Robbins and Cotran Review of Pathology - Pathology I 10th Edition Final Test Bank
Exam: Practice Questions with Verified Answers and Detailed Rationales, Most
Recent Update, Already Graded A+, Comprehensive Study Guide for Pathology
Board Review
An experiment is conducted in which cells in tissue culture are
subjected to high levels of ultraviolet radiant energy. Electron
microscopy shows cellular damage in the form of increased cytosolic
aggregates of denatured proteins. In situ hybridization reveals that
protein components in these aggregates also are found in proteasomes.
Which of the following substances most likely binds to the denatured
proteins, targeting them for catabolism by cytosolic proteasomes?
A Adenosine monophosphate
B Calcium
C Caspase
D Granzyme B
E Hydrogen peroxide
F Ubiquitin
F Ubiquitin
Heat-shock proteins provide for a variety of cellular "housekeeping"
activities, including recycling and restora- tion of damaged proteins and
removal of denatured pro- teins. Ubiquitin targets denatured proteins
and facilitates their binding to proteasomes, which then break down the
proteins to peptides. ADP increases when ATP is depleted, helping to
drive anaerobic glycolysis. Cytosolic calcium lev- els may increase with
cell injury that depletes ATP; the calci- um activates phospholipases,
endonucleases, and proteases, which damage the cell membranes,
structural proteins, and mitochondria. Caspases are enzymes that
facilitate apopto- sis. Granzyme B is released from cytotoxic T
lymphocytes and triggers apoptosis. Hydrogen peroxide is one of the
acti- vated oxygen species generated under conditions of cellular
ischemia, producing nonspecific damage to cellular struc- tures,
particularly membranes. (CH1)
,At the site of a surgical incision, endothelial cells elaborate vascular
endothelial growth factor. There is sprouting with migration of
endothelial cells into the wound to establish new capillaries. Which of
the following intracellular proteins is most important in facilitating
movement of endothelial cells?
A Actin
B Cytokeratin
C Desmin
D Lamin
E Myosin
A Actin
Actin is a microfilament involved with cell movement. The other
possibilities listed in B to D are intermediate fila- ments, which are larger
than actin but smaller than myosin (a thick filament interdigitating with
actin, required for mus- cle movement). Cytokeratins form cytoskeletal
elements of epithelial cells. Desmin forms the scaffold in muscle cells on
which actin and myosin contract. Lamin is associated with the nuclear
membrane. (CH1)
,In an experiment, release of epidermal growth factor into an area of
denuded skin causes mitogenic stimulation of the skin epithelial cells.
Which of the following proteins is most likely to be involved in
transducing the mitogenic signal from the epidermal cell membrane to
the nucleus?
A Cyclic AMP
B Cyclin D
C Cyclin-dependent kinase
D G proteins
E RAS proteins
E RAS proteins
RAS proteins transduce signals from growth factor re- ceptors, such as
epidermal growth factor, that have intrinsic tyrosine kinase activity. G
proteins perform a similar function for G protein-linked, seven-
transmembrane receptors. Cyclic AMP is an effector in the G protein
signaling pathway. Cyclins and cyclin-dependent kinases regulate the
cell cycle in the nucleus. (CH1)
, Various soluble mediators are added to a cell culture containing
epidermal cells to determine which of the mediators might be useful for
promoting epidermal cell growth. When epidermal growth factor (EGF)
is added, it binds to epidermal cell surface receptors, with subsequent
transcription factor translocation and DNA transcription. This effect in
the epidermal cells is most likely to be mediated through which of the
following intracellular pathways?
A Calcium ion channel
B Cyclic AMP
C Cyclin-dependent kinase
D JAK/STAT system
E Mitogen-activated protein (MAP) kinase
E Mitogen-activated protein (MAP) kinase
The MAP kinase cascade is involved in signaling from activation via cell
surface receptors for growth factors. This pathway is particularly
important for signaling of EGF and fibroblast growth factor. Ligand
binding, such as occurs with acetylcholine at a nerve-muscle junction,
alters the conformation of ion channel receptors to allow flow of spe-
cific ions such as calcium into the cell, changing the electric potential
across the cell membrane. Cyclic AMP is a second messenger that is
typically activated via ligand binding to receptors with seven
transmembrane segments that associ- ate with GTP-hydrolyzing
proteins; chemokine receptors
function in this fashion. Cyclin-dependent kinases act within the nucleus.
