Plant respiration is the opposite of photosynthesis, which is a biological process performed by green plants that creates oxygen and releases it into the air. During respiration, plants absorb free molecules of oxygen (O2) and use them to create water, carbon dioxide, and energy, which helps the plant grow.
Chemical Equation for Plant Respiration
The chemical formula for plant respiration is C6H12O6 + 6 O2 => 6 CO2 + 6 H2O + Energy.
Plant respiration uses plant food in the form of carbohydrates, and oxygen that is already present in the atmosphere to produce carbon dioxide and water. A small amount of energy is also produced during this process.
Respiration Occurs in Plants and Animals
Respiration is a common biological process that also occurs in animals. We commonly refer to respiration as "breathing." Scientifically speaking, respiration is an event during which oxygen is added to a complex carbohydrate molecule to create water, carbon dioxide, and a release of energy.
A plant needs to be able to use as much of the energy that is produced during respiration as possible in order to survive. Water and carbon dioxide are almost always present in the micro-environment of the plant, so these compounds may be released into the air.
Respiration is considered an oxidation process because it involves complex molecules of starches and carbohydrates combining with oxygen to produce new compounds and energy. Oxidation occurs when a molecule gains an atom of oxygen, which changes its chemical composition.
When Respiration Occurs
Respiration, unlike photosynthesis, does not use energy from the sun. Therefore, respiration can occur in darkness. During respiration plants reuse the sugars, or carbohydrates, already stored within the plant to help it grow.