TEST BANK
,Test Bank For Porth's Essentials of Pathophysiology 5th edition
Chapter 1: Cell Structure and Function
MULTIPLE CHOICE
1. Although the basic structure of the cell plasma membrane is formed by a lipid bilayer,
most ofthe specific membrane functions are carried out by:
A) Bound and transmembrane proteins
B) Complex, long carbohydrate chains
C) Surface antigens and hormone receptors
D) A gating system of selective ion channels
Ans: A
Feedback:
The functions of plasma membrane depend on the presence of proteins that are bound in the lipid
bilayer and some that have the ability to pass freely into and out of the cell.
Carbohydrate chains form a cell coat that surrounds the membrane and that contain surface
antigens and surface hormone receptors. Some ion channels are gated and open only when the
membrane potential changes significantly.
1. Which describes the function of the nucleus?
A) It is basically the site of protein synthesis in the body.
B) It contains the genetic code for the individual.
C) It is the transformer of cellular energy.
D) It initiates the process of aerobic metabolism.
Ans: B
Feedback:
The nucleus contains DNA, which contains the genetic code that contains the information that
controls cells. Ribosomes synthesize protein. Mitochondria transform organic compounds into
cellular energy. Mitochondria require oxygen for aerobic metabolism, using hydrogen and
carbon combined with oxygen molecules to form carbon dioxide and water as energy is released.
2. Which of the following aspects of the function of the nucleus is performed by ribosomal
,RNA (rRNA)?
A) Copying and carrying DNA instructions for protein synthesis
B) Carrying amino acids to the site of protein synthesis
C) Providing the site where protein synthesis occurs
D) Regulating and controlling protein synthesis
Ans: C
Feedback:
There are three types of ribonucleic acid (messenger RNA, ribosomal RNA, and transfer RNA)
that move to the cytoplasm and carry out the actual synthesis of proteins.
Messenger RNA (mRNA) copies and carries the DNA instructions for protein synthesis to the
cytoplasm; ribosomal RNA (rRNA) is the site of protein synthesis; and transfer RNA (tRNA)
transports amino acids to the site of protein synthesis for incorporation into the protein being
synthesized.
3. Which accurately explains the functions of the organelles lysosomes? They:
A) Are sacs filled with enzymes that breakdown and remove foreign substances and worn-
out cell parts
B) Function in association with the endoplasmic reticulum to modify protein end products
and package them into secretory granules or vesicles
C) Are small particles of nucleoproteins that are involved in the synthesis of proteins that
remain in the cell as cytoplasmic structural or functional elements
D) Are a dynamic system of interconnected membranous tubes that functions as a tubular
communication system for transporting various substances from one part of the cell to another
Ans: A
Feedback:
Lysosomes are sacs that are filled with hydrolytic enzymes that aid in the processing and
removal of unwanted substances within the cytoplasm. The Golgi apparatus functions in
association with the endoplasmic reticulum to modify and package substances in preparation for
secretion, whereas ribosomes are small particles of nucleoproteins that are involved in the
synthesis of proteins. The ER is a tubular communication system for transporting various
substances from one part of the cell to another.
4. Impairment in the function of peroxisomes would result in:
, A) Inadequate sites for protein synthesis
B) An inability to transport cellular products across the cell membrane
C) Insufficient energy production within a cell
D) Accumulation of free radicals in the cytoplasm
Ans: D
Feedback:
Peroxisomes function in the control of free radicals; unless degraded, these highly unstable
chemical compounds damage other cytoplasmic molecules. Peroxisomes do not directly
contribute to energy production, protein synthesis, or transport of cellular secretions.
5. Although energy is not made in mitochondria, they are known as the “power plants” of
the cell because they:
A) Contain RNA for protein synthesis
B) Utilize glycolysis for oxidative energy
C) Extract energy from organic compounds
D) Store calcium bonds for muscle contractions
Ans: C
Feedback:
Mitochondria contain the enzymes needed for transforming organic compounds into energy that
is easily accessible to the cell. Mitochondria contain their own DNA. Glycolysis is anaerobic
metabolism and unrelated to oxidative energy. Mitochondria store phosphate bonds (such as in
ATP) to power cellular functions.
6. Semen analysis indicates that the client's sperm have decreased motility. Which of the
following cellular components may be defective within the client's sperm?
