Osmosis and Diffusion

These flashcards cover key vocabulary and concepts related to osmosis and diffusion as presented in the lecture notes.

Diffusion

The movement of a solute from an area of high concentration to an area of low concentration.

Simple diffusion

The diffusion of a molecule directly through the membrane phospholipids; only hydrophobic solutes can cross.

Hydrophobic

Referring to substances that do not interact well with water; hydrophobic solutes can pass through the hydrophobic cell membrane.

Channel proteins

Proteins in the cell membrane that form tunnels to allow solutes to pass through.

Facilitated diffusion

The movement of solutes across a membrane from high to low concentration through a channel protein, requiring no energy.

Active transport

The movement of solutes from low to high concentration across a membrane, requiring energy.

Endocytosis

A process that brings solute molecules into a cell by bending the membrane inward to form a vesicle.

Exocytosis

A process that brings solute molecules out of a cell by a vesicle fusing with the cell membrane.

Osmosis

The movement of water across a cell membrane towards the side with the highest solute concentration.

Hypertonic solution

A solution with a higher solute concentration than a cell, causing cells to lose water and shrink.

Hypotonic solution

A solution with a lower solute concentration than a cell, causing cells to gain water and enlarge.

Isotonic solution

A solution with an equal solute concentration to a cell, resulting in no net movement of water.

Penetrating solute

A solute that can diffuse across a membrane, such as hydrophobic solutes or hydrophilic solutes with specific transport proteins.

Non-penetrating solute

A solute that cannot diffuse across a membrane, typically hydrophilic solutes without transport proteins.

Intracellular compartment

The region inside all the cells of the body containing about 30 liters of fluid.

Extracellular compartment

The region outside the cells of the body, consisting of blood plasma and tissue fluid.