PSIO 201 Block 5.1-5.2 quiz

How can ions enter/exit cells (move across a plasma membrane)?

• they can move directly through the membrane

• ions can use a channel protein

• ions can use a carrier protein

Concentration of ______ is high outside of the cell.

Concentration of ______ is high inside the cell.

A difference in concentration on either side of the plasma membrane is known as an ion ______.

What is the result of the Na+/K+ ATPase (pump)?

• 3 Na+ ions to ECF

  2 K+ ions to ICF

• 3 Na+ ions to ICF

  2 K+ ions to ICF

• 3 Na+ ions to ECF

  2 K+ ions to ECF

• 3 Na+ ions to ICF

  2 K+ ions to ECF

The plasma membrane is permeable to K+ ions due to potassium ______ channels.

Movement of K+ ions is influenced by which two competing forces?

• -into cell following concentration gradient

  – out of cell following electrical ‘gradient’

• -Out of cell following concentration gradient

  – Into cell following electrical ‘gradient’

The competing forces seen in the previous slide cause a charge separation (a buildup of potential energy) across the membrane. This potential energy is stored in a living cell at rest. This is known as resting ______ ______.

How can we change the membrane potential? We can do this by changing membrane permeability. This causes changes in ion movement, which then can cause changes in ___ ___.

What will happen if K+ channels are opened?

• K+ moves out of the cell

• K+ enters the cell

• K+ doesn't move in either direction

• K+ channels will never be opened