Microbiology 2124
First In-Term Examination
February 16, 1998
Professor Robert V. Miller, Ph. D.

General Instructions: Answer all questions on your test paper in the spaces provided. Only answers entered into the appropriate spaces will be marked. Read all questions carefully. Do not exceed space provided for the answer. Always provided the best right answer.
Questions 1-25 are 4 points each.

1. Spontaneous generation suggests that life can be formed from ______
a. preexisting life.
b. inorganic materials.
c. bacteria.
d. sperm and egg.

2. The physician who developed what is probably the most important staining procedure in microbiology was______
a. Louis Pasteur.
b. Robert Koch.
c. Richard Pitri.
d. Christian Gram.

3. Yeasts are responsible for the ______
a. fermentation of wine.
b. anthrax.
c. tobacco mosaic disease.
d. cholera.

T F4. Agar is an excellent substance for the growth of bacteria because it mixes easily with liquids, does not melt until it reaches a temperature of >90^oC, and does not gel until a much lower temperature (about 45^oC).

5. You are observing a bacterium in the microscope which has a single whip-like appendage that allows it to move through the medium. This organism would be said to be ______
a. monotrichously flagellated.
b. peritrichously flagellated.
c. monotrichously piliated.
d. peritrichously piliated.

6. The location of the enzymes and other compounds important to chemiosmosis in the prokaryotic bacterial cell is the ______
a. mitochondrium.
b. cell wall.
c. cell membrane.
d. ribosome.

7. The cell walls of bacteria contain a rigid macromolecule that is the site of attack by the enzyme lysozyme. This complex molecule is known as _______.
a. lipid A.
b. teichoic acid.
c. a phospholipid.
d. peptidoglycan.

8. Bacteria that can grow only in the absence of oxygen are said to be _________.
a. aerobic.
b. microaerophilic.
c. facultative.
d. anaerobic.

9. Spherical organisms arranged in random groups of cells that resemble bunches of grapes are referred to as _______.
a. staphylococci.
b. streptococci.
c. sarcinae.
d. cocci.

10. Any metabolic process that releases energy in referred to as _______.
a. fermentation.
b. respiration.
c. catabolism.
d. anabolism.

11. Energy is stored in the cell for later use as _______
a. ADP.
b. AMP.
c. ATP.
e. GDP.

12. The metabolic process in which glucose is converted into pyruvic acid is ________
a. glycolysis.
b. the TCA cycle.
c. fermentation.
d. oxidative phosphorylation.

13. A bacterium that utilizes glucose as an energy source has been isolated. The bacterium will only grow in an anaerobic environment. After the growth of the bacterium, the pH of the growth medium is measured and found to be very acidic. When analyzed, the medium is found to have a high concentration of lactic acid. This bacterium is most likely metabolizing by a process known as _______
a. anaerobic respiration.
b. the TCA cycle.
c. fermentation.
d. oxidative phosphorylation.

14. If you measured the net number of moles of ATP produced per mole of glucose metabolized by the organism in question 13, you would most likely find the number to be _________
a. 38.
b. 4.
c. 19.
d. 2.

15. In chemiosmosis, ____________________ moles of ATP are produced from each molecule of NADH + H⁺.
a. 1
b. 2
c. 3
d. 4

16. Identify the reaction in which ATP is utilized.
a. fructose-6-phosphate fructose-1-6-diphosphate.
b. diphosphoglyceric acid 3-phosphoglyceric acid.
c. phosphoenolpyruvic acid pyruvic acid.
d. [alpha]-ketoglutaric acid succinic acid.

17. In anaerobic respiration, all of the following molecules could be used as the final
electron acceptor except _________
a. NO₃^-.
b. O₂.
c. SO₄^2-.
d. NO₂^-.

18. All of the following types of microorganisms may exist in a unicellular stage. Which type
possesses the prokaryotic cell plan?
a. bacteria
b. algae
c. fungi
d. protozoa

T F 19. Microbiological principles in general may be applied only to microorganisms.

20. A bacterium possesses a transport system for a substrate in which the substance is chemically
altered in the process. Which type of transport system is operating?
a. diffusion
b. facilitated diffusion
c. group translocation
d. active transport

21. The rigidity and shape of the bacterial cell is due to the
a. cell membrane.
b. peptidoglycan layer.
c. the lipopolysaccharide.
d. the teichoic acid layer.

22. In which type of bacterium is the peptidoglycan the most prominent feature as seen in a cross-section under the electron microscope?
a. Gram-negative bacteria
b. Gram-positive bacteria
c. archaea
d. cyanobacteria

23. When the coenzyme (NAD⁺) in a typical dehydrogenation reaction is reduced, the change in the coenzyme involves ______
a. the addition of 1 electron and 1 proton.
b. the addition of 2 electrons and 1 proton.
c. the addition of 1 electron and 2 protons.
d. the addition of 2 electrons and 2 protons.

24. Membrane-bound ATPase synthesizes ATP when _______
a. protons move into the cell.
b. protons move out of the cell.
c. electrons move into the cell.
d. electrons move out of the cell.

25. The energized state of the membrane is expressed quantitatively as the ________
a. redox potential.
b. pH.
c. proton motive force.
d. proton gradient.

26. (10 points) List Koch's postulates in order.

27.(10 points) Draw each of the following cells:
1. Monotrichous rod.
2.Lophotrichous rod.
3.Peritrichous coccus.
4.Amphitrichous spirillum.

28.(12 points) Identify each of the following reactions as occurring in glycolysis (G) or the TCA cycle (T) by placing the correct letter on the line provided.

• _______isocitrate [alpha]-ketoglutarate
• _______3-phosphoglycerate phosphoenolpyruvate
• _______glyceraldehyde-3-phosphate 1,3,-bisphosphoglycerate
• _______oxalacetate + acetyl-CoA citrate
• _______phosphoenolpyruvate pyruvate
• _______succinyl-CoA succinate

29. (10 points) One of the primary purposes of the metabolism of glucose is the generation of percuarsor molecules.
a. Identify three precursors formed in glycolysis.
b.Identify one percursor formed in the TCA cycle.
c.Identify one percursor formed in the Pentose Phosphate Shunt.

30.(8 points) Fill in the blank.
Rod-shaped bacteria are know as "rods" or ______________, whereas spherical bacteria are said to be ______________. Spherical bacteria can be found in several configurations. If they are found in pairs, they are said to be ______________ but if they are found in packets of eight, they are referred to as ______________. ______________ are found in irregular clusters, which resemble bunches of grapes. Long chains of spherical bacteria are called ______________. Spiral-shaped bacteria are called ______________ . Bacteria can also be very long and flexible. These bacteria are referred to as ______________.