TEST BANK for Pathophysiology 9th Edition
Chapter 1: Cellular Biology
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Multiple Choice
1. Which component of the cell prodNuUceRsSIhNyGdTroBg.CeO
nMperoxide (H2O2) by using oxygen to
remove hydrogen atoms from specific substrates in an oxidative reaction?
a. Lysosomes c. Ribosomes
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b. Peroxisomes d. Oxyhydrosomes
ANS: B
Peroxisomes are so named because they usually contain enzymes that use oxygen to
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remove hydrogen atoms from specific substrates in an oxidative reaction that produces
H2O2, which is a powerful oxidant and potentially destructive if it accumulates or escapes
from peroxisomes. Ribosomes are RNA-protein complexes (nucleoproteins) that are
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synthesized in the nucleolus and secreted into the cytoplasm through pores in the nuclear
envelope called nuclear pore complexes. Lysosomes are saclike structures that originate
from the Golgi complex and contain more than 40 digestive enzymes called hydrolases,
which catalyze bonds in proteins, lipids, nucleic acids, and carbohydrates. Oxyhydrosomes
are involved in enzyme production.
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2. Which statement best describes the cellular function of metabolic absorption?
a. Cells can produce proteins. c. Cells can take in and use nutrients.
b. Cells can secrete digestive enzymes. d. Cells can synthesize fats.
ANS: C
In metabolic absorption, all cells take in and use nutrients and other substances from their
surroundings. The remaining options are not inclusive in their descriptions of cellular
metabolic absorption.
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3. Most of a cell’s genetic information, including RNA and DNA, is contained in the:
a. Mitochondria c. Nucleolus
b. Ribosome d. Lysosome
, ANS: C
The nucleus contains the nucleolus, a small dense structure composed largely of RNA,
most of the cellular DNA, and the DNA-binding proteins, such as the histones, which
regulate its activity. The other options do not contain most of a cell’s genetic information.
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4. Which cell component is capable of cellular autodigestion when it is released during cell
injury?
a. Ribosome c. Smooth endoplasmic reticulum
b. Golgi complex d. Lysosomes
ANS: D
The lysosomal membrane acts as a protective shield between the powerful digestive
enzymes within the lysosome and the cytoplasm, preventing their leakage into the
cytoplasmic matrix. Disruption of the membrane by various treatments or cellular injury
leads to a release of the lysosomal enzymes, which can then react with their specific
substrates, causing cellular self-digestion. The other options do not correctly describe this
process.
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5. What is the sequence of steps in the development of a digestive enzyme by the pancreas
cells from the initial transcription to the release from the cell?
a. The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the
ribosome for synthesis, and is transported in a secretory vesicle to the cell
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membrane.
b. The enzyme is transcribed from RNA by DNA in the nucleus, proceeds to the
lysosome for synthesis, and is transported in an encapsulated membrane to the cell
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membrane.
c. The enzyme is transcribed by the mitochondria in the nucleus, proceeds to the
ribosome for synthesis, and is transported in a cytoskeleton to the cell membrane.
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d. The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the
Golgi complex for synthesis, and is transported in a cytosol to the cell membrane.
ANS: A
The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the ribosome
for synthesis, and is transported in a secretory vesicle to the cell membrane. The other
options do not correctly describe this process.
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6. During which phase of the cell cycle is DNA synthesized?
a. G1 c. G2
b. S d. M
ANS: B
The four designated phases of the cell cycle are: (1) the G1 phase (G = gap), which is the
period between the M phase (M = mitosis) and the start of DNA synthesis; (2) the S phase
(S = synthesis), during which DNA is synthesized in the cell nucleus; (3) the G2 phase,
during which RNA and protein synthesis occurs, the period between the completion of
DNA synthesis and the next phase (M); and (4) the M phase, which includes nuclear and
cytoplasmic division.
