWER-light, electron, probe What are the types of light microscopes? - ANSWER--bright-field -dark-field
-phase-contrast -fluorescence -confocal Which microscope is used to view live structures and motility? - ANSWER-phase contrast What are the 2 types of electron microscopes? - ANSWER-transmission and scanning What are the benefits of staining? - ANSWER-increases contrast allows for viewing of shape, size, etc for higher magnifications, ____ light is needed - ANSWER-more How does a dark field microscope work? - ANSWER-reflects light off specimen at an angle What is chromophore? - ANSWER-colored ion in a dye What is the difference between acidic and basic dyes? - ANSWER-anionic (-) chromophores stain positively charged structures (low pH), cationic (+) chromophores stain negatively charged structures (high pH) most common What are examples of simple stains? - ANSWER-crystal violet, methylene blue, safranin what are examples of differential stains? - ANSWER-Acid-fast stain, Endospore stain, hematoxylin and Gram stain. Gram positive bacteria have a _____ peptidoglycan layer and gram negative bacteria have a ____ peptidoglycan layer - ANSWER-thick, thin What does a negative stain highlight? - ANSWER-bacterial capsule What is the acid-fast stain used for? - ANSWER-staining Mycobacterium and Nocardia What is the primary dye and counterstain for acid-fast staining? - ANSWER-primary- carbolfuchsin counterstain - methylene blue What does the Giemsa stain? - ANSWER-blood parasites What is the purpose of heat fixing a sample? - ANSWER-Heat fixing ensures the samples tightly adhere to the glass slide prior to staining (and washing) procedures. What is the primary purpose of a wet mount? - ANSWER-Wet mounts are most often performed to visualize live cells as well as the motility and behavior of an organism.
This type of microscope uses neither halogen nor UV light sources but rather lasers to illuminate stained cells in high resolution. - ANSWER-confocal What is the most common growth media? - ANSWER-LB media How does selective media restrict growth of certain microbes? - ANSWER-limiting amounts of nutrients, varying degrees of pH (being either very acidic or very basic media), or various chemical additives that limit unwanted microbial growth (i.e. antibiotics) What is a fastidious microorganism? - ANSWER-organisms with complex growth requirements such that if absent will not grow What is agar made of? - ANSWER-red algae ->seaweed What is a selective media? - ANSWER-Selective media allows for only the growth of certain microbes while restricting the growth of all others. What is a differential media? - ANSWER-Differential media is used to distinguish between two (or more) related microbes. What are the 3 forms of hemolysis found on blood agar plates? - ANSWER-Alpha (green), Beta (clear zones) and Gamma (white/tan). Microbes capable of alpha hemolysis present with greenish-brown color colonies due to the incomplete (partial) lysis of red blood cells. Beta hemolysis is classified as the capacity of a microbe to completely lyse red blood cells. The resulting lysis presents as a distinct zone of clearing around the growing colony. Gamma hemolysis designates the absence or lack of hemolytic activity and the resulting colonies are often white/tan in color growing on the red background color of the unaffected blood agar plate. What is the purpose of Columbia CNA agar? - ANSWER-grows gram-positive bacteria, restricts gram-negative What are the selective and differential abilities of a MacConkey agar plate? - ANSWER- MacConkey agar is selective in that only Gram-negative microbes will grow on the agar —Gram-positive microbes simply do not grow. MacConkey agar is also considered a differential media as it distinguishes between microbes capable of fermenting lactose (red colonies) and those that are non-fermenters (white/tan colonies). What color would E. coli be on an EMB plate? - ANSWER-metallic green What is the name of the process of spreading a bacterial culture onto a petri dish? - ANSWER-Culturing What is the purpose of a quadrant streak? - ANSWER-to obtain pure, isolated colonies
To be considered a pure culture, the sample (1) can be traced back to a single cell and (2)__________? - ANSWER-be free from external contaminants A dilution gradient is formed when carrying out what generalize plating strategy? - ANSWER-quadrant streak What is the difference between pathogenicity and virulence? - ANSWER-pathogenicity- ability of a microbe to cause disease (yes or no question) virulence- ease of pathogen to infect host and cause disease What are the 5 steps to infection? - ANSWER-1. enter the host
What are the characteristics of Tuberculosis? - ANSWER-bacillus shape, Gram +, nonmotile, catalase + What are the characteristics of leprosy? - ANSWER-bacillus shape, Gram-positive, acid fast stain needed. What are the 2 forms of leprosy? - ANSWER-tuberculoid and lepromatous What are the 4 types of Clostridium diseases? - ANSWER-botulism, tetanus, gas gangrene, C diff What is the concept of universal precautions? - ANSWER-Universal precautions means any and all samples, whether known or unknown, are to be treated as potentially hazardous (or pathogenic) materials. What would a researcher be certain to note while analyzing a microbial sample? - ANSWER-1. Size and shape2. Any observable motility3. Gram status (positive or negative)4. The presence of any chemical reactions5. Changes in color localized to the organism or the surrounding media6. Capture (or draw) images of any of the