Proteins Associated with Membrane Transport Flashcards
Passive transport
Diffusion and osmosis
Facilitated transport
Typically involves channels like uniporters.
What is the delta energy for passive and facilitated transport?
Negative
What is the delta G for active transport?
Positive
What is the total delta G for active transport?
Negative
Active transport
The action of using pumps (P-type ATPases) or coupled transporters (antiporters or symporters) to transport molecules across membranes.
What do potassium channels do?
Transport potassium
What are the types of potassium channels?
Calcium-activated, inward rectifying, tandem pore, and voltage-gated.
How many monomers form potassium channels?
Four
What is the selectivity filter in potassium channels?
It’s a narrow pore lined with carbonyl groups that ONLY allow potassium to pass through.
What happens if too much calcium gets into the cell?
Known as calcium overload where apoptosis occurs (cell death).
What can carbonyl atoms donate?
Two free electron pairs
What happens when a potassium ion goes in the channel?
There is a coordination of the potassium ion (positive) and the electron pairs of the carbon atoms.
How does potassium exist in an aqueous environment?
Water surrounds (hexagon) the potassium ion to coagulate it.
Desolvation energy
The energy to strip off water molecules attached to ions.
