Osmosis vs Tonicity

Question 1

Define osmosis

Answer 1

Osmosis is the process by which water molecules pass through asemipermeable membrane,from aless concentratedsolution into a more concentrated one.

Question 2

What is the difference between osmosis and diffusion?

Answer 2

Diffusion is the net movement of solute from regions of high solute concentration to regions of low solute concentration, down the concentration gradient.

Question 3

What is osmotic equilibirum?

Answer 3

When the concentrations are equal on both sides of the membrane.

Results in zero osmotic pressure a no force needed to prevent any flow.

Tonicity is the same on both sides of the membrane.

Question 4

How can osmotic equilbirum be reached?

Answer 4

By water moving freely between the cells and extracellular fluid as there is no water barriers through the membrane.

Question 5

How does water move from passive osmotic transport?

Answer 5

Through aquaporins

Question 6

What is osmotic pressure?

Answer 6

The force that is applied to oppose the increase in volume when a membrane is only water and not solute permeable.

This force reduced the volume, to make is equal on both sides.

Question 7

Define tonicity

Answer 7

Number of non-penetrating particles in a solution.

Question 8

What does osmolarity measure?

Answer 8

Osmolarity measures the concentration of biological solutions in specific units called, osmoles.

Question 9

What is the osmolarity of the normal human plasma?

Answer 9

285mOsmol/l (rounded to 300)

Same within the cells as there is no water barrier so they have to be the same inside and outside the cell

Question 10

What is an osmotic flux?

Answer 10

When a solute can’t cross the membrane causing the net movement in water in one direction

Question 11

What are non-penetrating solutes?

Answer 11

The non-penetrating solutes include sodium and chlorine ions in the extracellular fluid and potassium ions in the intercellular fluid.

Question 12

What is the volume of the cell dependent on?

Answer 12

Balance between intracellular osmolarity and extracellular tonicity

Question 13

What is an isometric solution?

Answer 13

Same total number of solute particles as the normal extracellular fluid plasma compartment has.

Question 14

What is a hypo-osmotic solution?

Answer 14

A hypo-osmotic solution has fewer total solute particles

Question 15

What is a hyper-osmotic solution?

Answer 15

A hyper-osmotic solution has a greater number of total particles.

Question 16

What is an isotonic solution?

Answer 16

An isotonic solution has the same number of non-penetrating particles as the normal extracellular fluid plasma compartment has.

Question 17

What is a hypotonic solution?

Answer 17

A hypotonic solution has fewer non-penetrating particles.

Question 18

What is a hypertonic solution?

Answer 18

A hypertonic solution has a greater number of non-penetrating particles.

Question 19

What do non-penetrating particles and penetrating particles determine?

Answer 19

• Non-penetrating particles determine tonicity, and non-penetrating particles are ions.
• Penetrating particles (urea) and non-penetrating particles determine osmolarity.

Question 20

What happens if a cell is in a hypotonic solution?

Answer 20

If a cell is in a hypotonic solution, the water moves down the chemical gradient, into the cell, causing it to swell and eventually burst.

Question 21

What is intravascular haemolysis?

Answer 21

Destruction of red blood cells in the circulation with the release of cell contents into the plasma

Question 22

What happens if a cell is in a hypertonic solution?

Answer 22

If a cell is in a hypertonic solution, water leaves the cell, down the chemical gradient and causes the cell to shrivel and shrink.