Home > Preview
The flashcards below were created by user
on FreezingBlue Flashcards.
Explain the concentration gradients across cells at rest.
- Usually, the inside of a cell membrane holds a more negative charge at rest because of the high concentration of Potassium (K+) ions in comparisson to the outside.
- There is a higher concentration of Sodium and Calcium outside the cell membrane.
Describe permeability differences across cell membrane at rest.
When a cell is at rest, most of the protien channels within the membrane are closed. However, there are occasional potassium channels that remain open, allowing K+ ions to flow freely in and out of the membrane.
What is the purpose and action of Na-K ATPase pumps?
- To restore the "normal" concentration gradient within cells
- These pumps constantly pump 3Na+ ions out & 2K+ ions inside the cell which contributes to the general overall more negative inner charge.
What is the biggest reason why the inside of the cell has a negative charge compared to the outside?
The presence of Protien anions (Pr-) within the ICF greatly contributes to the negative inner charge.
Which ion is about 10,000 times more concentrated outside the cell membrane in the ECF?
Cell membranes at rest are more permeable to which ion? and by how much?
Membranes at rest are 40x more permeable to K+ ions compared to Na+ ions, becaus they have more "open leakage channels" for potassium.
Why is the Resting Membrane Potential -70mV value?
The actual value reflects which ion is mostly moving across the membrane at any given time. (Which happens to be K+)
What is the equillibrium potential for K+?
What is the equillibrium potential for Na+?
Inside verses outside the cell becomes LESS NEGATIVE.
Inside verses outside the cell becomes MORE NEGATIVE.
Returning to the resting membrane potential from either direction.
What would you like to do?
Home > Flashcards > Print Preview