NU 545 Comprehensive Predictor Verified Multiple
Choice and Conceptual Actual Exam Questions
With Reviewed 100% Correct Detailed Answers
Guaranteed Pass!!Current Update
1. What is chemical signaling? - ANSWER Primary means of cell-to-cell
communication. 5 forms of signaling mediated by secreted molecules: (1)
Contact-dependent signaling requires cells to be in close membrane-
membrane contact; (2) Paracrine signaling- cells secrete local chemical
mediators that are quickly absorbed, destroyed, or immobilized; (3)
Autocrine signaling- cells produce signals that they, themselves, respond
to (cancer cells); (4) Hormonal signaling involves specialized endocrine
cells that secrete chemicals called hormones (TSH). Hormones are
released by one set of cells and travel through the tissue and through the
bloodstream to produce a response in other sets of cells; (5)
Neurohormonal signaling- hormones are released into the blood by
neurosecretory neurons. (p.19)
2. How is glucose transported from the blood to the cell? - ANSWER
Pancreatic cells secrete and release insulin to signal muscle cells to absorb
sugar from the blood for energy. (p.3)
3. Understand the transportation of potassium and sodium across plasma
membranes - ANSWER The Na+ -K+ antiport system (Na+ moving out
of the cell and K+ moving into the cell) uses the direct energy of ATP to
move these cations. The transporter protein is the enzyme adenosine
triphosphatase (ATPase). Approximately 60% to 70% of the ATP
synthesized by cells is used to maintain the Na+-K+ transport system. 1,
, three Na+ ions bind to sodium- binding sites on the carrier's interface. 2,
at the same time, an energy- containing adenosine triphosphate molecule
produced by the cell's mitochondria bind to the carrier. The ATP
disassociates, transferring its stored energy to the carrier. 3 and 4, the
carrier then changes shape, releases the three Na+ ions to the outside of
the cell, and attracts two potassium ions to its potassium- binding site. 5,
the carrier then returns to its original shape, releasing the two K+ ions and
the remnant of the ATP molecule to the inside of the cell. The carrier is
now ready for another pumping cycle (p.31)
4. What is active transport? - ANSWER requires life, biologic activity, and
the cell's expenditure of metabolic energy. Unlike passive transport, active
transport occurs across only living membranes that have to drive the flow
"uphill" by coupling it to an energy source (p. 28)
5. What are cytokines? - ANSWER Growth factor, also called cytokines,
stimulate an increase in cell mass or cell growth by promoting the
synthesis of proteins and other macromolecules and inhibiting their
degradation (p. 38)
Cytokines constitute a large family of small-molecular-weight soluble
intracellular-signaling molecules that are secreted, bind to a specific cell
membrane receptors, and regulate innate or adaptive immunity; either
proinflammatory or anti-inflammatory. Majority of important cytokines are
classified as interleukins or interferons (p. 201)
6. Do all cells continue to replicate and divide? - ANSWER No. For
example, most of the neurons and skeletal muscle cells are in a terminally
differentiated G0 state; with their cell cycle control system disassembled,
, the molecular regulatory switches become permanently turned off and
cell division rarely occurs (p. 37)
7. When normal columnar ciliated epithelial cells of the bronchial lining are
replaced by stratified squamous epithelial cells, the process is called? -
ANSWER Bronchial metaplasia (p. 49)
8. What is the relation between ischemia and ATP? - ANSWER An
anaerobic (without oxygen) metabolic pathway can synthesize ATP. This
process called substrate phosphorylation, or anaerobic glycolysis, is linked
to the breakdown (glycolysis) of carbohydrates.... The reactions in
anaerobic glycolysis involve the conversion of glucose to pyruvic acid
(pyruvate) with the simultaneous production of ATP. If oxygen is absent,
pyruvate is converted to lactic acid, which is released into the extracellular
fluid. Elevated lactate level is indicative of tissue hypoxia or low oxygen
concentration (pp.26 & 27)....As lactic acid increases, oxygen decreases
(hypoxia), cell tissues...this is reversible if oxygen is reintroduced...
