BCMB 311 Exam Questions with Verified Correct
Answer
Electrochemical gradient
The combined effect of a concentration gradient and an electrical gradient on an ion
Concentration gradient
The difference in concentration of a substance across a membrane
Membrane potential
The electrical voltage difference across a membrane
Na+ concentration gradient
Na+ is much more concentrated outside animal cells, favoring Na+ movement into the cell
K+ concentration gradient
K+ is much more concentrated inside animal cells, favoring K+ movement out of the cell
Na+ electrochemical gradient
Both concentration and electrical forces generally favor Na+ movement into the cell
K+ electrochemical gradient
Concentration favors K+ movement out while the negative membrane potential favors K+
movement in
Resting membrane potential
The negative electrical potential inside a resting animal cell
, K+ leak channel
A channel that allows K+ to diffuse out of the cell and contributes to the negative resting
membrane potential
Na+/K+ pump
ATP-powered pump that moves 3 Na+ out and 2 K+ into the cell per ATP
Na+/K+ pump function
Maintains low intracellular Na+ and high intracellular K+ concentrations
Uniport
Transport of one type of solute
Symport
Transport of two solutes in the same direction
Antiport
Transport of two solutes in opposite directions
Channel
Membrane protein that forms a hydrophilic pore through which specific ions or molecules can
pass
Transporter
Membrane protein that specifically recognizes a substrate and changes conformation to transport
it
Answer
Electrochemical gradient
The combined effect of a concentration gradient and an electrical gradient on an ion
Concentration gradient
The difference in concentration of a substance across a membrane
Membrane potential
The electrical voltage difference across a membrane
Na+ concentration gradient
Na+ is much more concentrated outside animal cells, favoring Na+ movement into the cell
K+ concentration gradient
K+ is much more concentrated inside animal cells, favoring K+ movement out of the cell
Na+ electrochemical gradient
Both concentration and electrical forces generally favor Na+ movement into the cell
K+ electrochemical gradient
Concentration favors K+ movement out while the negative membrane potential favors K+
movement in
Resting membrane potential
The negative electrical potential inside a resting animal cell
, K+ leak channel
A channel that allows K+ to diffuse out of the cell and contributes to the negative resting
membrane potential
Na+/K+ pump
ATP-powered pump that moves 3 Na+ out and 2 K+ into the cell per ATP
Na+/K+ pump function
Maintains low intracellular Na+ and high intracellular K+ concentrations
Uniport
Transport of one type of solute
Symport
Transport of two solutes in the same direction
Antiport
Transport of two solutes in opposite directions
Channel
Membrane protein that forms a hydrophilic pore through which specific ions or molecules can
pass
Transporter
Membrane protein that specifically recognizes a substrate and changes conformation to transport
it
