Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Solution of Exam 2 - Microbiology - 2011 | BIOL, Exams of Microbiology

Material Type: Exam; Professor: Kearns; Class: MICROBIOLOGY; Subject: Biology; University: Indiana University - Bloomington; Term: Fall 2011;

Typology: Exams

2010/2011

Uploaded on 10/25/2011

jgonsalves
jgonsalves 🇺🇸

5

(1)

1 document

1 / 8

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Microbiology M250 Name: ___________________________
Exam 2 October 19th 2011
MULTIPLE CHOICE (2 points each)
1. You observe individual cells of a bacterium actively moving over a solid surface.
Transmission electron microscopy reveals that the cells produce neither pili nor flagella.
This bacterium is most likely moving by a mechanism of:
a. gliding motility
b. twitching motility
c. floating motility
d. swimming motility
e. swarming motility
2. You observe cells moving vertically in a water column. Transmission electron
micrographs reveal that the cells do not produce flagella but you see crystalline pockets
inside the cytoplasm. This bacterium is most likely moving by a mechanism of:
a. gliding motility
b. twitching motility
c. floating motility
d. swimming motility
e. swarming motility
3. Examibacter mathquestionii is growing in exponential phase. Suppose there are
100,000 E. mathquestionii cells in the culture. How many E. mathquestionii cells will
there be after 6 generations?
a. 600,000
b. 1,200,000
c. 6,400,000
d. 12,000,000
4. If the growth rate of an organism decreases 4 fold, the generation time _________.
a. remains constant.
b. increases 4 fold.
c. decreases 4 fold.
d. cannot be predicted because the two measurements are not related.
pf3
pf4
pf5
pf8

Partial preview of the text

Download Solution of Exam 2 - Microbiology - 2011 | BIOL and more Exams Microbiology in PDF only on Docsity!

Microbiology M250 Name: ___________________________ Exam 2 October 19th^2011 MULTIPLE CHOICE (2 points each)

  1. You observe individual cells of a bacterium actively moving over a solid surface. Transmission electron microscopy reveals that the cells produce neither pili nor flagella. This bacterium is most likely moving by a mechanism of: a. gliding motility b. twitching motility c. floating motility d. swimming motility e. swarming motility
  2. You observe cells moving vertically in a water column. Transmission electron micrographs reveal that the cells do not produce flagella but you see crystalline pockets inside the cytoplasm. This bacterium is most likely moving by a mechanism of: a. gliding motility b. twitching motility c. floating motility d. swimming motility e. swarming motility
  3. Examibacter mathquestionii is growing in exponential phase. Suppose there are 100,000 E. mathquestionii cells in the culture. How many E. mathquestionii cells will there be after 6 generations? a. 600, b. 1,200, c. 6,400, d. 12,000,
  4. If the growth rate of an organism decreases 4 fold, the generation time _________. a. remains constant. b. increases 4 fold. c. decreases 4 fold. d. cannot be predicted because the two measurements are not related.
  1. You need to determine the number of cells in an environmental sample, but you do not know how to grow the cells in the lab. What method of determining cell number would you use? a. Spectrophotometry b. Viable counting c. Dilution plating d. Direct counting
  2. The kinetics of facilitated diffusion versus passive diffusion are shown at the right. Why does the rate of facilitated diffusion plateau at high substrate concentration? a. transport proteins become limiting b. substrate becomes limiting c. protons become limiting d. ATP becomes limiting
  3. The process by which cell expends energy to move molecules from low concentration to high concentration through a membrane is called: a. facilitated diffusion b. thermodynamics c. active transport d. secretion
  4. Micronutrients will most likely be used by bacteria to: a. participate in transport mechanisms b. extend the chemistry of proteins c. assemble macromolecules d. stabilize membranes
  5. Bacteria use siderophores to transport: a. iron b. protons c. sugars d. the transported substrate depends upon the structure of the siderophore
  1. An organism that obtains cellular energy from light, electrons from glucose, and reduced carbon from glucose is called a: a. Photolithoautotroph b. Photolithoheterotroph c. Photoorganoautotroph d. Photoorganoheterotroph
  2. An enzyme accelerates a chemical reaction by all of the following mechanisms except: a. Controlling substrate orientation b. Electrically straining chemical bonds c. Increasing local substrate concentration d. Changing the equilibrium concentrations of reactants and products
  3. A “signal sequence” indicates: a. that a protein is involved in cell division. b. that a protein is folded incorrectly. c. that a protein should be secreted. d. that a protein is an enzyme. MATCHING (2 pts each) 19-22. Metabolic Pathways. For questions 19-22, match the pathways with their functions. Each pathway may be used more than once. a. Entner-Duodorhoff Pathway b. Embden-Myerhoff Parnas Pathway c. B-oxidation Pathway d. Tri-Carboxylic Acid (TCA) Pathway e. Pentose phosphate Pathway C 19. This pathways makes NADH from fatty acids. A 20. This pathway makes 1 ATP per glucose. E 21. This pathway rearranges sugar structures. D 22. This pathway makes NADH from acetyl-CoA.

