What does it mean to move against, down an electrochemical gradient?

Question

What does it mean to move against, down an electrochemical gradient?

Answer 1

I think, a movements of particles, esp fr the charged ones like ions tend to move down it's electrochemical gradient. Electrochemical gradient here is a difference of cumulative charge caused by 'gathering' of particular charged particles. For example in human nerve cells, it's more positive in the outside than inside, it's caused by accumulation of more positively charged sodium ion in the outside. Those sodium ions will spontaneously move into the nerve cell down an electrochemical gradient. Therefore, to restore the normal conditions, nerve cells have to pump those ions back to the outside against an electrochemical gradient. These action isn't a spontaneous reaction, so energy in form of ATP is required for the cell to perform this.

Answer 2

describes the movement of particles. if  a particle moves against an electrochemical gradient, energy or ATP will be needed in order to fuel the movement and is known as active transportation. the use of carrier proteins may also be needed to help transport the particle.

if it moves down the electrochemical gradient, then passive transport is occuring where ATP is not needed to make it happen...

electrochemical gradients are usually created when ions (think sodium, and potassium) are transported. they carry an electrical charge so when they change their position, lets say from outside a celll to inside of it, the electrical charge of both inside and outside the cell will change.this creates the electrochemical gradient that molecules either move against or with