What is respiration in plants?
Written by
Paul Reynolds
Reviewed by
Prof. Martin Thorne, Ph.D.Plant respiration is the continuous biochemical process in which cells break down glucose to produce energy. This occurs continuously, night and day, in every living tissue of the plant. There is a continual intake of oxygen into the cells and an emission of carbon dioxide. This metabolic machine provides the energy required for the necessities of life, such as growth and food absorption. Both aerobic (with oxygen) and anaerobic (without oxygen) processes provide the energy conversion described in this section.
Aerobic Process
- Requires oxygen to produce maximum energy yield
- Generates 36 ATP molecules per glucose molecule
- Occurs in plant mitochondria during normal conditions
- Releases carbon dioxide and water as byproducts
Anaerobic Adaptation
- Activates when oxygen drops below critical levels
- Produces only 2 ATP molecules per glucose
- Creates ethanol and CO₂ as metabolic outputs
- Common in waterlogged roots or flooded soils
Respiration is distinct from photosynthesis in that photosynthesis is the process by which sugars are built up in the presence of sunlight during the day. Respiration breaks down sugars for energy throughout the day and night. Plants must maintain this balance to survive. The exchange of gases occurs through specialized structures for this purpose. Stomata and root hairs are used to allow the intake of oxygen and expulsion of carbon dioxide.
Temperature has a great effect on the rate of respiration. The Q<sub>10</sub> coefficient indicates that the rates double for a 10°C rise in temperature. The availability of oxygen determines the energy efficiency of respiration. For them to function optimally, root systems require well-aerated soil. Gardeners monitor these items to ensure the health of the plants. Respiration is also tied to the global carbon cycle.
Read the full article: Respiration in Plants: The Complete Process Guide
