Ch 2 Flashcards
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.
A. using the energy in ATP to extrude 3 Na+ out of the cell in exchange for taking 2 K+ into the cell.
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.
D. have variable protein and lipid contents depending on their location in the cell.
Second messengers
A. are substances that interact with rst messengers outside cells.
B. are substances that bind to firrst 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.
D. mediate the intracellular responses to many different hormones and neurotransmitters.
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.
B. is an organelle that participates in posttranslational processing of proteins
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.
C. refers to the invagination of the plasma membrane to uptake extracellular contents into the cell
G-protein–coupled receptors
A. are intracellular membrane proteins that help regulate movement within the cell.
B. are plasma membrane proteins that couple the extracellular binding of primary signaling molecules to exocytosis.
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.
C. are plasma membrane proteins that couple the extracellular binding of primary signaling molecules to the activation of heterotrimeric G-proteins
Gap junctions are intercellular connections that
A. primarily serve to keep cells separated and allow for transport 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.
B. serve as a regulated cytoplasmic bridge for sharing of small molecules between cells
F-actin is a component of the cellular cytoskeleton that
A. provides a structural component for cell movement.
B. is de ned as the “functional” form of actin in the cell.
C. refers to the actin subunits that provide the molecular
building blocks of the extended actin molecules found in
the cell.
D. provides the molecular architecture for cell to cell
communication.
A. provides a structural component for cell movement.
