BIOD 171 ESSENTIAL MICROBIOLOGY FINAL EXAM 183 PRACTICE QUESTIONS AND ANSWERS 2023-2024
What various functions do proteins have in a cell
Proteins may
... [Show More] facilitate the movement of materials in or out of a cell.
Some can act as enzymes that catalyze, or speed up, biochemical processes. Others play a structural role while other proteins, such as filaments, enable movement.
What are the main morphologies of bacteria?
Bacteria can be described as coccus (round/spherical), bacillus (rod),
vibrio (curved rod)
spirillum (spiral/corkscrew).
What are the 4 main classifications of Eukarya
Animalia, Plantae, Fungi or Protista
What are the primary cellular organelles described in this module? Be sure to know the roles of each.
Ribosomes (protein synthesis) ER (site of protein synthesis)
Golgi (protein modification and distribution) lysosomes (waste disposal), mitochondria (ATP generation)
chloroplasts (plants only; site of photosynthesis).
True or False: Enzymes are polysaccharides that catalyze chemical reactions.
False. Enzymes are proteins
What are usually metal ions known to assists enzyme during the catalysis reaction?
Cofactors
Define catabolism
the breakdown of complex molecules in living organisms, release of energy
Upon cellular injury, which metabolic process is involved during the growth and repair phases of the cell?
The anabolic process would be active as it is involved in the building up of small complexes into larger complexes.
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).
An organism that derives its energy (generates ATP) from photons of light is called a
Phototrophic microorganism.
An organism that derives its energy by removing electrons from elemental sulfur would be classified as a ?
Lithotroph
A reactive intermediate would be present in which phosphorylation process?
The chemical compound losing the phosphate group is referred to as the phosphorylated reactive intermediate.
What is the primary byproduct of the TCA cycle?
NADH and FADH2
True or False. The reactants of the TCA cycle directly enter and fuel the electron transport system.
False.
True or False. The β-oxidation pathway catabolizes the fatty acid chains of lipids.
True
The process of carbon fixation begins with which of the following reactants: select all that apply.
A. ATP B. Glyceraldehyde-3-phosphate C. CO2 D. NADPH E. H2O
A, C, D, and E. Carbon fixation uses the ATP/NADPH produced during light reactions to convert CO2 and H2O into useful sources of energy (carbohydrates).
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: Dark reactions can occur in the presence or absence of light.
True.
How many turns (or repititions) of the Calvin Cycle are required to generate one molecule of glucose?
6
Complete the following equation by placing the appropriate numbers where indicated.
CO2 + ATP + NADPH + H20 → C6H12O6 + ADP + NADP+ 6 CO2 + 18 ATP + 12 NADPH + 12 H20 → C6H12O6 + 18 ADP + 12 NADP+
Match the following reactions to its corresponding enzyme:
1. A + B → A-B
2. A-B → A + B
3. A- + B →A + B-
4. Ab + C → A + Cb A- Lyases
B- Transferases
C- Oxioreductaces
D- Hydrolases
E- Ligases
F- Isomerases
1E 1. A + B → A-B Ligases 2A 2. A-B → A + B Lyases
3C 3. A— + B → A + B— Oxioreductaces
4B 4. Ab + C → A + Cb Transferases
A micrometer is defined as
10-6 (one millionth of a meter)
True or False: A nanometer is longer than a micrometer.
False. A nanometer is 1,000 times smaller than a micrometer.
Resolution and contrast are two critical factors that influence your ability to see an object. Explain each.
Resolution refers to the distance between two objects at which the objects still can be seen as separate. Poor or low resolution means objects may appear as one.
Contrast is the difference in light absorbance between two objects. Poor contrast gives a high background and makes the visualization of multiple objects difficult.
What is the total magnification (relative to your eye) of a sample imaged with a 20x objective and a 15x eyepiece? Show your math.
20 x 15 = 300x magnification
True or False: A cell that is adherent, flat (thin) and unstained is easily identified using bright field microscopy.
False.
Which of the following could be seen clearly by the unaided eye? Select all that apply. A. Bacteria with diameter of 24 μm B. Protozoa with diameter of 150 μm
C. Virus with a diameter of 0.2 μm D. Skin cell with diameter of 1500 μm
B and D. The unaided eye can, on average, clearly resolve objects > 100 μm
This type of microscope can provide detailed images of live cells without staining.
Phase-Contrast
This type of microscope is used to greatly increase the contrast between samples and background by reflecting light off of the specimen.
Dark Field
This type of microscope is capable of capturing images in multiple focal planes, rendering a specimen in 3D
Confocal
Gram-Positive cells appear in color due to a peptidoglycan layer in the cell wall.
Purple; Thick
Gram-Negative cells appear in color due to a peptidoglycan layer in the cell wall.
Pink; Thin
True or False: Following the decolorization step of the Gram stain, Gram- Negative bacteria will appear colorless.
True.
Name one substance capable of chemically fixing cells to a slide.
Ethanol
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 via 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.
The distinctions for Lancefield subgroupings lie in its: (
Carbohydrate composition of antigens
True or False: Growth media is best suited for distinguishing between two similar species of bacteria.
False
A researcher is asked to determine which of two vials contains E coli and which contains Salmonella. Knowing both are Gram-Negative while only one of them is capable of fermenting lactose, which type of media would be best suited?
Differential media
What are the requirements of a fastidious microbe?
Enriched medias, as a fastidious microbe is an organism with complex growth requirements such that if absent it will not grow.
True or False: LB agar is classified as a non-selective, non-differential media.
True.
The polysaccharide-based hardening agent added to LB media to produce LB agar is derived from what?
Seaweed (algae) extract.
Blood agar is which type of medium?
Differential and enriched
Columbia CNA agar is most closely related to which media: [Show Less]