Osmoregulation & Water Potential

These flashcards cover important vocabulary related to osmoregulation and water potential, including definitions and key concepts from the lecture notes.

Osmoregulation

The process by which organisms maintain the balance of water and solutes in their bodies to ensure stable internal conditions, or homeostasis.

Water Potential

A measure of the potential energy of water in a system that determines the direction in which water will move.

Pressure Potential

The physical pressure exerted on the water within a plant cell, representing the effect of physical pressure on water movement.

Solute Potential

Measures the effect of dissolved solutes on the movement of water; it represents the decrease in water potential that results from the presence of solutes.

Turgor Pressure

The pressure exerted by fluid in a cell that pushes the cell membrane against the cell wall, helping to maintain the cell’s structure.

Hypotonic Solution

A solution where the concentration of solutes is lower outside the cell than inside, causing water to flow into the cell.

Hypertonic Solution

A solution where the concentration of solutes is higher outside the cell than inside, causing water to flow out of the cell.

Isotonic Solution

A solution where the concentration of solutes is the same inside and outside the cell, resulting in no net movement of water.

Water Movement

Water moves from areas of higher water potential to areas of lower water potential.

RELEVANT EQUATION (Water Potential)

Water Potential (Ψ) = Pressure Potential (ΨP) + Solute Potential (ΨS).

Ionization Constant (for sucrose)

The ionization constant (i) for sucrose is 1, meaning sucrose does not dissociate into ions in solution.

Pressure Constant (R)

The pressure constant (R) is 0.0831 L•bars/mol•K.

Temperature in Kelvin

Temperature in Kelvin is calculated by adding 273 to the Celsius temperature.