Question
What drives the "direction" of osmosis? In
other words, why does water have a net flow
and move one way or the other across a
membrane?
• The solute concentration difference when
comparing two areas separated by a
membrane. Water will accumulate in the area
with more solutes.
• The cohesion of water molecules. Water will
accumulate based on hydrogen bonding to the
amphipathic phospholipids.
• Active transport of water molecules. Protein
pumps pump water towards the hypertonic
solution.
O Osmosis is the movement of water from a
hypertonic solution to a hypotonic solution.
• Water tends to be repelled by other water
molecules and forced across the membrane.
Answer
Osmosis is driven by the solute concentration difference, the cohesion of water molecules, active transport of water molecules, and the tendency of water to be repelled by other water molecules.