Biod171 Microbiology Exam Questions With Verified Correct Answers || Graded A+ Updated

BIOD171 Microbiology EXAM QUESTIONS WITH VERIFIED CORRECT ANSWERS || GRADED A+ UPDATED While visiting his grandparents, a 10-year-old child has green beans for dinner that were harvested from his grandparents' garden and canned the previous year. Severe illness sets in and the child is taken to the hospital. Botulism is suspected, but what form - foodborne, infant, or wound botulism? Explain why it would NOT be classified as the other two options. - ANSWER Foodborne botulism. The child is too old ( 6 months) to be considered for infant botulism and wounds were not present. The green beans were likely improperly canned and under the low-acidic, anaerobic conditions, bacterial growth was encouraged. True or False. There are currently no cures for tetanus. - ANSWER True; Although the symptoms can be treated it is only to manage the discomfort not to cure. Identify the medical condition characterized by robust carbohydrate fermentation, swelling of the infected areas, and fever. Explain why hyperbaric oxygen therapy is a possible treatment. - ANSWER Gas gangrene, because C. perfringens is an anaerobic bacteria Why does the alpha toxin (perfringolysin) produced during an infection of gas gangrene cause cell death? - ANSWER The toxin perforates the membrane. It forms pores in the plasma membrane of host cells resulting in uncontrolled ion fluxes and eventually cell lysis and death. You develop a fever, chills, and pneumonia after recently using a warm midst vaporizer in an attempt to open your sinuses. What bacterial disease would a doctor suspect is causing your symptoms? Would the doctor suspect you contracted it from touching (potentially) contaminated doorknobs? - ANSWER Legionnaires. No—legionella cannot be spread simply by direct contact between people. Legionella can only be transmitted through droplets small enough to be breathed in. True or False. Pneumonic plague is often characterized by painfully swollen lymph nodes. - ANSWER False; Pneumonic plague targets the respiratory system while bubonic targets the lymph system. Which form of the plague is highly virulent? What does it target? - ANSWER Pneumonic plague is highly virulent and targets the respiratory (lungs) system. Identify the following disease: - ANSWER Anthrax—the distinct black center at the site of infection is a hallmark of anthrax infection. Syphilis is caused by: - ANSWER Gram-Negative spirochete True or False. Chlyamida is an obligate parasite and as such can be grown on agar plates alone. - ANSWER False; An obligate parasite requires a host (viable cells) to be present for its growth. Match the following diseases with their respective symptoms if left untreated: 1. Gonorrhea 2. syphilis 3. chlamydia A. Paralysis, blindness and dementia B. Painfully swollen lymph nodes C. Cardiac and neurological complications D. Respiratory failure associated with lock-jaw E. Infertility and pelvic inflammatory disease. F. Sore throat, ocular discharge and fever - ANSWER 1. Gonorrhea - Cardiac and neurological complications 2. syphilis- A. Paralysis, blindness and dementia 3. chlamydia- E. Infertility and pelvic inflammatory disease. phase contrast microscope - ANSWER - distinct advantage over brightfield microscope - can provide detailed images of live cells without staining - by using specialized condensers & objectives, amplifies the slight differences between cells and the surrounding medium (background) to make the cells highly distinguishable - can be used to visualize cell movements (motility), such as swimming or gliding, without altering the cell morphology commonly brought about from treating the cells with a fixing agent Note: although able to see the cell in great detail, scientists often still use organelle specific dyes to highlight a particular region of the cell. ie: although the cell membrane, nucleus, and other organelles are readily apparent, a researcher interested in the trans-Golgi (TGN) region may still add a dye that specifically binds within the TGN just to make it more prominent in the final acquired image phase contrast microscope - ANSWER noticeable detail & depth achieved whereas it would normally be invisible dark field microscope - ANSWER - used to greatly increase contrast between specimen & background, resulting in a dark background w/ bright objects in it Scanning transmission electron holography microscopes (STEHM) - ANSWER also uses electron beam but. coupled w/ holography technique to study surfaces of proteins and subcellular structures has the capacity to magnify subatomic structure ip to 20million time larger than what can be view w the naked eye while EM can resolve 1nm, STEHM has capacity ro resolve 35 pm (picometer is trillionth of a meter or 10^-12) picometer - ANSWER one trillionth of a meter 10^-12 nanometer - ANSWER one billionth of a meter 10^-9 micrometer - ANSWER one millionth of a meter 10^-6 stains - ANSWER can be used to examine - tissues (muscle or connective) - specific types of cells (blood, bacterial, etc.) - even organelles within an individual cell (nucleus, ER, etc.) we will focus on both prokaryotic and eukaryotic microorganisms, their identifying traits, and the associated clinical implications - ANSWER stains - ANSWER are salts, which break down positively & negatively charges ions chromophore - ANSWER colored ion in the dye Acidic dyes (Na+Dye-) - ANSWER Anionic (-) chromophores that stain positively charged structures in acidic conditions (low pH) - mostly used for "negative staining" Basic Dyes (Dye+Cl-) - ANSWER Cationic (+) chromophores that stain negatively charged structures in basic conditions (high pH) -most common simple stain - ANSWER cell size, shape and arrangement simple stain - ANSWER single basic dye, soak in dye for 30-60 sec and rinsing ex. crystal violet, safranin, fuchsin or methylene blue differential stain - ANSWER at least 2 dyes are used to show different cells, structures or chemicals in a sample and is a multistep process ex. gram, acid-fast, endospore, hematoxylin and eosin staining special stains - ANSWER simple stains that visualize specific structures ex. negative stains, flaggelar stains and fluorescent stains gram staining - ANSWER - a form of differential stains - takes advantages of differences in the bacteria cell wall - divides bacteria into 2 groups - gram postive bacteria = thick peptidoglycan layer - gram negative bacteria= thin peptidoglycan layer, outer membrane - one of the first testsvdone in identiftiy an unknown pathogen Steps to Gram Stain; Step 1 - ANSWER 1. Sample smeared on slide, slide is fixed. The slide is flooded w/ crystal violet (primary stain) for 1 min. Then rinsed w/ water Results: all cells are stained purple going to stick to thick pepto wall (gram positive) Steps to Gram Stain: Step 2 - ANSWER 2. Slide is flooded w iodine for 1 min, bind and make stable complex w Crystal violet. Results: idione acts as mordant, all cells remain purple Steps for Gram Staining: Step 3 - ANSWER 3. decolorizing step slide is rinsed w solution of ethanol & acetone for 10-30sec, then rinsed w water. Results: breaks down thin pep wall, so any dye that was traped, washes away. smear is colorless, gram-negative. colorless cells hard to visuilze. cells remain purple, gram-postive Steps for Gram Staining: Step 4 - ANSWER 4. 2nd dye is used. red dye, safranin floods slide for 1 min and is rinsed w water and blotted dry. safrain is counter stain. Result: gram-postive cells remain purple gram-negative cells turn pink gram-postive - ANSWER purple thick peptidoglycan layer layer is not impereable, select molecules can still pass through Crystal violet is retained by the thick peptidoglycan cell wall and forms a stable complex with iodine thick peptidoglycan layer - ANSWER provides vital protective later to surrounding environment gram negative - ANSWER pink, thin peptidoglycan layer & outer membrane disadvantages of gram stain - ANSWER requirment of the cells to be fixed to glass slide tightly adhered cells are required to prevent sampel loss during the staining/washing steps fixation kills the microorganism, charaterstis of motility are not possible heat fixation - ANSWER most common method of fixation samples added to glass slide, then passed through a flame until all liquid in the sample has been removed chemical fixation - ANSWER use of paraformaldehyde, ethanol, or methanol Catabolism - ANSWER The process of breaking down larger molecules into useful energy sources Anabolism - ANSWER The building up or biosynthesis of macromolecules from smaller molecular units into larger complexes ATP and ADP - ANSWER ATP has energy to donate, while ADP can accept energy (phosphate group) to become ATP. By donating available phosphate groups, ATP transfers energy from catabolic (breaking down) reactions to be used for anabolism (building up). This process of donating and/or accepting energy is what fuels a cell to carry out the necessary biochemical reactions for survival. Phototrophs - ANSWER Acquire energy from photons of light to generate ATP from ADP Chemotrophs - ANSWER Acquire energy from preformed (already existing) chemicals found in the environment Organotrophs - ANSWER Remove electrons from organic molecules (such as glucose) Lithotrophs - ANSWER Remove electrons from inorganic molecules (such as elemental sulfur) Heterotroph - ANSWER A microorganism that derives its carbon from organic molecules, such as sugars Autotrophs - ANSWER Organisms that de