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True/False. A virus is considered a microorganism. ✔✔False, Viruses are not living and as such are not considered microorganisms. Viruses can, however, be classified as microbes, a more general term that includes microorganisms and viruses. What is the smallest biological unit of life? ✔✔A cell What are the four main types of macromolecules found in cells? ✔✔Proteins, Lipids, Nucleic Acids, Carbohydrates Proteins are formed from various combinations of ✔✔Amino acids There are how many known forms of amino acids ✔✔twenty How many amino acids are classified as being essential amino acids? ✔✔Nine Where can the two major types of nucleic acids be found in the cell? ✔✔DNA, RNA. Found in the nucleus.
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What is the role of RNA? ✔✔RNA , found in the nucleus is capable of leaving the nucleus. RNA is repsponsible for deciphering the hereditary information in DNA and uses it to synthesize proteins. What is the role of DNA? ✔✔DNA, found in the nucleus contains vast amount of hereditary inforamtion, responible for inhereitable characteristic os living organisms. Complete the following RNA strand, and indicate how many bonds are formed for each complementary pair: 3' GGUCAUCG 5'5' CC AGC 3' ✔✔3' GGUCAUCG 5'5' CCAGUAGC 3'There are 2 bonds formed between A and U, and 3 bonds between G and C. The plasma membrane ✔✔Restricts movement of materials in and out of the cell & Prevents essential nutrients from escaping How many carbon atoms are present in glucose? ✔✔ 6 True of False: The genetic material within a prokaryotic cell is contained within a membrane- enclosed region. ✔✔False Only eukaryotic cells contain its genetic material within a nucleus. True or False: Prokaryotic cells can be subdivided into Bacteria and Archaea. ✔✔True
The combination of the cell membrane and the outer membrane is referred to as the ✔✔Cell envelope The function of the mitochondria is ✔✔To produce energy (ATP) True or False. All multicellular microorganisms classified as Animalia are autotropic. ✔✔False True or False: Metabolism is a controlled set of biochemical reactions that occur in living organisms in order to maintain life. ✔✔True True or False: Enzymes slow down chemical reactions to conserve energy. ✔✔False What is a cofactor? ✔✔A cofactor is a small chemical component that assists an enzyme during the catalysis reactions. A cofactor is usually metal ions. Define catabolism ✔✔Catabolism is the process of breaking down larger molecules into useful energy sources. In order to convert proteins into amino acids which metabolic process would be active? ✔✔Catabolism would be active as proteins are made up of amino acids. Therefore the process described (proteins into amino acids) is the breakdown, or catabolism of protein.
Describe the energy transfer process relative to both ATP and ADP. ✔✔ATP has the energy (phosphate group) to donate while ADP can accept energy in the form of a phosphate group. Thus, ATP can be reduced (ATP ⟶⟶ADP + Pi) while ADP can be built into ATP (ADP + Pi ⟶⟶ATP). From what source do chemotrophs acquire energy? ✔✔Chemotrophs acquire energy from preformed chemicals found in the environment. An organism that obtains its source of carbon from inorganic molecules such as carbon dioxide is referred to as a? ✔✔Autotroph This phosphorylation process occurs in the mitochondria of chemotropic eukaryotes. ✔✔Oxidative phosphorylation The catabolism of a single molecule of glucose goes through what 3 distinct transitions? ✔✔The breakdown of glucose goes through (1) Glycolysis then (2) Fermentation or Respiration and finally through (3) the electron transport chain (ETC). What is the most energetic transition in the catabolism of glucose? ✔✔The electron transport chain yields 34 ATP while both glycolysis and fermentation (or respiration) each yield only 2 ATP.