9. When does sodium enter the cell and cause swelling? - ANSWER A
reduction in ATP levels causes the plasma membrane's sodium-potassium
pump (Na+-K+) and sodium-calcium exchange to fail, which leads to an
intracellular accumulation of sodium and calcium, resulting in cellular
swelling and diffusion of potassium out of the cell (p. 51)
Cellular swelling, the most common degenerative change, is caused by the shift
of extracellular water into the cell. In hypoxic injury, movement of fluid and
ions into the cell is associated with acute failure of metabolism and loss of ATP
production. Normally, the pump that transports sodium ions (Na+) out of the
cell is maintained by the presence of ATP in adenosine triphosphatase
(ATPase), the active transport enzyme. In metabolic failure caused by hypoxia,
, reduced levels of ATP and ATPase permit sodium to accumulate in the cell,
whereas potassium (K+) diffuses outward. The increase of intracellular sodium
concentration increases osmotic pressure, which draws more water into the
cell. The cisternae of the endoplasmic reticulum become distended, rupture,
and coalesce to form large vacuoles that isolate the water from the cytoplasm,
a process called vacuolation. Progressive vacuolation results in cytoplasmic
swelling called oncosis or vacuolar degeneration. If cellular swelling affects all
cells in an organ, the organ increases in weight and becomes distended and
pale. Cellular swelling is reversible and an early manifestation of almost all
types of cellular injury (p.84)
10.What are free radicals in relation to cell damage? Progression of diseases?
- ANSWER A free radical is any molecular species capable of
independent existence that contains a single unpaired electron in an outer
orbit. Having one unpaired electron makes the molecule unstable; The
molecule becomes stabilized either by donating or by accepting an
electron from another molecule. When the attacked molecule loses its
electron, it becomes a free radical. Therefore, it is capable of injurious
chemical bond formation with DNA, RNA, proteins, lipids, and
carbohydrates- many other key molecules in membranes and nucleic
acids. Free radicals are difficult to control and initiate chain reactions.
With low chemical specificity and high reactivity, free radicals can react
with most molecules in their proximity.
An important mechanism of membrane damage is injury induced by free
radicals, especially by a disturbance in the balance between the production of
ROS and antioxidant defenses called oxidative stress. Oxidative stress can be
caused by an increase of different reactive species or depletion of antioxidant
defense, or both, and result in detrimental oxidation of different molecules
including proteins, lipids, nucleic acids, and others. Oxidative stress can
activate several intracellular signaling pathways because ROS can modulate
enzymes and transcription factors. This process is an important mechanism of
Choice and Conceptual Actual Exam Questions
With Reviewed 100% Correct Detailed Answers
Guaranteed Pass!!Current Update
1. What is chemical signaling? - ANSWER Primary means of cell-to-cell
communication. 5 forms of signaling mediated by secreted molecules: (1)
Contact-dependent signaling requires cells to be in close membrane-
membrane contact; (2) Paracrine signaling- cells secrete local chemical
mediators that are quickly absorbed, destroyed, or immobilized; (3)
Autocrine signaling- cells produce signals that they, themselves, respond
to (cancer cells); (4) Hormonal signaling involves specialized endocrine
cells that secrete chemicals called hormones (TSH). Hormones are
released by one set of cells and travel through the tissue and through the
bloodstream to produce a response in other sets of cells; (5)
Neurohormonal signaling- hormones are released into the blood by
neurosecretory neurons. (p.19)
2. How is glucose transported from the blood to the cell? - ANSWER
Pancreatic cells secrete and release insulin to signal muscle cells to absorb
sugar from the blood for energy. (p.3)
3. Understand the transportation of potassium and sodium across plasma
membranes - ANSWER The Na+ -K+ antiport system (Na+ moving out
of the cell and K+ moving into the cell) uses the direct energy of ATP to
move these cations. The transporter protein is the enzyme adenosine
triphosphatase (ATPase). Approximately 60% to 70% of the ATP
synthesized by cells is used to maintain the Na+-K+ transport system. 1,
, three Na+ ions bind to sodium- binding sites on the carrier's interface. 2,
at the same time, an energy- containing adenosine triphosphate molecule
produced by the cell's mitochondria bind to the carrier. The ATP
disassociates, transferring its stored energy to the carrier. 3 and 4, the
carrier then changes shape, releases the three Na+ ions to the outside of
the cell, and attracts two potassium ions to its potassium- binding site. 5,
the carrier then returns to its original shape, releasing the two K+ ions and
the remnant of the ATP molecule to the inside of the cell. The carrier is
