NPB 101 EXAM 1 QUESTIONS & ANSWERS
Glycolysis - Answers -yields 2 molecules of ATP for each molecule of glucose
processed.
membrane proteins - Answers --they serve as channels.
- they serve as carriers.
-they serve as receptor sites.
-they serve as membrane-bound enzymes.
cell volume would increase.
-water wants to even out concentrations inside /outside the cell
-the high concentration inside and low concentration outside the cell , thus water comes
into the cell to dilute the sucrose. - Answers -Osmosis occurs when water diffuses
down its concentration gradient. Given that the plasma membrane of cells is permeable
to water (because there are water channels in the membrane), what would be the effect
of decreasing the extracellular concentration of a non-permeable sugar such as
sucrose?
an increase in the thickness of the membrane - Answers -According to Fick's law of
diffusion, which would decrease the rate of net diffusion of a substance across a
membrane?
-leak channels.
-pumps - Answers -Which protein(s) is/are responsible for development of the resting
membrane potential?
pumps - Answers -maintains the concentration gradient
leak channels - Answers -allows charges to flow across
with the binding sites of both ions exposed to the intracellular fluid, phosphorylation
increases the binding affinity to Na+ and decreases the binding affinity to K+.
-move Na+ out and K+ in intercellular - Answers -The Na+/K+ ATPase is a
transmembrane protein that transports Na+ and K+ ions against their concentration
gradients. The conformation of the protein and its binding affinities for Na+ and K+ are
determined by the state of intracellular phosphorylation. Which effect of phosphorylation
or dephosphory- lation can best account for the active transport of Na+ and K+ ions
across the PM (plasma membrane)?
The electrical gradient for K+ - Answers --favors its movement into the cell at resting
potential.
Glycolysis - Answers -yields 2 molecules of ATP for each molecule of glucose
processed.
membrane proteins - Answers --they serve as channels.
- they serve as carriers.
-they serve as receptor sites.
-they serve as membrane-bound enzymes.
cell volume would increase.
-water wants to even out concentrations inside /outside the cell
-the high concentration inside and low concentration outside the cell , thus water comes
into the cell to dilute the sucrose. - Answers -Osmosis occurs when water diffuses
down its concentration gradient. Given that the plasma membrane of cells is permeable
to water (because there are water channels in the membrane), what would be the effect
of decreasing the extracellular concentration of a non-permeable sugar such as
sucrose?
an increase in the thickness of the membrane - Answers -According to Fick's law of
diffusion, which would decrease the rate of net diffusion of a substance across a
membrane?
-leak channels.
-pumps - Answers -Which protein(s) is/are responsible for development of the resting
membrane potential?
pumps - Answers -maintains the concentration gradient
leak channels - Answers -allows charges to flow across
with the binding sites of both ions exposed to the intracellular fluid, phosphorylation
increases the binding affinity to Na+ and decreases the binding affinity to K+.
-move Na+ out and K+ in intercellular - Answers -The Na+/K+ ATPase is a
transmembrane protein that transports Na+ and K+ ions against their concentration
gradients. The conformation of the protein and its binding affinities for Na+ and K+ are
determined by the state of intracellular phosphorylation. Which effect of phosphorylation
or dephosphory- lation can best account for the active transport of Na+ and K+ ions
across the PM (plasma membrane)?
The electrical gradient for K+ - Answers --favors its movement into the cell at resting
potential.