characteristics described above What disease can result if a patient with streptococcal pharyngitis goes untreated? - ANSWER-Rheumatic fever Streptococcus, E. coli, pseudomonas, and klebsiella are all capable of causing what disease? - ANSWER-Streptococcal septicemia What is a facultative anaerobe? - ANSWER-A facultative anaerobe is capable of growth under both aerobic (with oxygen) and anaerobic (in the absence of oxygen) condition. which mycobacterium infection will be treated free of charge by the World Health Organization (WHO)? - ANSWER-Leprosy is completely curable using a multiple-drug therapy regimen consisting of various combinations of the drugs dapsone, rifampin and clofazimine—all of which is given free of charge. What are the three main conditions caused by the botulism toxin? - ANSWER-infant botulism, food borne botulism, and wound botulism Why are infants (< 6 months) more susceptible to botulism? - ANSWER-Their immune systems haven't developed the proper microflora that older individuals have to fight off foodborne illnesses. What Gram-negative bacterium might you come into contact with in a unsanitary hot tub? - ANSWER-Legionella
What are the three forms of plague, and what regions do they affect? - ANSWER- Bubonic plague, Pneumonic plague, and Septicemic plague. Pneumonic plague affects the respiratory system (lungs). The most rare of all three plagues, septicemic plague targets the blood system and, if left untreated, will develop into a life-threatening illness as the blood-borne bacteria can infect all major organs. What are the 3 types of Anthrax? - ANSWER-cutaneous, gastrointestinal, , pulmonary Rheumatic fever displays ______ hemolytic activity and occurs when _______ is left untreated. - ANSWER-Beta; Strep. Pharyngitis When a bacterium neither harms nor benefits from the host from which it obtains nutrients, it is referred to as being ___________. - ANSWER-Commensal Directly ingesting clostridium or its associated spores will not cause illness in adults. - ANSWER-True There are currently no cures for tetanus - ANSWER-True Identify the medical condition characterized by robust carbohydrate fermentation under anaerobic conditions, swelling of the infected areas and fever. - ANSWER-Gas gangrene Bubonic plague is often characterized by painfully swollen lymph nodes. - ANSWER- True Which form of the plague is highly virulent? What does it target? - ANSWER-Pneumonic plague is highly virulent and targets the respiratory (lungs) system. Syphilis is caused by: - ANSWER-Gram-Negative spirochete How is syphilis best viewed? - ANSWER-dark field What are the 4 phases of syphilis? - ANSWER-primary, secondary, latent, tertiary Why aren't viruses alive? - ANSWER-cannot create their own components or carry out metabolism--> rely on host cells What kinds of cells can a virus infect? - ANSWER-all types of cells What are the 3 capsid shapes? - ANSWER-helical, icosahedral, complex What is a virion and what are its components and functions? - ANSWER-virion = capsid and its genetic material. it is a single viral particle.
What is the function of a viral capsid? - ANSWER-protein shell that protects viral genome What is a viral envelope? - ANSWER-What viruses surround themselves with that, on the outside resemble host own cells, and helps virus avoid detection by immune system. What is a virion with no viral envelope called? - ANSWER-naked virion How does a naked virion form? - ANSWER-lyses from cell What is a viral spike and it's function? - ANSWER-glycoprotein extension that helps identify and bind to host cell proteins What are the 6 steps to viral replication? - ANSWER-1. Attachment
release What are the steps for the lysogenic pathway? - ANSWER-integration cell division lytic cycle What is a prophage? - ANSWER-the viral DNA that is embedded in the host's DNA What is the viral load or viral titer? - ANSWER-the amount of viral particles present in a sample How do you measure turbidity? - ANSWER-high bacteria = high turbidity = very cloudy becomes clearer if phage lyses bacteria define lesion and rash - ANSWER-lesion - any observable change or abnormality rash- widespread outbreak of lesions what is a primary lesion? - ANSWER-associated with a specific disease What are the different types of vaccines? - ANSWER--live attenuated (active virus is weakened) -inactivated whole agent (entire dead pathogen is used) -inactivated subunit (portion of pathogen is used with adjuvant) What is the difference between the Salk and Sabin vaccines? - ANSWER-salk- injected vaccine, stable during transport sabin- oral vaccine, easy to administer, can result in herd immunity. What types of viruses are enveloped and which are not? - ANSWER-animal viruses - enveloped -plant or bacteria infecting - naked What type of microscope would be used to study the shape of a viral capsid? - ANSWER-electron What structural aspects make bacteriophages distinct from viruses that infect either animals or plants? - ANSWER-Bacteriophages possess an icosahedral capsid head group and a helical tail. Attached to the tail are fibrous extensions or 'legs' that aid in binding host cells. Notably, this particular structural arrangement has not been observed among viruses that infect either animals or plants. To what family of viruses does rubella come from and how is it transmitted? - ANSWER- Togaviridae. air-borne paricles
What is the common name for rubeola, and is it a DNA or RNA virus? - ANSWER- Measles and RNA What linear, double-stranded, enveloped DNA virus is the first virus (as of October 26,