Bio 242 Midterm Review 2022

What are the characteristics of parasites? - ANSWER -live inside or outside the living host -need nutrients & protection -produce some degree of harm to the host Describe what Pasteur did in his spontaneous generation experiment. - ANSWER -two swan-naked flasks (open-end tube) -heated the broth in the two flasks (microbes died in broth) - broke one neck of the flask (there microbes growing in the broth) -other neck of the flask, he did not break the neck (no microbes that grew in the broth) What types of diseases can Koch's postulates be used or applied? - ANSWER -two swan-naked flasks (open-end tube) -heated the broth in the two flasks (microbes died in broth) - broke one neck of the flask (there microbes growing in the broth) -other neck of the flask, he did not break the neck (no microbes that grew in the broth) What types of diseases can Koch's postulates be used or applied? - ANSWER - Based on the germ theory of disease (pathogenic organisms can cause diseases) - examples: tuberculosis, leprosy, diarrhea by amoeba, anthrax - Whether the microbe is pathogenic and which disease is caused - Opposing examples: diabetes, hypertension, cancer (genetic) · What makes viruses different from living organisms? - ANSWER - Acellular (made up of cells), do not resemble cells - Cannot synthesize proteins - not independent - no membrane-bound organelles - can only replicate in a living host - intracellular parasites - have external coating & a core nucleic acid (sometimes with an envelope) - sometimes with one or two enzymes What are the components of the cell membrane? - ANSWER - Phospholipids - Sterols - Proteins Give examples of organisms that have mycolic acid in their cell wall. - ANSWER - Mycobacterium - Nocardia · What organisms can alcohol-based sanitizers be effectively used against? - ANSWER - Gram (-) bacteria; other microbes that have lipids in the cell membrane · Differentiate the types of RNA (rRNA, tRNA, mRNA). - ANSWER - rRNA composes the ribosomes - tRNA brings in the correct amino acids for protein assembly - mRNA is a copy of a gene that provides the order & type of amino acids in a protein What types of mutations can lead to frameshift? - ANSWER - Deletion & insertion What is gene therapy? - ANSWER - Introduction of normal functional genes into people with genetic diseases Selective Media - ANSWER - Selective: with agents inhibit growth of other microbes; provides growth to a specific microbe; isolate a microbe using selective media What is inoculation? - ANSWER - To introduce a microbe into a culture media (as inoculum) to grow or cultivate the microbe Differentiate bright-field, dark-field, phase-contrast, fluorescence, & electron microscopes in terms of resolution & magnification. - ANSWER - Highest magnification and best resolution = electron microscopes Differential - ANSWER - allows multiple microbes to grow but shows the differences between them (shape of the colony, color of the colony) Enriched - ANSWER - grow wide variety of microbes; contain complex organic substances, such as blood, serum, or special growth factors (vitamins, minerals, etc.) Photoheterotroph - ANSWER - rely on sunlight for energy & carbon from organic substances; in the absence of sunlight, they use organic substances as energy source and carbon source Photoautotroph - ANSWER - dependent on sunlight for energy & CO2 as carbon source Chemoautotroph - ANSWER - simple inorganic chemical substances for energy & CO2 for carbon source Lithotroph - ANSWER - rely only on inorganic substances Psychotrophs - ANSWER - 15 to 30 degree Celsius Mesophiles - ANSWER - 10 to 50 degree Celsius Thermophiles - ANSWER - 45 to 80 degrees Celsius Psychrophile - ANSWER - below 15 degrees Celsius What is generation time? - ANSWER - Time required for cells to double (doubling time); a complete fission cycle - from parent cell to two new daughter cells Lag phase - ANSWER flat period; no growth; cells are metabolically active Exponential growth phase - ANSWER - (log phase) population increases geometrically Stationary growth phase - ANSWER - growth & death at the same rate; population is in survival mode Death phase - ANSWER - more