CHAPTER 2Overview of Cellular Physiology in Medical Physiology 61MULTIPLE-CHOICE QUESTIONS
For all questions, select the single best answer unless otherwise directed.
- The electrogenic Na, K ATPase plays a critical role in cellular
physiology by
A) using the energy in ATP to extrude 3 Na+ out of the cell in
exchange for taking two K+ into the cell.
B) using the energy in ATP to extrude 3 K+ out of the cell in
exchange for taking two Na+ into the cell.
C) using the energy in moving Na+ into the cell or K+ outside
the cell to make ATP.
D) using the energy in moving Na+ outside of the cell or K+
inside the cell to make ATP. - Cell membranes
A) contain relatively few protein molecules.
B) contain many carbohydrate molecules.
C) are freely permeable to electrolytes but not to proteins.
D) have variable protein and lipid contents depending on their
location in the cell.
E) have a stable composition throughout the life of the cell. - Second messengers
A) are substances that interact with first messengers outside
cells.
B) are substances that bind to first messengers in the cell
membrane.
C) are hormones secreted by cells in response to stimulation
by another hormone.
D) mediate the intracellular responses to many different
hormones and neurotransmitters.
E) are not formed in the brain. - The Golgi complex
A) is an organelle that participates in the breakdown of proteins
and lipids.
B) is an organelle that participates in posttranslational
processing of proteins.
C) is an organelle that participates in energy production.
D) is an organelle that participates in transcription and
translation.
E) is a subcellular compartment that stores proteins for
trafficking to the nucleus.
5. Endocytosis
A) includes phagocytosis and pinocytosis, but not clathrin-
mediated or caveolae-dependent uptake of extracellular
contents.
B) refers to the merging of an intracellular vesicle with the
plasma membrane to deliver intracellular contents to the
extracellular milieu.
C) refers to the invagination of the plasma membrane to uptake
extracellular contents into the cell.
D) refers to vesicular trafficking between Golgi stacks.
6. G protein-coupled receptors
A) are intracellular membrane proteins that help to regulate
movement within the cell.
B) are plasma membrane proteins that couple the extracellular
binding of primary signaling molecules to activation of
small G proteins.
C) are plasma membrane proteins that couple the extracellular
binding of primary signaling molecules to the activation of
heterotrimeric G proteins.
D) are intracellular proteins that couple the binding of primary
messenger molecules with transcription.
7. Gap junctions are intercellular connections that
A) primarily serve to keep cells separated and allow for trans-
port across a tissue barrier.
B) serve as a regulated cytoplasmic bridge for sharing of small
molecules between cells.
C) serve as a barrier to prevent protein movement within the
cellular membrane.
D) are cellular components for constitutive exocytosis that
occurs between adjacent cells.
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Kandel ER, Schwartz JH, Jessell TM (editors): Principles of Neural
Science, 4th ed. McGraw-Hill, 2000.
Pollard TD, Earnshaw WC: Cell Biology, 2nd ed. Saunders, Elsevier,
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Sperelakis N (editor): Cell Physiology Sourcebook, 3rd ed. Academic
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