Osmosis and Osmoregulation

Flashcards covering key terms and concepts related to osmosis, tonicity, and osmoregulation.

Osmosis

The diffusion of water across a semipermeable membrane.

Solute

Substance dissolved in a solution.

Tonicity

The ability of a surrounding solution to cause a cell to gain or lose water.

Isotonic

A solution with the same concentration of solutes as the cell, resulting in no net movement of water.

Hypertonic

A solution with a higher concentration of solutes than the cell, causing water to move out of the cell.

Hypotonic

A solution with a lower concentration of solutes than the cell, leading water to move into the cell.

Osmotic Pressure

The pressure required to prevent water from moving across a semipermeable membrane.

Water Potential

The potential energy of water in a system, combining solute potential and pressure potential.

Stenohaline

Organisms that cannot tolerate substantial changes in external osmolarity.

Euryhaline

Organisms that can survive large fluctuations in external osmolarity.

Direction of water during Osmosis?

From low solute concentration to high solute concentration

What drives the movement of water across a membrane

A concentration gradient

How does the water concentration gradient compare to the solute gradient

It is the opposite of the solute gradient

What determines Tonicity

The concentration of non-permeable solutes relative to the cell.

How does osmolarity affect water movement

Water moves toward the solution with higher osmolarity.

What is the formula for water potential

ψ = ψs + ψp

Solute Potential (ψs)

The effect of solutes on water potential (always negative).

Pressure potential (ψp)

Physical pressure on a solution (can be positive or negative).

Animal Cells prefer?

Isotonic environments

Homeostasis

Maintaining a stable internal environment.

Regulator

An organism that controls internal conditions despite environmental changes.

Conformer

An organism whose internal conditions change with the environment.

Osmoregulation

Balancing water and solute levels in an organism.