Download The following two questions relate to a cell that has an electrical

Biology 150: Principles of Molecular and Cellular Biology
October 20, 2005
Exam #2
Please fill in your name and ID no. on the answer sheet. Be sure to darken the circles
beneath your name and ID number.
Please enter the code for this exam (provided at the bottom on the last page of
the exam) on your scantron sheet (left most column of CODES section). The
code will either be the number 1, 2, 3 or 4. It is critical that you darken the
appropriate circle so that your exam will be scored correctly.
Provide all answers on the answer sheet. If the question is of multiple choice format,
please choose the best answer from the responses that are given. Darken the circle on
the answer sheet completely.
1. The active site of an enzyme is defined as
a. a specific region on the substrate where an enzyme binds
b. a specific region on the enzyme where the substrate binds
c. a specific region on the enzyme where a coenzyme binds
d. a specific region on the enzyme where a non-competitive inhibitor binds
2. A substance that inhibits enzyme action but does not bind to the active site of the enzyme
is termed
a.
a competitive inhibitor of enzyme action
b.
a non-competitive inhibitor of enzyme action
c.
a non-competitive substrate
d.
a coenzyme
3. Enzymes are able to
a. lower the the G of a chemical reaction
b. change an endergonic reaction into an exergonic reaction
c. increase the free energy of the reactants
d. lower the energy of activation
4. A cellular diameter of 40 micrometers is equivalent to
a. 4 millimeters
b. 0.04 millimeter
c. 400 nanometers
d. 4,000 nanometers
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5. NAD+
a. is the oxidized form of the coenzyme
b. is the reduced form of the coenzyme
6. Which of the following is NOT true?
a. glucose : 6 C
b. glyceraldehyde 3 phosphate: 3 C
c. pyruvate: 3 C
d. acetyl CoA: 2 C
e. citrate: 5 C
7. Which of the following is a product of oxidative phosphorylation within the electron
transport chain?
a. H2O
b. O2
c. ADP
d. NADH
e. CO2
8. The conversion of pyruvate to lactate
a. produces NAD+
b. produces NADH
c. requires oxygen
d. produces ATP
9. For each individual glucose molecule that enters glycolysis
a. there is a net yield of two NADH molecules
b. there is a net yield of two ATP molecules
c. two pyruvate molecules are formed
d. a, b, and c are all true
10. For each glucose metabolized, how many acetyl CoA molecules enter the Krebs cycle?
a. one
b. two
c. three
d. four
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11. The delivery of oxygen to exercising muscle is sometimes not sufficient to meet the
demands of oxygen for oxidative phosphorylation. Under these conditions,
a. ATP production will stop completely since no ATP can be generated in the
absence of oxygen
b. lactic acid (lactate) concentrations within the muscle cells would increase
c. ethanol concentrations within the muscle cells would increase
d. ATP will continue to be generated by substrate level phosphorylation within the
Krebs cycle
12. Glycoproteins are a component of plasma membranes. These macromolecules
a. contain short peptide chains attached to polysaccharides
b. are oriented in the plasma membrane such that the carbohydrate portion of the
molecule is embedded within the interior lipid portion of the lipid bilayer
c. are oriented such that the carbohydrate portion of the molecule projects from
intracellular surface of the plasma membrane
d. contain oligosaccharides that are attached to integral proteins such that the
oligosaccharides projects from the extracellular surface of the plasma
membrane
13. Which ONE of the following five molecules within the plasma membrane are most
responsible for ‘self versus non-self’ recognition by cells?
a. cholesterol
b. phospholipids
c. peripheral proteins
d. integral proteins
e. glycoproteins
14. The nuclear envelope
a. is present in all eukaryotic cells
b. is present in all prokaryotic cells
c. consists of a single lipid bilayer identical to the plasma membrane
d. has no visible pores and thereby prevents entry or exit of all molecules into or out of
the nucleus
15. Indicate an appropriate pathway for the vesicular transport of proteins that are secreted
from the cell.
