Osmosis

Question 1

Osmosis

Answer 1

The diffusion of water across a selectively permeable membrane from a high water potential to a low water potential.

Question 2

Water potential (simplified)

Answer 2

The likelihood of water molecules diffusing

Question 3

What factors would result in the fastest rate of osmosis?

Answer 3

• High water potential
• High surface area
• Thin membrane

Question 4

What factors would result in the slowest rate of osmosis?

Answer 4

• Low water potential
• Small surface area
• Thick membrane

Question 5

Isotonic point

Answer 5

Where water has not moved into or out of the tissue as the water potential is the same inside the cells as the solution is outside.

Question 6

What are the stages involved in identifying water potential of plant cells?

Answer 6

1. Cut and weigh the potato pieces
2. Place chips in boiling tubes with different sucrose concentrations
3. Dry the chips and weigh again to record change in mass
4. Plot a graph and identify the isotonic point

Question 7

Water potential Ѱ

Answer 7

Ѱ is a measure of the pressure created by water molecules. It describes the extent to which water is able to move from a solution (to another.)

Question 8

What is Water potential measured in?

Answer 8

KPa

Question 9

What water potential value does pure water have?

Answer 9

0. This is the highest possible water potential

Question 10

Note about water potential

Answer 10

the more negative the number the lower the water potential.

Question 11

“During osmosis, water molecules only move in one direction across the bilayer: from a high water potential to a low water potential.”

Is this statement true or false?

Answer 11

False

Question 12

If a cell is placed in an isotonic solution, which side of the membrane has a higher water potential?

Answer 12

Each side of the membrane will be the same

Question 13

Water potential volume.

Answer 13

The greater the number of water molecules in a given volume, the higher (less negative) the value of water potential.