7.7 Flashcards
Electrical Gradient
Differences in charges between molecules across a plasma membrane
Membrane Potential
Electric potential difference between a cell membrane
Active Transport
A cell expending energy in order to move substances across concentration or electrochemical gradients
Primary active Transport
Active transport that expends energy by using ATP
Secondary active Transport
Uses energy from electrochemical gradients to move cells instead of ATP
Common features of Primary active transport
-Proteins that change shape in order to move large molecules and ions across the lipid bilayer
-These proteins move the molecules and ios against the concentration gradient
-Energy from splitting ATP is used for this pump operation
6 Steps of sodium-potassium pump
- The pump is open inside of the cell and attracts sodium ions. Up to 3 a trip.
- The sodium ions collected trigger ATP to be broken down and ADP is released. A phosphate group is also attached to the pump.
- The pump changes shape and is open outside of the cell. The sodium ions are released.
4.The pump collects 2 potassium ions. This triggers the phosphate group to be released. - The pump turns back into its original form facing open inside of the cell.
6.The pump releases the potassium ions into the cell.
How the sodium-potassium pump generates a membrane potential
Because the pump creates a large amount of potassium in the cell, which causes more to move back out and the gradient stays the same.
Co transporter
A carrier protein that transports multiple substances at the same time without needing to ever change forms.
antiporter
Two kinds of molecules being moved using a cotransporter, moving in opposite directions
symporter
Two kinds of molecules being moved using a contransporter, moving in the same direction
How does active transport complications cause cystic fibrosis?
The chlorine ion channel doesnt work properly, which means that water does not move through those areas well enough either. Because of this mucus builds up.