A) Ribosomes
B) Microtubules
C) Mitochondria
D) Microfilaments
Ans: B
Feedback:
Med C
, Abnormalities in the structure and function of microtubules and consequent dysfunction of the
flagella may contribute to impaired sperm motility. Ribosomes, microfilaments, and
mitochondria do not directly contribute to movement in cells such as cilia and flagella.
7. When explaining the function of glycolysis as it relates to anaerobic metabolism, the
faculty will mention which of the following key points? Select all that apply.
A) Glycolysis requires the use of oxygen to begin the process.
B) Glycolysis occurs in mitochondrion-lacking cells.
C) Glycolysis provides the majority of the body's energy needs.
D) Pyruvic acid is an end result from a series of reactions that converts glucose.
Ans: B, D
Feedback:
Glycolysis is the anaerobic process by which energy is liberated from glucose, and it is an
important source of energy for cells that lack mitochondria. The process also provides a
temporary source of energy for cells that are deprived of an adequate supply of oxygen.
Glycolysis involves a sequence of reactions that converts glucose to pyruvic acid, with the
concomitant production of ATP from ADP. It accounts for a small minority of the body's energy
needs and results in NADH, hydrogen ions, ATP, and pyruvic acid.
8. Aerobic metabolism, also known as oxidative metabolism, provides energy to the body
by:
A) Removing the phosphate bonds from ATP
B) Combining hydrogen and oxygen to form water
C) Activating pyruvate stored in the cytoplasm
D) Breaking down glucose to form lactic acid
Ans: B
Feedback:
Aerobic metabolism involves the combination of carbon ions from dietary nutrients, hydrogen
ions, and oxygen. The result is carbon dioxide and water as energy is released, which is stored in
ATP. Phosphate bonds are added (not removed from) to ADP to form ATP. Pyruvate is
formedfrom glucose in the anaerobic process of glycolysis and is converted to lactic acid
during anaerobic metabolism.
Med C
, 9. To qeffectively qrelay qsignals, qcell-to-cell qcommunication qutilizes qa qchemical
qmessenger qsystem qto:
A) Displace qsurface qreceptor qproteins
B) Accumulate qwithin qcell qgap qjunctions
C) Bind qto qcontractile qmicrofilaments
D) Release qsecretions qinto qextracellular qfluid
Ans: qD
Feedback:
Signals qare qtransmitted qby qreleasing qchemical qsecretions qinto qextracellular qfluid.
qChemical qsignals qmove qthrough qcell-to-cell qjunctions qto qreach qother qcells qand qmay
qattach qto qsurface qreceptor qproteins. qThe qcytoplasmic qcontractile qmicrofilaments qare
qincapable qof qtransmitting qcommunication qsignals.
10. Which qidentifies qcorrectly qhow qthe qG qprotein–linked qreceptors qare qsimilar?
A) Their qcytosolic qdomain qhas qintrinsic qenzyme qactivity.
B) Insulin qis qan qexample qof qthe qsecond qmessenger qcAMP, qwhich qbinds qto qan
qenzyme-linked qreceptor.
C) These qlinked qreceptors qare qinvolved qin qrapid qsynaptic qsignaling qbetween qcardiac
qelectrical qcells.
D) They qhave qa qligand-binding qextracellular qreceptor qcomponent, qwhich qcauses
qchanges qthat qactivate qthe qG qprotein qon qthe qcytoplasmic qside qof qthe qcell qmembrane.
Ans: qD
Feedback:
Although qthere qare qdifferences qamong qthe qG qprotein–linked qreceptors, qall qshare qa
qnumber qof qfeatures. qThey qall qhave qa qligand-binding qextracellular qreceptor qcomponent,
qwhich qrecognizes qa qspecific qligand qor qfirst qmessenger. qUpon qligand qbinding, qthey qall
qundergo qconformational qchanges qthat qactivate qthe qG qprotein qfound qon qthe qcytoplasmic
qside qof qthe qcell qmembrane. qInstead qof qhaving
a qcytosolic qdomain qthat qassociates qwith qa qG qprotein, qenzyme-linked qreceptors qhave
qcytosolic qdomain qeither qthat qhas qintrinsic qenzyme qactivity qor qthat qassociates qdirectly
qwith qan qenzyme. qThe qbinding qof qthe qhormone qto qa qspecial qtransmembrane qreceptor
qresults qin qactivation qof qthe qenzyme qadenylyl qcyclase qat qthe qintracellular qportion qof
Med C
, qthe qreceptor. qThis qenzyme qthen qcatalyzes qthe
Med C
,Test Bank For Porth's Essentials of Pathophysiology 5th edition
Chapter 1: Cell Structure and Function
MULTIPLE CHOICE
1. Although the basic structure of the cell plasma membrane is formed by a lipid bilayer,
most ofthe specific membrane functions are carried out by:
A) Bound and transmembrane proteins
B) Complex, long carbohydrate chains
C) Surface antigens and hormone receptors
D) A gating system of selective ion channels
Ans: A
Feedback:
The functions of plasma membrane depend on the presence of proteins that are bound in the lipid
bilayer and some that have the ability to pass freely into and out of the cell.
