Biology 260
Stavney
Microbiology
Name
Lecture Exam I
100 points total. Multiple choice questions are 2 pts each. Directions:
1. First, write your name at the top of this exam.
2. On a computerized answer form, fill out your name, date, class, and exam number
3. Write the first three letters of your last name across the back top part of the computer form.
4. Answer all the multiple-choice, true-false questions directly on a computerized answer form,
filling in the rectangles with a #2 pencil that correspond to the correct answers.
5. Complete the short answer sheet at the back of the exam, including putting your name on that
sheet.
6. Separate the short answer sheet from the rest of the questions, fold it in half lengthwise, and
write the first three letters of your last name in the blanks provided.
7. Insert your computer form into the folded sheet.
8. Insert the folded short answer sheet in between the pages of these questions.
9. Submit your exam
Completed exam
for student Joe Smith
1. Who was the first scientist to show that fly larvae (maggots) do not spontaneously form on meat but
are hatched from eggs laid by adult flies?
a. Louis Pasteur
b. Alexander Fleming
c. Robert Hooke
d. Francesco Redi
e. Lazzaro Spallanzani
2. The idea that simple organisms could develop from a “vital force” in the air is known as:
a. pasteurization
b. spontaneous generation
c. biogenesis
d. the cell theory
e. the germ theory of disease
3. The formal steps (postulates) by which a microbiologist can demonstrate that a particular disease is
caused by a particular microbe were first laid down by
a. Louis Pasteur
b. Robert Koch
c. Alexander Fleming
d. Edward Jenner
e. Ignaz Semmelweis
4. The idea that new cellular life arises from pre-existing cellular life is part of which larger concept?
a. Spontaneous Generation
b. Principle of Vaccination
c. Pasteurization
d. Cell Theory
e. Germ Theory of Disease
Bio 260
Microbiology
Exam I pg 1
5. The leading cause of death in Southeast Asia and Africa today is:
a. heart attacks
b. accidents
c. strokes
d. infectious disease
e. cancer
------------------------------------------------------------------------------------------------------TRUE/FALSE (Answer “a” if true and “b” if false)
6. Most microbes are capable of causing human disease.
7. The bond between two separate molecules of water is a covalent bond.
8. An oxidizing agent like hydrogen peroxide causes damage by donating electrons to other molecules.
-----------------------------------------------------------------------------------------------------9. The chemical functional group known as the carboxyl group (-COOH), can be found in which
molecules below?
a. nucleic acids
b. phospholipids
c. polysaccharides
d. sterols
e. amino acids
10. Chemical buffers are put in media because they:
a. absorb the shock when microbes are shaken in a flask
b. increase the pH so the medium won’t become too acidic
c. absorb H+ or OH- and therefore prevent accumulation of these ions
d. decrease the osmolarity of the medium so microbes won’t swell with water
e. provide an important nutrient that microbes need to construct protein molecules
11. The structure of chitin can be written out as:
a. NAG-NAM-NAG-NAM-NAG
b. glucose-glucose-glucose-glucose
c. four interlocking carbon rings
d. NAG-NAG-NAG-NAG-NAG
e. glycine-tryptophan-alanine-methionine
12. Which of the following is a function of sterols?
a. catalyze chemical reactions
b. energy storage
c. structural support
d. maintain flexibility of cell membrane
e. store hereditary information
13. Which of the following is present in gram negative bacteria but not gram positive bacteria?
a. peptidoglycan
b. an outer membrane
c. tetrapeptide crosslinking chains
d. DNA in a single circular loop
e. cholesterol
Bio 260
Microbiology
Exam I pg 2
15. An exergonic (exothermic) reaction, such as the one
shown to the right, is one that:
a. releases energy
b. does’t require enzymes to proceed
c. usually is coupled to the release of ATP energy
d. occurs only under anaerobic conditions
e. speeds up when the temperature decreases
Energy level
14. The function of chloroplasts in eukaryotic cells is:
a. photosynthesis
b. “subway terminal” for proteins
c. packaging and modifying factory for proteins
d. cellular respiration
e. storage of the main genetic information
Time
-----------------------------------------------------------------------------------------------------------------The following questions apply to the diagram of the gram-positive encapsulated prokaryotic cell below.
