PHOTORESPIRATION Meaning and
Definition
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Photorespiration is a metabolic process that occurs in various plant species, especially in C3 plants, wherein oxygen uptake and carbon dioxide release takes place in the presence of light. It is an inefficient and wasteful process that competes with photosynthesis for the same substrate, creating a problem for the plant's ability to fix carbon dioxide.
During photorespiration, when the stomata of a plant open to facilitate the intake of carbon dioxide, water vapor is also lost through transpiration. However, in circumstances where there is a high concentration of oxygen and a low concentration of carbon dioxide, the enzyme RuBisCO, responsible for carbon fixation, mistakenly attaches oxygen molecules to the RuBP substrate instead of carbon dioxide. This leads to the formation of a toxic compound known as phosphoglycolate.
To overcome the negative impacts of photorespiration, plants undergo a complex series of reactions called the photorespiratory pathway. This pathway aims to convert phosphoglycolate into a usable form for the plant by converting it back into a metabolically useful compound, such as 3-phosphoglycerate, through a series of reactions across chloroplasts, peroxisomes, and mitochondria. These reactions consume energy and carbon dioxide while producing carbon dioxide, ammonia, and reducing equivalents.
Overall, photorespiration has detrimental effects on plants as it consumes valuable energy and reduces the efficiency of carbon fixation. It limits plant growth and photosynthetic output and poses a particular challenge under conditions where oxygen levels are high and carbon dioxide levels are low, such as in hot and arid environments.
Common Misspellings for PHOTORESPIRATION
- ohotorespiration
- lhotorespiration
- -hotorespiration
- 0hotorespiration
- pgotorespiration
- pbotorespiration
- pnotorespiration
- pjotorespiration
- puotorespiration
- pyotorespiration
- phitorespiration
- phktorespiration
- phltorespiration
- phptorespiration
- ph0torespiration
- ph9torespiration
- phororespiration
- phoforespiration
- phogorespiration
- phoyorespiration
Etymology of PHOTORESPIRATION
The word "photorespiration" is derived from two separate words: "photo" and "respiration".
1. "Photo" comes from the Greek word "phos" (φῶς), which means "light". In scientific terminology, "photo-" is often used to refer to anything related to light or light-based processes.
2. "Respiration" comes from the Latin word "respiratio", which means "breathing". In biology, respiration refers to the process of converting energy stored in organic compounds (such as glucose) into usable energy for the cells of an organism. It involves the intake of oxygen and the release of carbon dioxide.
Therefore, "photorespiration" combines these two terms to refer to a specific metabolic process that occurs in plants, where respiration is modified by light.