JAK/STAT pathways typically are recruited by cytokine receptors. (CH1)
Exam: Practice Questions with Verified Answers and Detailed Rationales, Most
Recent Update, Already Graded A+, Comprehensive Study Guide for Pathology
Board Review
An experiment is conducted in which cells in tissue culture are
subjected to high levels of ultraviolet radiant energy. Electron
microscopy shows cellular damage in the form of increased cytosolic
aggregates of denatured proteins. In situ hybridization reveals that
protein components in these aggregates also are found in proteasomes.
Which of the following substances most likely binds to the denatured
proteins, targeting them for catabolism by cytosolic proteasomes?
A Adenosine monophosphate
B Calcium
C Caspase
D Granzyme B
E Hydrogen peroxide
F Ubiquitin
F Ubiquitin
Heat-shock proteins provide for a variety of cellular "housekeeping"
activities, including recycling and restora- tion of damaged proteins and
removal of denatured pro- teins. Ubiquitin targets denatured proteins
and facilitates their binding to proteasomes, which then break down the
proteins to peptides. ADP increases when ATP is depleted, helping to
drive anaerobic glycolysis. Cytosolic calcium lev- els may increase with
cell injury that depletes ATP; the calci- um activates phospholipases,
endonucleases, and proteases, which damage the cell membranes,
structural proteins, and mitochondria. Caspases are enzymes that
facilitate apopto- sis. Granzyme B is released from cytotoxic T
lymphocytes and triggers apoptosis. Hydrogen peroxide is one of the
acti- vated oxygen species generated under conditions of cellular
ischemia, producing nonspecific damage to cellular struc- tures,
particularly membranes. (CH1)
,At the site of a surgical incision, endothelial cells elaborate vascular
endothelial growth factor. There is sprouting with migration of
endothelial cells into the wound to establish new capillaries. Which of
the following intracellular proteins is most important in facilitating
movement of endothelial cells?
A Actin
B Cytokeratin
C Desmin
D Lamin
E Myosin
A Actin
Actin is a microfilament involved with cell movement. The other
possibilities listed in B to D are intermediate fila- ments, which are larger
than actin but smaller than myosin (a thick filament interdigitating with
actin, required for mus- cle movement). Cytokeratins form cytoskeletal
elements of epithelial cells. Desmin forms the scaffold in muscle cells on
which actin and myosin contract. Lamin is associated with the nuclear
membrane. (CH1)
,In an experiment, release of epidermal growth factor into an area of
denuded skin causes mitogenic stimulation of the skin epithelial cells.
Which of the following proteins is most likely to be involved in
transducing the mitogenic signal from the epidermal cell membrane to
the nucleus?
A Cyclic AMP
B Cyclin D
C Cyclin-dependent kinase
D G proteins
E RAS proteins
E RAS proteins
RAS proteins transduce signals from growth factor re- ceptors, such as
epidermal growth factor, that have intrinsic tyrosine kinase activity. G
proteins perform a similar function for G protein-linked, seven-
transmembrane receptors. Cyclic AMP is an effector in the G protein
signaling pathway. Cyclins and cyclin-dependent kinases regulate the
cell cycle in the nucleus. (CH1)
, Various soluble mediators are added to a cell culture containing
epidermal cells to determine which of the mediators might be useful for
promoting epidermal cell growth. When epidermal growth factor (EGF)
is added, it binds to epidermal cell surface receptors, with subsequent
transcription factor translocation and DNA transcription. This effect in
the epidermal cells is most likely to be mediated through which of the
following intracellular pathways?
A Calcium ion channel
B Cyclic AMP
C Cyclin-dependent kinase
D JAK/STAT system
E Mitogen-activated protein (MAP) kinase
E Mitogen-activated protein (MAP) kinase
The MAP kinase cascade is involved in signaling from activation via cell
surface receptors for growth factors. This pathway is particularly
important for signaling of EGF and fibroblast growth factor. Ligand
binding, such as occurs with acetylcholine at a nerve-muscle junction,
alters the conformation of ion channel receptors to allow flow of spe-
cific ions such as calcium into the cell, changing the electric potential
across the cell membrane. Cyclic AMP is a second messenger that is
typically activated via ligand binding to receptors with seven
transmembrane segments that associ- ate with GTP-hydrolyzing
proteins; chemokine receptors
function in this fashion. Cyclin-dependent kinases act within the nucleus.
JAK/STAT pathways typically are recruited by cytokine receptors. (CH1)