For each question, answer using the letter(s) at the end of each pointer. For answers more than one letter,
like “ab”, fill in BOTH “a” and “b” on your answer sheet for that question.
16. Which pointer indicates the location of the nucleoid?
17. Which structure is composed of sticky or slimy carbohydrates?
---------------------------------------------------------------------------------------------------------------------
Bio 260
Microbiology
Exam I pg 3
18. Suppose some E. coli bacteria are inoculated into a glucose fermentation tube or PR tube just as we
did in the laboratory. How many ATP are produced by a single bacterial cell when 7 molecules of
glucose are fermented.
a. 3.5 ATP
b. 7 ATP
c. 10.5 ATP
d. 14 ATP
e. between 252-266 ATP
19. The energy used to build the hydrogen ion/proton (H+) gradient across the cell membrane during
aerobic cellular respiration is carried to the electron transport chain by:
a. O2
b. NADH and FADH2
c. NO3-2, SO4-2, or CO3-2
d. ATP
e. Acetyl CoA
20. Bacteria which cause food spoilage in canned salmon, surviving the high temperatures used in
canning must be:
a. alkalophiles
b. thermophiles
c. psychrophiles
d. mesophiles
e. halophiles
21. One way to test whether a microbe is an aerobe is to test for the presence of the enzyme:
a. oxidase
b. catalase
c. NAD+ reductase
d. amylase
e. carboxypeptidase
22. An example of a medium which allows you to enhance and support the growth of a specific group of
target bacteria over other microbes would be:
a. any selective medium
b. any differential medium
c. nutrient agar
d. alcohol agar
e. enrichment agar
23. The bulk of the carbon dioxide released during aerobic cellular respiration occurs during:
a. fermentation
b. electron transport chain
c. glycolysis
d. ATP production at the ATP mill
e. Krebs Cycle
Bio 260
Microbiology
Exam I pg 4
24. In the life cycle of the bacterial culture shown above, what would be the best time to harvest cells in
order to get reliable gram staining results?
a. 0-1 hours
b. 1-3 hours
c. 3-5 hours
d. 5-7 hours
e. Any time would work equally well
25. Which of the following end products are formed by yeast performing fermentation?
a. pyruvate
b. water
c. lactic acid
d. ethanol and CO2
e. 34-38 ATP per glucose
26. For glycolysis to run smoothly, it must have a continuous supply of glucose and
a. pyruvate
b. NAD+
c. NADH
d. FAD
e. H2O
.
27. The high energy electrons in the C-C covalent bonds in glucose end up in which substance after
cellular respiration of a single glucose molecule is complete?
a. NADH
b. pyruvate
c. water
d. ATP
e. carbon dioxide
28. A strong alkaline solution would have a pH of about:
a. 2
b. 5
c. 7
d. 8
e. 13
Bio 260
Microbiology
Exam I pg 5
29. The monomers of lipids are:
a. fatty acids and glycerol
b. nucleotides
c. monosaccharides
d. amino acids
e. peptides
30. The function of glycogen in living things is:
a. energy storage
b. chemical messaging (hormone)
c. structural support
d. storage of genetic information
e. movement/motility
31. Amino acids are the building blocks used to make:
a. DNA and RNA
b. polysaccharides
c. triglycerides
d. protein
e. starch
32. Folded proteins at the quaternary (fourth) level of structure exhibit which feature(s) special to this
level of folding?
a. an amino acid sequence
b. more than one polypeptide chain
c. alpha helices
d. pleated sheets
e. disulfide bonds, ionic bonds, and polar/non-polar interactions
33. The biological molecule shown at the right is used in human
bodies to store energy and sometimes provide heat insulation.
