Hyperosmotic vs hypoosmotic
publish date: 2023/08/09 09:06:00 GMT+10
volume_mute- When a cell is in a medium with a higher concentration of osmotically active dissolved or colloidal particles, rendering a higher osmotic pressure. In such a situation, water moves across the cell membrane into the medium that is (also called hypertonic) relative to the solution inside the cell.
- When a cell is in a medium with a lower concentration of osmotically active dissolved or colloidal particles, and the solution thus has a lower osmotic pressure than that inside the cell, the cell is said to be in a medium that is (or hypotonic) relative to it, so water moves into the cell.
Correct Answer
Explanation
To avoid confusion, one should be careful to note the point of reference of these terms. For instance, when the internal environment of a cell has a higher concentration of osmotically active particles than the external medium, this means the medium inside the cell is hyperosmotic relative to the external environment. Either way one chooses to state it, the water still moves from the hypoosmotic environment into the hyperosmotic environment. Water moves from where the osmotic pressure is low to where the osmotic pressure is high (to where there are more osmotically active particles). If this process is allowed to continue, all things being equal, the solutions on either side of the semipermeable membrane should eventually become isosmotic to each other.
If particulate matter is poured into one of the two previously isosmotic solutions, and the particles dissolve into the solution, then the equilibrium will be upset and the osmotic pressure that now exists between the two sides will be unequal. Water will move from the area of lower concentration of dissolved molecules.
Reference
Biology: A self-teaching guide