Osmosis

What is osmosis?

The net movement of water from an area of high water potential to an area of low water potential, through a partially-permeable membrane

Similarities between diffusion and osmosis

Both are passive processes that do not require energy

Both move down a concentration gradient

Compare and contrast how water and ions enter cells.

Comparison: both move down a concentration gradient, both move through protein channels in cell membranes (polar molecules)

Contrast: ions can move against a concentration gradient by active transport

Highest water potential possible? And what happens when you add solutes to it?

Pure water has a 0Ψ

When solute is added to a solution, the solution becomes more negative (becomes more concentrated)

When investigating osmosis, why is blotting the potato required before weighing?

Water will affect the mass, we only want to measure the water taken up or lost by the potato.