It is a(n):
a. polysaccharide
b. phospholipid
c. RNA molecule
d. protein
e. fat
34. The molecule shown at the right is a part of which biomolecule below?
a. starch
b. protein
c. sterols
d. glycogen
e. nucleic acids
Bio 260
Microbiology
H
H2N
C
R
O
C
OH
Exam I pg 6
35. Cell membranes are made primarily of
a. amino acids
b. cholesterol
c. phospholipids
d. carbohydrates
e. microtubules
36. A bacterial cell with an internal solute concentration of 1% is placed into a beaker of pure water
(solute concentration = 0%). What will happen to this cell?
a. Nothing particular will happen to the cell.
b. It will swell
c. It will shrink
d. The cell wall will become thicker
e. The volume of cytoplasm in the cell will decrease
------------------------------------------------------------------------------------------------------------------------Use the picture below to answer the following questions. If the correct answer is more than one letter
long, like "ab", fill in BOTH "a" and "b" on your answer sheet for that question.
37. Which structure can be called the "shipping and packaging station" of the cell (the Fed Ex or UPS
station) where proteins are modified and packaged for destinations around the cell?
38. Where in the cell above is genetic information stored?
Bio 260
Microbiology
Exam I pg 7
39. Which of the following methods for quantifying the bacterial concentration allows the microbiologist
to get a very accurate count of only live, “viable” cells?
a. Dilution and pour plate method
b. Direct microscopy using a counting chamber
c. Measurement of turbidity (blocking of light) using a spectrophotometer
d. The Most Probable Number Method
e. Smearing, fixing, and staining a small volume of cells
40. When bacteria break down peptone (short amino acid chains) as their sole energy source, what
happens to the medium in which they are growing?
a. The medium increases in temperature (it’s an exothermic reaction)
b. The medium decreases in temperature (it’s an endothermic reaction)
c. The medium increases in pH
d. The medium decreases in pH
e. The medium increases in sugar content
41. The genus Enterobacter contains bacteria that ferment glucose into an unusual product. This product
produces a positive result when Voges-Proskauer reagent (of MRVP) is added to a grown culture. What
is this unique fermentation product?
a. acetoin
b. lactic acid
c. ethanol
d. butyric acid
e. propionic acid
Bio 260
Microbiology
Exam I pg 8
ESSAY PAGE
Exam I Bio 250
Name
18 points total. After completing both sides of this sheet, gently separate it from the rest of the exam. Write your
name at the top right, turn it over, and fill in the first three letters of your last name in the blanks provided. Then
fold this sheet lengthwise, placing your last name letters on the outside and facing up. Insert your computer form
into the folded sheet, and then your folded sheet between the pages of your exam questions. Submit this package,
with your name on the question sheets, to the instructor when you are finished.
A. 2 pt. Polysaccharides are broken apart by a reaction involving the splitting of a water molecule. This
specific type of chemical reaction is called:
B. 4 pt. Define the term “feedback inhibition” as it applies to synthesis pathways catalyzed by a team of
enzymes.
C. 2 pts. Some bacteria, particularly those of genera Bacillus and Clostridium, are able to make seed-like
structures that are resistant to chemical, UV, and radiation damage and can become completely
dehydrated. Such structures are called:
D. 4 pts. Name and describe an environmental condition that would slow down the catalytic rate of an
enzyme be specific on how this condition alters the “health” of the enzyme. (For example, you could say
that the greater the concentration of glucose molecules, the stickier it makes the enzyme; this would
increase the catalytic rate as reactant molecules become stuck to it more often).
E. 6 pts. Name and describe a way to successfully culture obligate anaerobes in the laboratory using
either liquid media and/or special equipment.
Bio 260
Microbiology
Exam I pg 9
First 3 letters of your last name here
Bio 260
Microbiology
Exam I pg 10