For the catabolism of proteins and lipids, which of the following enzymes are used? Select all that apply. ✔✔Proteases, Lipases True or False. The β-oxidation pathway catabolizes the fatty acid chains of lipids. ✔✔True Describe the relationship between chloroplasts and chlorophyll. ✔✔Both chloroplasts and chlorophyll are associated with photosynthesis. Chloroplasts are the double membrane-enclosed organelles that contain the photosynthetic pigment chlorophyll. True or False: Chloroplasts are specific to algae and plants. ✔✔True The process of carbon fixation begins with which of the following reactants: select all that apply. ✔✔CO2, H2O, ATP, NADPH What is one of the main functions of light reactions? ✔✔Similar to the electron transport chain, one of its main functions is to generate a proton concentration gradient to generate ATP. True or False: The Calvin cycle must occur in the absence of light. ✔✔False, dark reactions do not actually require darkness in order to occur. How many turns (or repititions) of the Calvin Cycle are required to generate one molecule of glucose? ✔✔ 6
[answer1]CO2 + [answer2]ATP + [answer3]NADPH + [answer4] H20 → C6H12O6 + [answer5]ADP + [answer6] NADP+ ✔✔6, 18, 12, 12, ---- > 18, 12 A micrometer is defined as: ✔✔ 10 - 6 Resolution is a factor that influence your ability to see an object. Explain ✔✔Resolution refers to the distance between two objects at which the objects still can be seen as separate. Poor or low resolution means two (or more) objects may appear as one. Contrast is a critical factor that influence your ability to see an object. Explain ✔✔Contrast is the difference in light absorbance between two objects. Poor contrast gives a high background and makes the visualization of multiple objects difficult. Assuming a fixed ocular, identify the part of the microscope you would adjust to enhance the magnification of a sample. ✔✔Objective What is the total magnification (relative to your eye) of a sample imaged with a 60x objective and a 10x eyepiece? Show your math. ✔✔The total magnification is (objective x eyepiece)= Total magnification: 60 x 10 = 600x magnification
Gram-Positive cells appear [answer1] in color due to a [answer2] peptidoglycan layer in the cell wall. ✔✔1. Purple
- Thick Gram-Negative cells appear [answer1] in color due to a [answer2] peptidoglycan layer in the cell wall. ✔✔1. Pink
- Thin True or False: Following the decolorization step of the Gram stain, Gram-Negative bacteria will appear colorless. ✔✔True, Even together, the LPS and thin peptidoglycan layer are unable to retain the crystal violet dye during decolorization. True or False: If you wish to study the motility of an organism you cannot heat fix, but you can chemically fix the specimen. ✔✔False Both heat and chemical fixation strategies will kill the cell, making motility observations impossible. You want to observe the size and shape of a cell. What is the easiest staining technique that you could perform? Name at least one dye you would use during this process. ✔✔Simple stain. You could use any of the following: methylene blue, crystal violet, safranin or fuschin. You suspect a patient may have TB. Once a sample has been obtained, it is sent off to the lab for an acid-fast stain. If the patient were infected with TB, describe what you would expect to see on
the stained slide. ✔✔You would expect to see red cells (TB+) on a blue background (TB negative). True or False: If a patient is suspected of having malaria, a Giemsa stain would be an appropriate differential test to perform. ✔✔True Giemsa stains are often used in the clinical setting to aid in the diagnosis of blood parasites. What does the TEM microscope show? ✔✔Transmission Electron Microscope (TEM). Even at 20nm resolution (inset image), subcellular substructures are still visible. A gram stain has been attempted on an unknown sample, and it was found to have a high degree of resistance to decolorization. Given this property, which stain should be attempted next? ✔✔Acid-fast staining A fluorescence microscope shows ✔✔Dark background and fluorescense bacteria (lime green) A slide stained with methylene blue simple stain to observe cellular morphology ✔✔Bright field The gliding motility of a living cyanobacteria ✔✔Phase contrast An unstained sample that cannot be visualized with bright field because microorganism absorbs very little light ✔✔Dark field
What is agar used for in microbiology? ✔✔Agar is used to create a solid, smooth surface on which microbes can grow. Blood agar is which type of medium? Select all that apply. ✔✔Differential, Enriched Alpha hemolysis has... ✔✔Incomplete Hemolitic activity Beta Hemolysis has... ✔✔Complete hemolitic activity Gamma Hemolysis has... ✔✔No hemolitic activities Columbia CNA agar is used to isolate ✔✔Gram-Positive True or False: Chocolate agar gets its brown color from cocoa to produce an enriched media. ✔✔False Chocolate (cocoa) is never added to the media. The name is derived simply based on the color that actually comes from the presence of 'cooked' (lysed) red blood cells in the media. When e.coli is on a MacConkey agar plate, is a gram stain necessary to confirm if E.coli is gram- neg or gram-pos? ✔✔No. A Gram stain would not be necessary, as only Gram-Negative microbes will grow on MacConkey agar. Thus, E. coli is a Gram-Negative microbe.
In an attempt to detect the presence of the pathogenic strain of E. coli O157:H7, a researcher spread a culture onto a MacConkey agar with failed results. What type of agar should they (correctly) try next? Why? ✔✔The microbe should be plated on SMAC (Sorbitol-MacConkey agar) as it is specifically formulated to detect O157:H7. Pathogenic E. coli (O157:H7) cannot ferment sorbitol while non-pathogenic E. coli can ferment both soribitol and lactose. In Eosin Methylene Blue (EMB) agar, what color indicates the presence of E. coli? ✔✔Metallic Green Which type of agar media is best suited to support the growth of Staphylococcus? ✔✔Mannitol salt agar What is the process of spreading a bacterial culture onto a petri dish called? ✔✔Plating In order to visual individual colonies of bacteria would you culture your sample in a liquid media or on a solid (agar) media? Why? ✔✔Solid (agar) media. The primary advantage is that cells are held into place. When grown in a nutrient broth, bacterial cells can multiply but are free to move around in solution. When grown on agar within a petri dish the fixed in such as way as to form colonies. True or False: The visualization of colonies on a petri dish represents bacterial cells that have multiplied ~2-3 times. ✔✔False
acceptable in practice provided the resulting gradient contains within it the growth of individual colonies—if not, the experiment must be repeated. True or False. Pathogenic strains of bacteria tend to grow slower than normal non-pathogenic bacterial strains. ✔✔False Pathogenic strains of bacteria tend to grow faster than non-pathogenic strains at 37°C, which is why researchers may set incubators at 25°C to restrict its growth. When given an unknown bacterial sample the first step is to expand the current bacterial population. Which form of media best suites this need? Why? MSA agar LB media MacConkey agar Columbia CNA agar ✔✔LB media. All other options (A, C and D) are all forms of selective media, meaning they may potentially inhibit the growth of the unknown sample. The concept of treating all samples, whether known or unknown, as potentially hazardous (or pathogenic) materials is known as. ✔✔Universal precautions List at least 3 observations a researcher would be sure to note while assessing an unknown microbial sample. ✔✔Size, shape, color, chemical reactions, image of the sample, gram staining (neg or positve)
While observing an unknown sample of limited amounts, a researcher must determine the following observations: (1) the presence of any motility and (2) its Gram status using the same sample—the liquid sample cannot be divided. Which would you determine first and why? ✔✔You must determine motility before determining the Gram status. Motility requires a wet mount, while Gram staining requires heat fixing the sample. A facultative anaerobe is a microorganism capable of growth under what conditions? ✔✔A facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic (without oxygen) conditions. As Streptococcus is catalase negative would it thrive or die in the presence of peroxides? Why? ✔✔Streptococcus would not survive in the presence of peroxides—it is unable to breakdown peroxides (catalase negative). Streptococcus is most often streaked onto ✔✔Blood agar True or False. The Lancefield groups are used to subdivide antigenic groups of gamma- hemolytic Streptococcus. ✔✔False The Lancefield groupings are used to subdivide beta-hemolytic Strep. Greater than 90% of all human streptococcal infections belong to: ✔✔Group A
Pus-filled lesions on skin or hair ✔✔folliculitis Ruptured pustules; treated with Penicillin ✔✔scalded-skin syndrome True or False. Staphylococcus is the only causative agent of conjunctivitis. ✔✔False True or False. Tuberculosis is best identified by a Gram stain. ✔✔False True or False. Although TB must be inhaled and reside in the lung in order to cause infection, TB can also spread to the brain, spine, and kidneys. ✔✔True TB can move systemically through the blood to infect other areas (brain, spine and kidney). However, when located outside of the lung, TB tends to be non-infectious. Identify the disease: It is a small, acid-fast rod usually remaining asymptomatic for up to 20 years. It affects the skin, nerves, upper respiratory tract, and eyes of infected individuals. ✔✔Hansen's disease, Leprosy True or False. Only directly ingesting the pre-formed clostridium toxin (neither the bacteria nor its spores) will cause disease in adults. ✔✔False
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 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 True or False. There are currently no cures for tetanus. ✔✔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 under anaerobic conditions, swelling of the infected areas and fever. ✔✔Gas gangrene. The key identifier here is the robust carbohydrate fermentation, which manifests as intense gas production and swelling—both trademark conditions of gas gangrene. The alpha-toxin perfringolysin is associated with which medical condition caused by Gram- positive anaerobic bacteria? ✔✔Gas gangrene 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? ✔✔Legionnaires. Legionella can only be transmitted through droplets small enough to be breathed in. True or False. Bubonic plague is often characterized by painfully swollen lymph nodes. ✔✔true
