What are two important passive processes for membrane transport?

Answer 1

Diffusion is a method of natural movement of gas molecules from a region of higher concentration to a region of lower concentration. The difference in concentration is called a concentration gradient.

Osmosis is the diffusion of water through a biological membrane. Water molecules move along the concentration gradient from the area of higher water concentration to lower concentration.

Facilitated diffusion is when proteins within the cell carry or escort certain materials or substances in or out of the cell.

Answer 2

Passive transport processes do not require ATP or energy for transport. Co-transport processes would also not be considered a passive process.

-The xylem in plants uses capillary action, a passive process

-If a specific channel exists for, let's say, an ion or molecule, then that channel uses passive transport, however, it the channel cannot be "gated" in any way as in voltage-gated Na+ channels or delayed rectifier K+ channels. You can also look at the ascending loop of Henle in the juxtamedullary nephron of the kidney and see passive transport of water molecules

-The blood brain barrier also allows passive transport of certain molecules

A good way to think of passive transport is whether or not the plasma membrane has "holes" big enough in it to allow for molecules to pass through, provided there are no charge hindrances for that molecule passing through. Or a specific channel is open and letting a molecule in without the expense of ATP (using ATP to make the membrane channel protein does not fall under this category)

Answer 3

What types of amino acids would be found in the different areas of the protein?

Answer 4

Those that require no energy. Osmosis, diffusion, etc.

Answer 5

Passive membrane transport processes include ________.

Answer 6

Diffusion and filtration