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7. What organic compound facilitates transportation across cell membranes by acting as
receptors, transport channels for electrolytes, and enzymes to drive active pumps?
a. Lipids c. Proteins
b. Proteases d. Carbohydrates
ANS: C
Proteins act as (1) recognition and binding units (receptors) for substances moving in and
out of the cell; (2) pores or transport channels for various electrically charged particles
called ions or electrolytes and specific carriers for amino acids and monosaccharides; and
(3) specific enzymes that drive active pumps that promote the concentration of certain
ions, particularly potassium (K+), within the cell while keeping concentrations of other
ions, for example, sodium (Na+), below the concentrations found in the extracellular
environment. The other options do not correctly describe this process.
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8. Understanding the various steps of proteolytic cascades, such as caspase-mediated
apoptosis and complement cascades, may be useful in designing drug therapy for which
human diseases?
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a. Cardiac and vascular disorders
b. Autoimmune and malignant disorders
c. Gastrointestinal and renal disorders
d. Endocrine and gastrointestinal disorders
ANS: B
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Understanding the various steps involved in this process is crucial for designing drug
interventions. Dysregulation of proteases features prominently in many human diseases,
including cancer, autoimmunity, and neurodegenerative disorders. The other options do
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not correctly describe this process.
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9. Which structure prevents water-soluble molecules from entering cells across the plasma
membrane?
a. Carbohydrate chains c. Membrane channel proteins
b. Glycoprotein channels d. Lipid bilayer
ANS: D
The bilayer’s structure accounts for one of the essential functions of the plasma
membrane. It is impermeable to most water-soluble molecules (molecules that dissolve in
water) because the water-soluble molecules are insoluble in the oily core region. The
bilayer serves as a barrier to the diffusion of water and hydrophilic substances while
allowing lipid-soluble molecules, such as oxygen (O2) and carbon dioxide (CO2), to
diffuse through it readily. The other options do not correctly describe this process.
PTS: 1 REF: Pages 12-13
10. The fluid mosaic model explains:
a. How a cell membrane functions
b. Why our bodies appear to be solid
c. How tissue is differentiated
d. How fluid moves between the intracellular and extracellular compartments
ANS: A
, The fluid mosaic model accounts for the flexibility of cellular membranes, their
self-sealing properties, and their impermeability to many substances. The remaining
options do not explain the mosaic model.
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11. Which form of cell communication is used to communicate within the cell itself and with
other cells in direct physical contact?
a. Protein channel (gap junction)
b. Plasma membrane–bound signaling molecules (involving receptors)
c. Hormone secretion such as neurotransmitters
d. Extracellular chemical messengers such as ligands
ANS: A
Cells communicate by using hundreds of kinds of signal molecules, for example, insulin.
Cells communicate in three main ways; they display plasma membrane–bound signaling
molecules (receptors) that affect the cell itself and other cells in direct physical contact.
The other options do not correctly describe this process.
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12. Which mode of chemical signaling uses blood to transport communication to cells some
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distance away?
a. Paracrine c. Neurotransmitter
b. Autocrine d. Hormonal
ANS: D
Chemical signaling can be classified into three categories: (1) local-chemical mediator, (2)
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hormone, and (3) neurotransmitter. In the local-chemical mediator model, the secreted
chemical acts on the cells in the immediate environment. Hormones are used for
communication with distant target cells for example, cells can secrete a chemical and rely
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on the blood system to deliver the signal to a distant cell. Finally, neurotransmitters are
secreted by neurons to stimulate an adjoining cell. For example, a neuron might secrete
acetylcholine to stimulate the movement of a muscle cell.
A
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13. Which mode of chemical signaling uses local chemical mediators that are quickly taken
up, destroyed, or immobilized?
a. Paracrine c. Neurotransmitter
b. Autocrine d. Hormone
ANS: A
In paracrine signaling, cells secrete local chemical mediators that are quickly taken up,
destroyed, or immobilized. The other options do not correctly describe this process.
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14. Neurotransmitters affect the postsynaptic membrane by binding to:
a. Lipids c. Amphipathic lipids
b. Ribosomes d. Receptors
ANS: D
In each type of chemical signaling, the target cell receives the signal by first attaching to
its receptors. The other options do not correctly describe this process.
