Diffusion
The passive movement of molecules from an area of high concentration to low concentration.
Definition
Diffusion is the net passive movement of particles (atoms, ions, or molecules) from a region of higher concentration to a region of lower concentration down a concentration gradient, driven by the random thermal motion of particles. No energy input is required. Diffusion is a fundamental transport mechanism in biology, governing the movement of gases in lungs, nutrients across cell membranes, and neurotransmitters across synapses.
Example
“Oxygen inhaled into the lungs diffuses from the high-oxygen air in the alveoli across the thin alveolar membrane into the low-oxygen blood in surrounding capillaries, while carbon dioxide simultaneously diffuses in the reverse direction to be exhaled.”
Usage Examples
- 1
“The team applied diffusion best practices to improve their biology outcomes significantly.”
- 2
“Understanding diffusion is essential for anyone building a career in STEM.”
When & How to Use
Use 'Diffusion' when working in Biology contexts where diffusion is the net passive movement of particles (atoms, ions, or molecules) from a region of higher concentration to a region of lower concentration down a concentration gradient, driven by the random thermal motion of particles.
- ▸Applying diffusion principles during a biology project or initiative
- ▸Explaining diffusion to a junior team member or stakeholder unfamiliar with STEM
- ▸Evaluating options or proposals using diffusion as a decision-making criterion
Etymology & Origin
The term 'Diffusion' derives from professional usage and entered STEM professional usage as the field formalised in the 20th century.
History & Evolution
The concept of diffusion has evolved alongside STEM. Early practitioners relied on informal methods; structured approaches emerged with the professionalisation of biology in the mid-20th century. Today, diffusion is a standard part of STEM practice globally.
Synonyms
- passive transport
- concentration gradient movement
- Fickian diffusion
Antonyms / Opposites
- active transport
- osmosis
Images
CC-licensed · free to useVideo
Related Terms
- Osmosis
- Cell Transport
- Concentration Gradient
- Membrane Permeability