What's the difference between respiration and photosynthesis?

Photosynthesis and respiration have opposing functions, but complement each other in plants. Photosynthesis synthesizes glucose (using energy from sunlight) by taking up CO₂ from the atmosphere and producing the by-product O₂. Respiration breaks down glucose to release energy in the form of ATP, utilizing oxygen (O₂) and releasing carbon dioxide (CO₂) continuously. Photosynthesis takes place in chloroplasts while respiration occurs in mitochondria, with the two processes having opposite metabolic ends, as (in day-night cycles in plants) photosynthesis takes place during the day-time and respiration all the time.

These processes create an interdependent cycle of energy. Photosynthesis produces glucose and oxygen, which are used by respiration. Respiration produces CO₂ and water, which are utilized by photosynthesis. The balanced exchange maintains the level of atmospheric gases. This interdependence is evident in healthy forests, which act as carbon regulators.

Environmental factors play distinct roles in each of these processes, causing photosynthesis to cease completely in darkness, respiration to continue and slow down in cold, dry weather partially, and both gas exchanges to be prevented by the closing of the stomata in drought. Therefore, gardeners strive to create optimal conditions by providing adequate light availability and ensuring soil aeration.

Recognizing these discrepancies can explain plant behaviors! Wilting occurs when a plant is respiring faster than it can photosynthesize during stress. The CAM plants have a developed mechanism to separate these processes during the day and night, which helps improve water efficiency. Knowing all of this informs agricultural practices and climate modeling.

Read the full article: Respiration in Plants: The Complete Process Guide