The process of turning a gaseous chemical into a condensed, more usable state is known as fixation.
Example 1:
Carbon is found as carbon dioxide in the atmosphere. Photosynthesis is the process through which plants convert atmospheric into carbohydrates.
Example 2:
Diatomic nitrogen is an extremely stable yet inactive molecule. Fixing nitrogen into usable chemicals takes a lot of energy, and it happens through atmospheric, biological, and industrial processes. Blue-green algae and nitrogen-fixing bacteria found on the roots of leguminous plants participate in the biological process of atmospheric fixation. A group of enzymes in root bacteria enables the fixation of by reducing it to and . Other soil bacteria's enzymes accelerate the oxidation of to and , which the plants can then decrease to generate proteins. Animals can generate their own protein from nitrogen already fixed in plant proteins and excrete nitrogenous waste as urea by eating plants.