“We make a living by what we get, but we make a life by what we give.” – Winston Churchill
Set Your Priorities
Monday, December 23, 2013
Membrane Transport Proteins
Membrane proteins facilitate the movement of molecules across the membrane.
This pump uses the energy provided by ATP hydrolysis to transport sodium and potassium ions across the membrane.
Active transport requires the input of energy, whereas passive transport is primarily driven by the gradient.Active transport requires energy, whereas passive transport does not.
The GLUT-1 transporter assists the diffusion of glucose through the membrane.
Ions tend to move toward regions of unlike charge.
The sodium-potassium pump maintains a state in which the concentration of sodium is low inside the cell relative to the outside and the concentration of potassium is high inside the cell relative to the outside; thus, three sodium ions are pumped out of the cell and two potassium ions are pumped into the cell against the electrochemical gradient.
Under these conditions, lactose moves against its concentration gradient, so its transport will require energy.