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15. How do cells receive communication from the extracellular fluid surrounding them?
a. Protein channel (gap junction)
b. Plasma membrane–bound signaling molecules (involving receptors)
c. Hormone secretion such as neurotransmitters
d. Chemical messengers such as ligands
ANS: D
Cellular communication can occur by the binding of a chemical massager (a ligand) to a
specific membrane receptor that is closely associated with the channel (e.g., G proteins).
The other options do not correctly describe how cells communicate.
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16. When a second message is necessary for extracellular communication to be activated, it is
provided by which one?
a. Guanosine triphosphate (GTP) c. Adenosine triphosphate (ATP)
b. Adenosine monophosphate (AMP) d. Guanosine diphosphate (GDP)
ANS: B
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The two major second messenger pathways are cyclic AMP (cAMP) and calcium (Ca++).
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17. Under anaerobic conditions, what process provides energy for the cell?
a. Oxidative phosphorylation c. Lactolysis
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b. Glycolysis d. Passive transport
ANS: B
Glycolysis produces a net of two molecules of ATP per glucose molecule through the
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process of oxidation or the removal and transfer of a pair of electrons. The other options
do not correctly identify an anaerobic process that provides energy to the cell.
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18. What is the mechanism by which the energy produced from carbohydrates, proteins, and
lipids is transferred to adenosine triphosphate (ATP)?
a. Anaerobic glycolysis c. Oxidative phosphorylation
b. Oxidative cellular metabolism d. Tricarboxylic acid phosphorylation
ANS: C
Oxidative phosphorylation occurs in the mitochondria and is the mechanism by which the
energy produced from carbohydrates, fats, and proteins is transferred to ATP. The other
options do not correctly identify the mechanism described in the question.
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19. Passive transport is best described with which statement?
a. Being driven by osmosis, hydrostatic pressure, and diffusion
b. Involving receptors that can bind with substances being transported
, c. Being capable of transporting macromolecules
d. Requiring energy generated by the cell
ANS: A
Water and small electrically uncharged molecules move easily through pores in the plasma
membrane’s lipid bilayer. This process, called passive transport, naturally occurs through
any semipermeable barrier. It is driven by osmosis, hydrostatic pressure, and diffusion, all
of which depend on the laws of physics and do not require life. The other options do not
correctly describe passive transport.
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20. Active transport occurs across which type of membranes?
a. Membranes that have a higher concentration of the solute on the outside of the cell
b. Membranes that are semipermeable to water and small electrically uncharged
molecules
c. Membranes that have receptors that are capable of binding with the substances to
be transported
d. Membranes that have a cell membrane that is hydrophobic rather than hydrophilic
ANS: C
Some molecules are moved into the cell by mechanisms of active transport, which require
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receptors that are capable of recognizing and binding with the substance to be transported.
Diffusion is the movement of a solute molecule from an area of greater solute
concentration to an area of lesser solute concentration. Hydrostatic pressure is the
mechanical force of water pushing against cellular membranes. Osmosis is the movement
of water down a concentration gradient; that is, across a semipermeable membrane from a
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region of higher water concentration to a low water concentration
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21. Which method of transport uses transmembrane proteins with receptors with a high degree
of specificity for the substance being transported?
a. Active c. Transmembranous
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b. Mediated d. Passive
ANS: B
Mediated transport (passive and active) involves integral or transmembrane proteins with
receptors having a high degree of specificity for the substance being transported. Inorganic
anions and cations (e.g., Na+, K+, Ca++, chloride [Cl–], bicarbonate [HCO3–]) and charged
and uncharged organic compounds (e.g., amino acids, sugars) require specific transport
systems to facilitate movement through different cellular membranes. The remaining
options do not correctly identify the process described.
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22. The movement of fluid across the arterial end of capillary membranes into the interstitial
fluid surrounding the capillary is an example of which fluid movement process?
a. Hydrostatic pressure c. Diffusion
b. Osmosis d. Active transport
ANS: A
