Exam 1 Rated 100%!!!
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,What chemical component of the plasma membrane prevents ions from readily and freely
moving across the membrane? - ANS Lipids (phospholipids)
Where is the concentration of [K+] greater? - ANS In the cytoplasm
A
Across a cell's plasma membrane, movemen of water is a ___________ event. - ANS
Passive through a channel.
R
Where is the concentration of [Na+] greater? - ANS In the extracellular fluid.
For a neutrally charged molecule, "Active" transport means the molecules move across a
membrane from? - ANS A low concentration to a higher concentration.
U
What molecule is the source of energy for primary active transport to occur? - ANS
(adenosine triphosphate)
ATP
LA
True of False: There is only one type of channel in cell membranes. - ANS False.
True or False: Regarding primary active transport, solutes move from a compartment of low
concentration to a compartment of high concentration. - ANS True. Always low to high.
C
True or False: Regarding secondary active transport of glucose, the movement of glucose is
from a compartment of high concentration to a compartment of low concentration. - ANS
False.
O
True or False: All transport through membrane channels is classified "Active" transport. - ANS
False.
D
True or False: Electrolytes are pumped and leaked across cell membranes simultaneously but
independently. - ANS True.
At what point in time does the electrochemical equilibrium potential exist? - ANS At
equilibrium.
What major factor that regulates an electrolyte's electrochemical equilibrium potential across a
cell membrane? - ANS Concentration (chemical) gradient.
, True or False: The electrochemical equilibrium potential for a single highly permant ion species
is controlled by the concentration gradient. - ANS True.
True or False: Movement of a charge electrolyte is determined by the major forces of voltage
plus chemical concentration gradients. - ANS True.
True or False: The cellular K+ Electrochemical Equilibrium Potential is regulated by
concentration differences across the plasma membranes. - ANS True.
Which of these ion choices is primarily responsible for establishing a typical cell membrane's
resting potential?
A
A. Mg++
B. Na+
C. K+ - ANS K+
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True or False: Excessive extracellular acid (i.e. [H+]) will raise the concentration of extracellular
potassium ion concentration. - ANS True.
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True or False: Cell Membrane Potential is controlled by the relative degree of ion permeability
as well as ion concentration gradients existing across a cell's plasma membrane. - ANS
True.
LA
True or False: Rhabdomyolysis can lead to cardiac muscle cell pathology as the result of
creating a condition of hyperkalemia (excessive K+ concentration in the plasma). - ANS
True.
True or False: A normal lean person consists of 90% water. - ANS False, 60% water.
C
True or False: Most of the sodium in the body is inside the cells. - ANS False, it is
extracellular. K+ is intracellular.
O
True or False: The capillary is the main barrier between the intracellular and extracellular fluids.
- ANS False. The cell wall, also called the plasma membrane, separates ICF and ECF. The
capillary separates the interstitium and the plasma which are both subcompartments of the ECF.
D
True or False: To measure the volume of the entire extracellular fluid compartment, we use a
substance that moves freely across the capillary but cannot enter the cell. - ANS True. An
example is insulin.
True or False: Water and small solutes move across the capillary wall by active transport. - ANS
False. All movement across the capillary wall is PASSIVE. Driven only by hydrostatic and colloid
osmotic (oncotic) pressures.