Chapter 1: Diffusion and Osmosis (Vocabulary)

Vocabulary flashcards covering diffusion, permeability, barriers, and osmosis concepts from the notes.

Diffusion

Passive movement of solutes from high concentration to low concentration, down a concentration gradient, with no energy input.

Concentration gradient

The difference in the amount of solute between two areas; the driving force for diffusion.

Passive transport

Movement of substances across a medium or membrane without using cellular energy.

Physical barrier

A structure that blocks or slows the movement of substances (e.g., a closed door blocking scent).

Permeability

How easily a barrier allows substances to pass; can be permeable or impermeable.

Permeable

Able to pass through a barrier.

Impermeable

Not able to pass through a barrier.

Facilitated diffusion

Passive transport of solutes across a cell membrane using carrier proteins, without energy input, limited by gradient and protein availability.

Carrier proteins

Membrane proteins that help move specific solutes (like glucose) across the membrane during facilitated diffusion.

Glucose transport

Movement or transfer of glucose into or around cells via carrier proteins (an example of facilitated diffusion).

Osmosis

Diffusion of water across a selectively permeable membrane from higher water concentration to lower water concentration.

Hypotonic

A solution with higher water concentration (lower solute) outside the cell; water enters the cell, causing it to swell.

Hypertonic

A solution with higher solute concentration outside the cell; water leaves the cell, causing it to shrink.

Isotonic

A solution with the same solute concentration as the inside of the cell; no net water movement and the cell remains stable.

Water permeability

The ease with which water can cross a barrier or membrane (often via channels), enabling osmosis.