23-26 Batch growth. Three different bacteria (A, B, and C) are growing at 37°C in separate test tubes with identical media. For questions 23-26, limit your answers only to the 8 hour window of measurement shown in the graph below. a. Bacterium A b. Bacterium B c. Bacterium C d. Cannot tell from the graph C 23. Which bacterium has the greatest yield? B 24. Which bacterium has the longest lag phase? D 25. Which bacterium can grow at the highest temperature? C 26. Which bacterium has the slowest growth rate? 27-31. Cellular proteins: Correctly match the protein below with the statements in questions 27-31. Answers may be used more than once. a. RelA b. Catalase c. Noc d. TolC e. Transketolase B 27. This protein protects the cell from oxygen damage. C 28. This protein inhibits cell division. A 29. This protein binds to the ribosome. A 30. This protein is involved in physiological adaptation to stationary phase. C 31. This protein binds to DNA. TRUE OR FALSE (1 point each) a. True b. False A 32. Growth rate can only be calculated in exponential phase. A 33. All chemical reactions are reversible. B 34. Enzymes in the cell have evolved to operate at Vmax. B 35. Spectrophotometry counts the number of viable cells in a population. A 36. A protein that prevents another protein from folding is called a chaperone. A37. In a chemostat, the bacterial growth rate decreases as dilution rate decreases.

  1. ENERGY AND CATABOLISM. a) What are the three energy intermediates all living things must make? (3pts) Proton Motive Force (PMF) NADH ATP b) Compare the catabolic strategies of fermentation and respiration for an organism growing on glucose. What function does fermentation and respiration have in common? (2pts) How do they differ? (2pts) Both restore the NAD+ pool (2) Fermentation donates electrons back to the substrate (1) whereas respiration donates electrons to an electron transport chain (1).
  2. SECRETION. Imagine that a Gram negative pathogen is infecting human host cells. This pathogen secretes four different proteins by four different secretion systems. Draw the final location of the secreted protein as secreted by each of the four systems indicated below. (4 pts). or
  1. CELLULAR GROWTH. a. Define binary fission (2 points). Cell division (1) that gives rise to two identical daughter cells (1). b. What is the function of FtsZ in binary fission (2pts)? Polymerizes into a ring (1) and recruits the cell wall biosynthesis machinery (1). c. What is the function of MinC in binary fission (2pts)? Inhibits the polymerization of FtsZ (2) d. On the E. coli cell below, draw the location of the FtsZ , MinC , and MinE proteins at the time of initiation of binary fission (3 points) Just showing one shell of MinC/MinE is also okay. The students may indicate dynamism (moving back and forth which is also great). e. Imagine E. coli growing exponentially in nutrient rich broth. Now imagine that the cell can no longer produce the MinE protein. Describe what happens as the cell continues to grow without MinE (2 pts). In the absence of MinE, MinC will not be inhibited. MinC will then inhibit FtsZ everywhere. FtsZ will not be able to form a ring. The cell will not divide. OR Normal MinE depleted