a. rough ER to Golgi apparatus to nucleus
b. rough ER to Golgi apparatus to plasma membrane
c. free ribosomes to Golgi apparatus to plasma membrane
d. free ribosomes to Golgi apparatus to cytoplasmic vesicles
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16. The cell wall of the plant cell is
a. a lipid bilayer containing both peripheral and integral proteins
b. is rigid wall that is located outside the plasma membrane of plant cells
c. is a wall that defines the exterior surface of the central vacuole of plants
d. replaces the plasma membrane in plants cells
17. White blood cells ingest foreign material and then digest this material inside the cell.
Which organelle in the list below is likely to be present in rather high concentrations
within white blood cells compared to cells that do not carry out this specialized function?
a. lysosome
b. Golgi apparatus
c. centrosome
d. rough endoplasmic reticulum
e. chloroplasts
18. Which of the pairs of terms is incorrect?
a. microtubules: tubulin
b. microfilaments: actin
c. intermediate filaments: keratin
d. chromatin: RNA
19. Consider the characteristics of an integral protein that is located within the interior of the
plasma membrane. The amino acids of this protein that are embedded in the plasma
membrane would likely have
a. ionic side chains
b. non-polar side chains
c. polar side chains
20. Consider a poison that inhibits an enzyme that is required for translation (the synthesis of
proteins). In what organelle of the cell would you expect to find this poison?
a. nucleus
b. ribosome
c. mitochondria
d. Golgi apparatus
e. smooth endoplasmic reticulum
21. Which of the following pairs is mismatched?
a. nucleolus: ribosomal RNA
b. nucleus: chromatin
c. lysosome: hydrolysis of macromolecules
d. plasma membrane: lipid bilayer
e. cytoskeleton: vacuoles
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22. During the process of oxidative phosphorylation and chemiosmosis, H+ ions move from
an area of higher concentration to lower concentration through ATP synthase to
generate ATP. Which of the following statements is the most accurate?
a.
H+ ions diffuse from the matrix to the intermembrane space
b.
H+ ions diffuse from the intermembrane space to the matrix
c.
H+ ions are actively transported from the matrix to the intermembrane
space
d.
H+ ions are actively transported from the intermembrane space to the
matrix
23. During cellular respiration and oxidation of 1 molecule of glucose how many ATP are
produced by substrate level phosphorylation and how many ATP are produced by
oxidative phosphorylation?
a.
2 ATP substrate level phosphorylation + 36 ATP oxidative
phosphorylation
b.
10 ATP substrate level phosphorylation + 28 ATP oxidative
phosphorylation
c.
4 ATP substrate level phosphorylation + 34 ATP oxidative
phosphorylation
d.
6 ATP substate level phosphorylation + 32 ATP oxidative phosphorylation
24.
Formation of ATP by oxidative phosphorylation is an example of chemiosmosis.
Which of the following molecules or gradients are required for ATP generation via
chemiosmosis?
a. ATP synthase
b. a H+ gradient
c. ATP phophatase
d. a and b are both true
e. b and c are both true
For each of the following statements, darken ‘a’ if the statement is true only for glycolysis,
‘b’ if the statement is true only for the Krebs cycle, ‘c’ if the statement is true only for the
oxidative phosphorylation reactions within the electron transport chain
25.
26.
27.
Generates FADH2
Generates the most NADH that is produced during cellular respiration
Can continue under anaerobic conditions
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28.
29.
Produces the majority of H2O during cellular respiration
Two molecules of ATP are required for phosphorylation of compounds during the
initial stages of this pathway
30. Which molecule donates electrons later (or furthest along) in the electron transport
chain?
a. NAD+
b. NADH
c. FADH
d. FADH2
31. Acetyl CoA is initially added to oxaloacetate at the start of the Kreb’s cycle to form
citrate. How many carbons are “released” for each Acetyl CoA that enters the Kreb’s
cycle to ultimately regenerate oxaloacetate?
a. 0
b. 1
c. 2
d. 4
e. 6
32. Which of the following statements characterizes a difference between active transport
and facilitated diffusion?
