Rev. Virtual Quim. |Vol 7| |No. 1| |56-73| 56 ArtigoAspectos Fisiológicos e Ambientais da Fotossíntese Kluge, R. A.;* Tezotto-Uliana, J. V.; da Silva, P. P. M. Rev. Virtual Quim., 2015, 7 (1), 56-73. Data de publicação na Web: 30 de novembro de 2014 http://www.uff.br/rvq Physiological and Environmental Aspects of PhotosynthesisAbstract: Undoubtedly, photosynthesis is one of the most important process for the life planet maintenance. The sun releases radiant energy that is able to boost the photosynthetic apparatus of the plants, which produce carbohydrates that will be used in the respiration. Among the most important reactions of photosynthesis is the release of oxygen, essential for respiration, which happens in photosystem II. The products generated in the first phase of photosynthesis or photochemical phase (ATP and NADPH) are used in the second phase or the carbon fixation phase. In this second phase acts the Rubisco enzyme, the key enzyme of photosynthesis for the production of carbohydrates such as starch and sucrose. Several factors interfere in the photosynthesis, such as temperature, oxygen and carbon dioxide content, light level, water availability and others. The knowledge of these interferences has aided in the development of technologies to maximize agricultural productivity and enable agroclimatic zoning of many cultures.Keywords: Sunlight; photosystem; radiation; Calvin-Benson cycle; rubisco. ResumoA fotossíntese é sem dúvidas um dos processos mais importantes para a manutenção da vida no planeta. O sol, através da liberação de sua energia radiante, é capaz de impulsionar o aparato fotossintético das plantas e produzir carboidratos que serão utilizados no processo respiratório. Dentre as reações mais importantes da fotossíntese está a liberação de oxigênio, imprescindível para a respiração, que ocorre no fotossistema II. Os produtos gerados na primeira fase da fotossíntese, ou fase fotoquímica (NADPH e ATP) são usados na segunda fase ou fase de fixação de carbono. Nessa segunda fase atua a enzima Rubisco, a principal enzima da fotossíntese, para a produção de carboidratos, como amido e sacarose. Vários fatores interferem na fotossíntese, como temperatura, teores de oxigênio e de gás carbônico, nível de luminosidade, disponibilidade hídrica, entre outros. O conhecimento de suas interferências tem auxiliado no desenvolvimento de tecnologias para maximizar a produtividade agrícola e possibilitar o zoneamento agroclimático de muitas culturas.Palavras-chave: Luz solar; fotossistema; radiação; ciclo de Calvin-Benson; rubisco. * U ive sidade de "ão Paulo, Es ola "upe io de Ag i ultu a Luiz de Quei oz , Depa ta e to

Food irradiation is the most studied and evaluated worldwide treatments. The term radiation refers to the physical phenomenon in which radiant energy moves through the space or matter in the form of electromagnetic waves, such as microwave, infrared, ultraviolet, X-rays and gamma rays. In foods, the most commonly used technique relies on irradiation using a specific band of electromagnetic energy radiation known as ionizing radiation with gamma rays. The purpose is to sterilize or reduce decay, disinfect vegetables from insects and parasites, delay fruit ripening and inhibit sprouting roots. However, as all technological process, irradiation has disadvantages. It can be said that, as the other postharvest technologies, the use of gamma radiation results in advantages and quality to fruits and vegetables since applied correctly and at the right moment. Current legislation and the specific requirement of the species and cultivar must be respect. If these caution are taken, the use of irradiation results in healthy and safe products without quality degradation and without postharvest losses.