cells die; use up all nutrients Exoenzymes - ANSWER - Exoenzymes: made inside the cells & sent out or transported out of the cells (digest nutrients, host tissue cells, etc.) Endoenzymes: - ANSWER - made and used or function inside the cells Glycolysis - ANSWER - 4 ATPs but 2 ATPs are used up; 2 NADH molecules Kreb's cycle - ANSWER - each pyruvic acid molecule generates 3 NADH (total of 6 NADH) Water production occurs in which part of aerobic respiration? - ANSWER - Electron transport chain/system (terminal step of aerobic respiration wherein hydrogen atoms react with oxygen to form water) · Describe anaerobic respiration. - ANSWER - Uses organic substances, not oxygen as final electron acceptor - Involves glycolysis to generate ATP, uses other substances as final electron acceptor What are the types of reproduction in protozoa, especially Plasmodium? - ANSWER - All protozoa reproduce by asexual means; some undergo multiple fission or schizogony Interphase - ANSWER -cell grows, DNA is replicated as well as other organelles Prophase - ANSWER - chromosomes form from the chromatin (threadlike); nucleus & nuclear envelope disappear Metaphase - ANSWER - chromosomes line up at the center of the cell Anaphase - ANSWER - sister chromatids are pulled away from each other to opposite poles Telophase - ANSWER cleavage furrow forms that divides the cell into two daughter cells; the nucleus and nuclear envelope re-form; chromosomes become thinner (chromatin) Describe helminth infection in humans. - ANSWER - Through the GI tract; ingestion · What types of reproduction do fungi, protozoa, & algae have? - ANSWER - Asexual and sexual · What are the parts & components of viruses? - ANSWER - Capsid: protein shell that surrounds the nucleic acid (RNA or DNA but not both) in the central core - Envelope: modified piece of host's cell membrane What is a temperate phage? - ANSWER - Enters an inactive prophage state while at the same time, inserts into the bacterial chromosome Prions - ANSWER - cytopathic proteins Phages - ANSWER - are viruses that parasitize a specific bacteria Viroids - ANSWER - infectious agents that lack a capsid; attack plants Disinfection: - ANSWER - destroys most pathogenic nonsporulating microbes or their toxins, usually on inanimate objects Degermation - ANSWER - physical removal of the microbes, surface oil, debris, soil from the skin to reduce microbial load Antisepsis - ANSWER - chemical treatment that completely removes or destroys all vegetative microbes on body surfaces Sanitization - ANSWER - cleaning an inanimate object using soap & degerming agents Sterilization - ANSWER - any process that completely removes or destroys all viable microbes, including viruses What is pressure-temperature sterilization? What laboratory equipment is used for pressure-temperature sterilization. - ANSWER - Autoclave; steam under pressure; 15 psi and 121 degrees Celsius Autoclave - ANSWER - uses steam under pressure; temperature and pressure are directly proportional Oven - ANSWER - uses dry heat, materials are sterilized at high temperatures; 150 to 180 degrees Celsius in 2 to 4 hours · What drug is used to treat tuberculosis? - ANSWER - isoniazid Make a list of the cellular basis for bacterial resistance to antimicrobials. - ANSWER - Mutation - Alter drug receptors - Prevent the entry of drugs into cells - Synthesize enzymes that alter drug structures How does a newborn get inoculated with normal microbiota? - ANSWER - Birth canal - Placenta - Breast milk - Diet - Through the hospital staff - Vaginal smear - Bottle feeding What is the most common entry route of pathogens in the body? - ANSWER - Respiratory tract · Describe the outer membrane of Gram-negative microbes. - ANSWER - Uppermost layer has lipopolysaccharide with a lipid portion called endotoxin (stimulates fever & other reactions) Fomite - ANSWER - inanimate object that harbors & transmits pathogens Carrier - ANSWER - anyone who harbors infections & spreads it Vector - ANSWER - transports & plays a role in the life cycle of a microbe Source - ANSWER - person or item from which an infection is directly acquired Reservoir - ANSWER - natural host or habitat of a pathogen