now ready for another pumping cycle (p.31)
4. What is active transport? - ANSWER requires life, biologic activity, and
the cell's expenditure of metabolic energy. Unlike passive transport, active
transport occurs across only living membranes that have to drive the flow
"uphill" by coupling it to an energy source (p. 28)
5. What are cytokines? - ANSWER Growth factor, also called cytokines,
stimulate an increase in cell mass or cell growth by promoting the
synthesis of proteins and other macromolecules and inhibiting their
degradation (p. 38)
Cytokines constitute a large family of small-molecular-weight soluble
intracellular-signaling molecules that are secreted, bind to a specific cell
membrane receptors, and regulate innate or adaptive immunity; either
proinflammatory or anti-inflammatory. Majority of important cytokines are
classified as interleukins or interferons (p. 201)
6. Do all cells continue to replicate and divide? - ANSWER No. For
example, most of the neurons and skeletal muscle cells are in a terminally
differentiated G0 state; with their cell cycle control system disassembled,
, the molecular regulatory switches become permanently turned off and
cell division rarely occurs (p. 37)
7. When normal columnar ciliated epithelial cells of the bronchial lining are
replaced by stratified squamous epithelial cells, the process is called? -
ANSWER Bronchial metaplasia (p. 49)
8. What is the relation between ischemia and ATP? - ANSWER An
anaerobic (without oxygen) metabolic pathway can synthesize ATP. This
process called substrate phosphorylation, or anaerobic glycolysis, is linked
to the breakdown (glycolysis) of carbohydrates.... The reactions in
anaerobic glycolysis involve the conversion of glucose to pyruvic acid
(pyruvate) with the simultaneous production of ATP. If oxygen is absent,
pyruvate is converted to lactic acid, which is released into the extracellular
fluid. Elevated lactate level is indicative of tissue hypoxia or low oxygen
concentration (pp.26 & 27)....As lactic acid increases, oxygen decreases
(hypoxia), cell tissues...this is reversible if oxygen is reintroduced...
9. When does sodium enter the cell and cause swelling? - ANSWER A
reduction in ATP levels causes the plasma membrane's sodium-potassium
pump (Na+-K+) and sodium-calcium exchange to fail, which leads to an
intracellular accumulation of sodium and calcium, resulting in cellular
swelling and diffusion of potassium out of the cell (p. 51)
Cellular swelling, the most common degenerative change, is caused by the shift
of extracellular water into the cell. In hypoxic injury, movement of fluid and
ions into the cell is associated with acute failure of metabolism and loss of ATP
production. Normally, the pump that transports sodium ions (Na+) out of the
cell is maintained by the presence of ATP in adenosine triphosphatase
(ATPase), the active transport enzyme. In metabolic failure caused by hypoxia,
, reduced levels of ATP and ATPase permit sodium to accumulate in the cell,
whereas potassium (K+) diffuses outward. The increase of intracellular sodium
concentration increases osmotic pressure, which draws more water into the
cell. The cisternae of the endoplasmic reticulum become distended, rupture,
and coalesce to form large vacuoles that isolate the water from the cytoplasm,
a process called vacuolation. Progressive vacuolation results in cytoplasmic
swelling called oncosis or vacuolar degeneration. If cellular swelling affects all
cells in an organ, the organ increases in weight and becomes distended and
pale. Cellular swelling is reversible and an early manifestation of almost all
types of cellular injury (p.84)
10.What are free radicals in relation to cell damage? Progression of diseases?
- ANSWER A free radical is any molecular species capable of
independent existence that contains a single unpaired electron in an outer
orbit. Having one unpaired electron makes the molecule unstable; The
molecule becomes stabilized either by donating or by accepting an
electron from another molecule. When the attacked molecule loses its
electron, it becomes a free radical. Therefore, it is capable of injurious
chemical bond formation with DNA, RNA, proteins, lipids, and
carbohydrates- many other key molecules in membranes and nucleic
acids. Free radicals are difficult to control and initiate chain reactions.
With low chemical specificity and high reactivity, free radicals can react
with most molecules in their proximity.
An important mechanism of membrane damage is injury induced by free
radicals, especially by a disturbance in the balance between the production of
ROS and antioxidant defenses called oxidative stress. Oxidative stress can be
caused by an increase of different reactive species or depletion of antioxidant
defense, or both, and result in detrimental oxidation of different molecules
including proteins, lipids, nucleic acids, and others. Oxidative stress can
activate several intracellular signaling pathways because ROS can modulate
enzymes and transcription factors. This process is an important mechanism of
