Miss Lee - Osmosis

Question 1

What is osmosis

Answer 1

Osmosis is the net random movement of water molecules from a region of high water potential to region of low water potential (down a water potential gradient) across a partially permeable membrane

Question 2

What kind of process is osmosis

Answer 2

Osmosis is a passive process (no ATP energy is required)

Question 3

What is the water potential of Pure water

Answer 3

Pure water has a bit of water potential of zero

Question 4

When the movement of water goes in and out of the cell what does it change

Answer 4

The movement of water changes the hydrostatic pressure of the cell.

Question 5

What is water potential Measure

Answer 5

What is potential is a measurement of the tendency of water molecules to move across a partially permeable membrane. The symbol of water potential is a great letter for psi (looks like a trident) (measured in KPA) any solution with a negative water potential as a solute in the solution

Question 6

What is in the cell cytoplasm that may have a negative water potential

Answer 6

In the cell cytoplasm it contains dissolved sugars, salts and so the water potential is negative.

Question 7

When a solution has a high water potential what does it mean

Answer 7

A solution with a high water potential has a large number of water molecules that are free to move

Question 8

What factors may affect the rate of water movement

Answer 8

1. The higher the water potential gradient, the faster the rate of osmosis. As osmosis occurs, the difference in water potential either side of the membrane decreases. So the rate of osmosis levels decreases over time
2. Surface area of the exchange surface will have an affect on the rate of osmosis as the greater the surface area of the partially permeable membrane the more area water molecules have to cross the membrane. This therefore increases the rate of osmosis
3. The thickness of the exchange surface Will affect the rate of osmosis as the sin of the exchange surface the shorter the pathway from Mike has had to travel. This therefore increases the rate of osmosis

Question 9

What types of solutions are there

Answer 9

A hiptonic solution is a solution with more water in it then solute, Compared to another solution.
A hypertonic solution is a solution with more solute in it than water, compare to a another solution
A lsotonic solution is to solutions/cells that have the same water potential