Endemic - ANSWER - disease prevails continuously in a geographic region Epidemic - ANSWER - sudden outbreak or increase in number of disease cases in a community Pandemic - ANSWER - a disease afflicting an increase of the population worldwide or over a wide geographic area Sporadic - ANSWER - disease exhibits new cases at irregular intervals in unpredictable geographic regions · What organelles and cell components differentiate these organisms: Gram negative, protozoa, archaea, Gram positive, & Mycobacterium? - ANSWER - Mycobacterium has outer mycolic acid. - Gram positive bacteria have thick peptidoglycan in the cell wall - Gram negative bacteria have thin peptidoglycan layer in cells & outer lipopolysaccharide - Protozoans have organelles. Localized infection - ANSWER - infection is confined in one area Focal Infection - ANSWER - infectious agents break loose from a localized infection & carried by the circulation to other tissues Chronic Infection - ANSWER - diseases persist over a long duration Systemic Infection - ANSWER - infection has invaded many parts & organs via the circulation Secondary Infection - ANSWER - an infection is compounded by a preexisting infection What are the types of eukaryotic reproduction? - ANSWER - Schizogony, budding, spore formation, sexual, binary fission (in amoeba & paramecium) Make a list of the different strategies or ways by which microorganisms acquire antibiotic resistance. - ANSWER - Drug inactivation, efflux pump (pump out the drug), spontaneous mutation, horizontal gene transfer What are Koch's postulates? - ANSWER - The microbe or pathogen must be present in all cases of the disease - Pathogen can be isolated from the diseased host and grown in pure culture - Pathogen from the pure culture must cause the disease when inoculated into a healthy, susceptible laboratory animal - Pathogen must be re-isolated from the new host and shown to be the same as the originally inoculated pathogen Describe the contributions of Antoni Van Leuwenhoek - ANSWER - Invented the microscope - Saw "animalcules" - tiny microbes he saw under the microscope from pond water, rainwater, human mouth & intestine - Calculated the sizes of the microbes - Opposed spontaneous generation Describe the contributions of Louis Pasteur - ANSWER - Discovered fermentation - Coined the terms aerobic and anaerobic - Discovered vaccines against anthrax and rabies - Disproved spontaneous generation Aerobic respiration: - ANSWER - need oxygen; produces water, CO2, NADH, FADH2, ATP (36 to 40 ATPs); cellular respiration (glycolysis occurs in the cytoplasm while Kreb's cycle occurs in the mitochondrion); dependent on organic matter (specifically glucose that is broken down in glycolysis); ETC occurs in the mitochondria (or in the inner membrane); uses oxygen as final electron acceptor Fermentation - ANSWER - anaerobic (no oxygen needed); glycolysis breaks down glucose; ATP production (fewer ATPs),NADH is generated; uses other substances as final electron acceptor (not oxygen); produce lactic acid or alcohol, CO2; no Kreb's cycle, no ETC What are the nutritional and physical requirements of aerobic organisms that also thrive in acidic volcanic soil? - ANSWER - Thermophile: 50 to 60 degrees Celsius - Hyperthermophile: 80 degrees Celsius and up - Acidophiles: 0.1 to 5.4 pH - Carbon, nitrogen, sulfur, phosphorus, protein, potassium, magnesium, calcium, trace elements; oxygen (aerobic) Extracellular viruses - ANSWER - are virions that live outside the host; have a small amount of RNA or DNA (not both); as a virus particle; wrapped in a protein covering (capsid), sometimes in a protein-containing lipid membrane (envelope) Intracellular viruses - ANSWER - inside the host cell, only genetic material that influences the host's DNA; completely dependent on the host for survival, reproduction, and dispersal Virions - ANSWER infective stage of the virus outside the host cell, have core RNA or DNA and a capsid Prions - ANSWER - protein particles (no nucleic acid) are highly resistant to destruction Viroids - ANSWER - infectious particles that affect plants, smaller than a virus and consist only of nucleic acid without a protein coat