a. active transport involves a carrier protein that is embedded in the membrane while
facilitated diffusion involves movement through the lipid bilayer of the membrane
b. facilitated diffusion is movement of a substance down a concentration gradient while
active transport is movement against a concentration gradient
c. facilitated diffusion includes the movement of water across a semipermeable
membrane while active transport would not include water movement across a
semipermeable membrane
33. An osmotic gradient has resulted in the movement of water from compartment A to
compartment B. What assumptions can be made about the characteristics of the
membrane between these two compartments?
a. the membrane is permeable to all solutes, but not the solvent
b. the membrane is permeable to the solvent, but not the solutes
c. the membrane is permeable to both the solvent and the solutes
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34. Synthesis of the female steroid sex hormone, estrogen, would most likely occur in what
organelle of cells within the ovary?
a. nucleus
b. rough ER
c. smooth ER
d. free ribosome
e. mitochrondria
35. Bound ribosomes
a. are attached to the cytoplasmic surface of the plasma membrane
b. are attached to the outer surface of the mitochondria
c. are attached to the outer (cytosolic) surface of the endoplasmic reticulum
d. are attached to the interior (nuclear) surface of the nuclear envelope
e. are attached to the inner (cisternal) surface of the endoplasmic reticulum
36. The central vacuole of plant cells
a. contains chlorophyll
b. is of constant size, regardless of the water environment for the plant
c. is comparable in size to the ribosomes of the plant cell
d. is encased in a membrane called the tonoplast
For the following questions use the lettered answers to match the structure to its proper
cell type. Choose the cell type that best correlates with the term in the numbered list.
Answers may be used more than once if necessary.
a. a feature of all cells
b. only found in prokaryotic cells
c. only found in eukaryotic cells
d. only found in plant cells
e. only found in animal cells
37.
38.
39.
40.
41.
42.
plasma membrane
central vacuole
tonoplast
nucleoid
membrane enclosed vesicles are present throughout the cell
ribosomes
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43. Which of the following is NOT considered as part of the cytomembrane system?
a. Golgi apparatus
b. inner membrane of the mitochrondria
c. nuclear envelope
d. smooth endoplasmic reticulum
e. rough endoplasmic reticulum
44. Plasmodesmata
a. allow exchange of cytosol between adjoining plant cells
b. are present only in prokaryotic cells
c. are specialized connections between neighboring animal cells
d. is a term for the rigid wall on the outside of all plant cells
45. Order the events numbered 1 through 4 below in a sequence that accurately describes the
order of events leading to synthesis of ATP within the electron transport chain.
1.
Synthesis of ATP via the enzymatic action of ATP synthase
2.
Movement of electrons from one carrier complex to next
3.
Creation of proton gradient
4.
Donations of electrons by NADH
a.
b.
c.
d.
2, 4, 3, 1
3, 4, 2, 1
4, 2, 3, 1
4, 3, 2, 1
46. What is the final electron acceptor in the electron transport chain?
a. NAD+
b. H20
c. CO2
d. O2
47. Which of the following metabolic processes would yield CO2?
a. glycolysis
b. conversion of pyruvate to lactate
c. Krebs cycle
d. electron transport chain
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48. Enzymes that function in glycolysis are located
a.
b.
c.
d.
e.
within the cytosol of the cell
within in the nucleus of the cell
within the intermembrane space of the mitochondria
within the mitochondrial matrix
within the cisternal space of endoplasmic reticulum
49. In the following reaction (moving in the direction of the arrow), which reactant is
oxidized and which reactant is reduced?
Pyruvate + NADH + H+  Lactate + NAD+
a. Pyruvate is oxidized and NADH is reduced
b. Pyruvate is reduced and NADH is oxidized
50. If a significant volume of hypertonic solutions are infused into the blood of a patient, the
osmolarity of the blood (plasma) will increase and red blood cells will
a. shrivel or crenate
b. swell and perhaps burst
c. not change their shape due to their rigid cell walls
Code = 3
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