![]() 53% (in the 400–700 nm range) → 30% of photons are lost due to incomplete absorption, leaving.100% sunlight → non-bioavailable photons waste is 47%, leaving.35–45% of the glucose is consumed by the leaf in the processes of dark and photo respiration.68% of the used energy is lost in conversion into d- glucose.24% of the absorbed photon energy is lost due to degrading short wavelength photons to the 700 nm energy level.30% of the in-band photons are lost due to incomplete absorption or photons hitting components other than chloroplasts.47% lost due to photons outside the 400–700 nm active range (chlorophyll uses photons between 400 and 700 nm, extracting the energy of one 700 nm photon from each one).Starting with the solar spectrum falling on a leaf, The following is a breakdown of the energetics of the photosynthesis process from Photosynthesis by Hall and Rao: Quoted values sunlight-to-biomass efficiency Energy can be dissipated as heat ( non-photochemical quenching), or emitted as chlorophyll fluorescence. If photosynthesis is inefficient, excess light energy must be dissipated to avoid damaging the photosynthetic apparatus. In actuality, however, plants do not absorb all incoming sunlight (due to reflection, respiration requirements of photosynthesis and the need for optimal solar radiation levels) and do not convert all harvested energy into biomass, which results in a maximum overall photosynthetic efficiency of 3 to 6% of total solar radiation. ![]() For actual sunlight, where only 45% of the light is in the photosynthetically active wavelength range, the theoretical maximum efficiency of solar energy conversion is approximately 11%. Using longer wavelengths means less light energy is needed for the same number of photons and therefore for the same amount of photosynthesis. However, photosynthesis can occur with light up to wavelength 720 nm so long as there is also light at wavelengths below 680 nm to keep Photosystem II operating (see Chlorophyll). The Gibbs free energy for converting a mole of CO 2 to glucose is 114 kcal, whereas eight moles of photons of wavelength 600 nm contains 381 kcal, giving a nominal efficiency of 30%. It takes eight (or perhaps ten or more ) photons to use one molecule of CO 2. The value of the photosynthetic efficiency is dependent on how light energy is defined – it depends on whether we count only the light that is absorbed, and on what kind of light is used (see Photosynthetically active radiation). Where C 6H 12O 6 is glucose (which is subsequently transformed into other sugars, starches, cellulose, lignin, and so forth). Photosynthesis can be described by the simplified chemical reactionĦ H 2O + 6 CO 2 + energy → C 6H 12O 6 + 6 O 2 The photosynthetic efficiency is the fraction of light energy converted into chemical energy during photosynthesis in green plants and algae. Fraction of light energy converted into chemical energy during photosynthesis in plants and algae
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |