Microbiology 2124
Exam 1
Sept. 18, 1998
David Demezas
General Instructions: Answer multiple choice questions on the test sheet. Answer other questions in the space provided on the test sheet. Be sure that you answer the question in complete sentences. Write your name on all pages of the test.
Multiple Choice (4 pts each). Chose the most correct answer and mark the corresponding letter on the blank provided to the left of the question.
1. _________ was the first person to observe and describe what he called "wee animalcules" that are called microorganisms today.
A. Robert Hooke
B. Robert Koch
C. John Tyndall
D. Antoni van Leeuwenhoek
E. Joseph Lister
2. The three taxonomic domains are _________.
A. Bacteria, Archaea and Eukarya
B. Bacteria, Archaea and Fungi
C. Fungi, Algae and Protozoa
D. Bacteria, Algae and Fungi
E. Eukarya, Fungi and Algae
3. Which of the following is unique to eukaryotic cells (i.e., never found in prokaryotic cells)?
A. a plasma membrane
B. ribosomes
C. a cell wall
D. a membrane-bound nucleus
E. enzymes
4. The hypothesis that living organisms can originate from nonliving matter is referred to as _________.
A. evolution by natural selection
B. spontaneous generation
C. Gaia hypothesis
D. chemiosmotic theory
E. None of the above
5. Which of the following is (are) required for bacteria to survive and grow?
A. Transcription
B. Translation
C. Replication
D. All of the above
E. None of the above.
6. Which of the following microscopes produces a bright image on a dark background?
A. Bright field microscope
B. Phase contrast microscope
C. Dark field microscope
D. Fluorescent microscope
E. Telescope
7. Which of the following pairs of sugars are the sugar backbone in the peptidoglycan layer?
A. Sucrose and Fructose
B. N-acetyl glucosamine and N-acetyl muramic acid
C. N-acetyl glucosamine and glucose
D. N-acetyl muramic acid and fructose
E. ribose and deoxyribose
8. T or F The peptidoglycan layer of gram negative bacteria is thicker than the layer of gram positive bacteria.
9. A microorganism's response to a chemical gradient (e.g., an attractant) is referred to as _________.
A. phototaxis
B. magneto-taxis
C. aerotaxis
D. chemotaxis
E. all of the above
10. You observed a bacterium with flagella attached at many places around the cell. These are _________.
A. lophotrichous flagella
B. polar flagella
C. peritrichous flagella
D. lophotrichous fimbriae
E. peritrichous pili
11. Which of the following is NOT characteristic of a cell's cytoplasmic membrane?
A. a phospholipid bilayer
B. a highly selective permeability barrier
C. a hydrophobic core and hydrophilic layers on the outside
D. a very rigid (i.e., stiff) membrane
E. integral proteins that span the membrane
12. A sugar is chemically altered as it is transported across the cytoplasmic membrane into a cell. This is referred to as _________.
A. group translocation
B. active transport
C. simple diffusion
D. osmosis
E. facilitated diffusion
13. Lysozyme hydrolyzes which of the following bonds?
A. Ester linkages in phospholipids of the cytoplasmic membrane
B. peptide bonds between adjacent amino acids in the peptidoglycan
C. phosphodiester bonds between nucleotides
D. peptide bonds between adjacent NAM molecules
E. 1,4 glycosidic linkages between NAM and NAG
14. _________ use organic compounds as a source of energy and carbon.
A. Chemolithotrophs
B. Chemoorganotrophs
C. Photoautotrophs
D. Photoheterotrophs
15. T or F A reaction yielding free energy (i.e. [Delta]Goยด is negative) is called an exergonic reaction.
16. The proton motive force may be used to _________.
A. drive the flagella
B. generate ATP
C. transport molecules across the cytoplasmic membrane
D. reverse electron flow to generate NADPH
E. all of the above
17. ATP is made by _________ during glycolysis and _________ as a result of the proton motive force.
A. substrate level phosphorylation / oxidative phosphorylation
B. fermentation / substrate level phosphorylation
C. anaerobic respiration / oxidative phosphorylation
D. oxidative phosphorylation / substrate level phosphorylation
E. None of the above
18. Which of the following types of metabolism does not generate a proton motive force that can be used to make ATP?
A. aerobic respiration
B. anaerobic respiration
C. phototrophic
D. alcohol fermentation
E. chemolithotrophy
19. A total of _________ ATPs are generated during fermentation and _________ ATPs during aerobic respiration.
A. 2 / 38
B. 4 / 32
C. 2 / 2
D. 38 / 38
E. 38 / 4
20. Which of the following best sums the result of aerobic respiration beginning with a molecule of glucose?
A. 2 x CO2; 2 ATPs; 2 x ethanol
B. 2 x lactate; 2 ATPs
C. 2 x ethanol; 4 ATPs
D. 2 x pyruvate ; 4 ATPs
E. 6 x CO2; 38 ATPs
21. T or F Anoxygenic phototrophs produce oxygen gas during photosynthesis.
22. In phototrophic bacteria, ATP is generated using _________ .
A. non cyclic photophosphorylation
B. oxidative phosphorylation
C. cyclic photophosphorylation
D. substrate level photophosphorylation
E. substrate level phosphorylation
23. Which of the following cannot be used by Thiobacillus ferrooxidans as an energy source?
A. Fe+2 B. SO4-2 C. H2S D. So E. All of the above.
24. Methanogenesis, denitrification and sulfate reduction are all forms of _________.
A. aerobic respiration
B. fermentation
C. chemolithotrophy
D. anaerobic respiration
E. phototrophy
25. Which of the following molecules cannot be used as a terminal electron acceptor in anaerobic respiration?
A. SO42-
B. NO3-
C. CO2
D. H2S
E. All of the above.
Each of the following is worth 5 pts. Write your answers on the sheet of paper provided. Your answers should be brief and complete.
26. List Koch's postulates for proving that a specific microorganism causes a specific disease. Make sure they are in the correct order. (hint: there are 4 of them)
27. Label all of the following structures in the diagram below: Lipid A, cytoplasmic membrane, O-polysaccharide, Core polysaccharide, phospholipids, periplasm, porin, ketodeoxyoctonate (KDO), lipopolysaccharide and peptidoglycan.
28. Briefly explain how the electron transport chain of aerobic bacteria is linked to ATP synthesis. (Hint: A diagram may be helpful.)
29. NADPH is required by chemolithotrophs to reduce CO2 for the synthesis cellular carbon. Provide two methods chemolithotrophs use to generate NADPH and explain why there are two methods based on redox potentials.