Carbohydrate chains form a cell coat that surrounds the membrane and that contain surface
antigens and surface hormone receptors. Some ion channels are gated and open only when the
membrane potential changes significantly.
1. Which describes the function of the nucleus?
A) It is basically the site of protein synthesis in the body.
B) It contains the genetic code for the individual.
C) It is the transformer of cellular energy.
D) It initiates the process of aerobic metabolism.
Ans: B
Feedback:
The nucleus contains DNA, which contains the genetic code that contains the information that
controls cells. Ribosomes synthesize protein. Mitochondria transform organic compounds into
cellular energy. Mitochondria require oxygen for aerobic metabolism, using hydrogen and
carbon combined with oxygen molecules to form carbon dioxide and water as energy is released.
2. Which of the following aspects of the function of the nucleus is performed by ribosomal
,RNA (rRNA)?
A) Copying and carrying DNA instructions for protein synthesis
B) Carrying amino acids to the site of protein synthesis
C) Providing the site where protein synthesis occurs
D) Regulating and controlling protein synthesis
Ans: C
Feedback:
There are three types of ribonucleic acid (messenger RNA, ribosomal RNA, and transfer RNA)
that move to the cytoplasm and carry out the actual synthesis of proteins.
Messenger RNA (mRNA) copies and carries the DNA instructions for protein synthesis to the
cytoplasm; ribosomal RNA (rRNA) is the site of protein synthesis; and transfer RNA (tRNA)
transports amino acids to the site of protein synthesis for incorporation into the protein being
synthesized.
3. Which accurately explains the functions of the organelles lysosomes? They:
A) Are sacs filled with enzymes that breakdown and remove foreign substances and worn-
out cell parts
B) Function in association with the endoplasmic reticulum to modify protein end products
and package them into secretory granules or vesicles
C) Are small particles of nucleoproteins that are involved in the synthesis of proteins that
remain in the cell as cytoplasmic structural or functional elements
D) Are a dynamic system of interconnected membranous tubes that functions as a tubular
communication system for transporting various substances from one part of the cell to another
Ans: A
Feedback:
Lysosomes are sacs that are filled with hydrolytic enzymes that aid in the processing and
removal of unwanted substances within the cytoplasm. The Golgi apparatus functions in
association with the endoplasmic reticulum to modify and package substances in preparation for
secretion, whereas ribosomes are small particles of nucleoproteins that are involved in the
synthesis of proteins. The ER is a tubular communication system for transporting various
substances from one part of the cell to another.
4. Impairment in the function of peroxisomes would result in:
, A) Inadequate sites for protein synthesis
B) An inability to transport cellular products across the cell membrane
C) Insufficient energy production within a cell
D) Accumulation of free radicals in the cytoplasm
Ans: D
Feedback:
Peroxisomes function in the control of free radicals; unless degraded, these highly unstable
chemical compounds damage other cytoplasmic molecules. Peroxisomes do not directly
contribute to energy production, protein synthesis, or transport of cellular secretions.
5. Although energy is not made in mitochondria, they are known as the “power plants” of
the cell because they:
A) Contain RNA for protein synthesis
B) Utilize glycolysis for oxidative energy
C) Extract energy from organic compounds
D) Store calcium bonds for muscle contractions
Ans: C
Feedback:
Mitochondria contain the enzymes needed for transforming organic compounds into energy that
is easily accessible to the cell. Mitochondria contain their own DNA. Glycolysis is anaerobic
metabolism and unrelated to oxidative energy. Mitochondria store phosphate bonds (such as in
ATP) to power cellular functions.
6. Semen analysis indicates that the client's sperm have decreased motility. Which of the
following cellular components may be defective within the client's sperm?
A) Ribosomes
B) Microtubules
C) Mitochondria
D) Microfilaments
Ans: B
Feedback:
Med C
, Abnormalities in the structure and function of microtubules and consequent dysfunction of the
flagella may contribute to impaired sperm motility. Ribosomes, microfilaments, and
mitochondria do not directly contribute to movement in cells such as cilia and flagella.
7. When explaining the function of glycolysis as it relates to anaerobic metabolism, the
faculty will mention which of the following key points? Select all that apply.
A) Glycolysis requires the use of oxygen to begin the process.
B) Glycolysis occurs in mitochondrion-lacking cells.
C) Glycolysis provides the majority of the body's energy needs.
D) Pyruvic acid is an end result from a series of reactions that converts glucose.
Ans: B, D
Feedback:
Glycolysis is the anaerobic process by which energy is liberated from glucose, and it is an
important source of energy for cells that lack mitochondria. The process also provides a
temporary source of energy for cells that are deprived of an adequate supply of oxygen.
Glycolysis involves a sequence of reactions that converts glucose to pyruvic acid, with the
concomitant production of ATP from ADP. It accounts for a small minority of the body's energy
needs and results in NADH, hydrogen ions, ATP, and pyruvic acid.
8. Aerobic metabolism, also known as oxidative metabolism, provides energy to the body
by:
A) Removing the phosphate bonds from ATP
B) Combining hydrogen and oxygen to form water
C) Activating pyruvate stored in the cytoplasm
D) Breaking down glucose to form lactic acid
Ans: B
Feedback:
Aerobic metabolism involves the combination of carbon ions from dietary nutrients, hydrogen
ions, and oxygen. The result is carbon dioxide and water as energy is released, which is stored in
ATP. Phosphate bonds are added (not removed from) to ADP to form ATP. Pyruvate is
formedfrom glucose in the anaerobic process of glycolysis and is converted to lactic acid
during anaerobic metabolism.
Med C
, 9. To qeffectively qrelay qsignals, qcell-to-cell qcommunication qutilizes qa qchemical
qmessenger qsystem qto:
A) Displace qsurface qreceptor qproteins
B) Accumulate qwithin qcell qgap qjunctions
C) Bind qto qcontractile qmicrofilaments
D) Release qsecretions qinto qextracellular qfluid
Ans: qD
Feedback:
Signals qare qtransmitted qby qreleasing qchemical qsecretions qinto qextracellular qfluid.
qChemical qsignals qmove qthrough qcell-to-cell qjunctions qto qreach qother qcells qand qmay
qattach qto qsurface qreceptor qproteins. qThe qcytoplasmic qcontractile qmicrofilaments qare
qincapable qof qtransmitting qcommunication qsignals.
10. Which qidentifies qcorrectly qhow qthe qG qprotein–linked qreceptors qare qsimilar?
A) Their qcytosolic qdomain qhas qintrinsic qenzyme qactivity.
B) Insulin qis qan qexample qof qthe qsecond qmessenger qcAMP, qwhich qbinds qto qan
qenzyme-linked qreceptor.
C) These qlinked qreceptors qare qinvolved qin qrapid qsynaptic qsignaling qbetween qcardiac
qelectrical qcells.
D) They qhave qa qligand-binding qextracellular qreceptor qcomponent, qwhich qcauses
qchanges qthat qactivate qthe qG qprotein qon qthe qcytoplasmic qside qof qthe qcell qmembrane.
Ans: qD
Feedback:
Although qthere qare qdifferences qamong qthe qG qprotein–linked qreceptors, qall qshare qa
qnumber qof qfeatures. qThey qall qhave qa qligand-binding qextracellular qreceptor qcomponent,
qwhich qrecognizes qa qspecific qligand qor qfirst qmessenger. qUpon qligand qbinding, qthey qall
qundergo qconformational qchanges qthat qactivate qthe qG qprotein qfound qon qthe qcytoplasmic
qside qof qthe qcell qmembrane. qInstead qof qhaving
a qcytosolic qdomain qthat qassociates qwith qa qG qprotein, qenzyme-linked qreceptors qhave
qcytosolic qdomain qeither qthat qhas qintrinsic qenzyme qactivity qor qthat qassociates qdirectly
qwith qan qenzyme. qThe qbinding qof qthe qhormone qto qa qspecial qtransmembrane qreceptor
qresults qin qactivation qof qthe qenzyme qadenylyl qcyclase qat qthe qintracellular qportion qof
Med C
, qthe qreceptor. qThis qenzyme qthen qcatalyzes qthe
Med C
