Concepts in Physiology of Algae and Plants

Research in physiology same as other bra nches of biology needs too many techniques and methods. Most of laboratory equipment and methods are created by the scientists and engineers who are not phy siologist. On the other hand, explanation about most parts of metabolisms of living organisms are involved other filed of sciences. Therefore, scientists wh o work in physiology of algae and plants, rather than b iology of cyanobacteria, red and green algae and plants, will require to learn a range of vocabularies and concepts in chemistry, biochemistry, physics, biop hysics, statistics, mathematics, and even quantum m echanics. Photosynthesis in algae and plants is p erhaps the best possible example of a scientific field that is intrinsically interdisciplinary. Photosynth esis is a process in which light energy is captured by few hundreds of chlorophyll molecules call ed antenna complex. The antenna system does no t do any chemistry; it works by an energy transfer process that involves the migration of electronic exci ted states from one chlorophyll to another and finally to chlorophyll molecules in photosynthetic reaction centres. Then, this energy stored photo-chemically by an organism, and used to drive energy-requiring cellular processes like carbon fixation and carb ohydrate synthesisin chloroplast. While carbon fixation and carbohydrate synthesis involve too many biochemical reactions, light capture and energy transf er process in antenna is a purely physical process. What is light and where does it comes from? How do w e measure light? Light is electromagnetic radiation which emitted from a series of nuclear fusion react ions from Hydrogen to Helium in sun, and like all s tars, produces a broad spectrum of radiation output t hat ranges from gamma rays, visible light to radio waves. Physiologist who are not expert in physics of light, mistakenly measure the light intensity as lux or foot candle units using lux meter which widel y used in photography and is based on sensitivity of eyes. Whereas for photosynthesis in algae and pla nts, rather than quality of light (wave length), the qu antity of light energy, or numbers of photons is needed, which must be measured as micro mole photon per square meter per second using quantum sensor. C apture of light energy occurs in milliseconds to a few femtoseconds and cause the excitation of electron from chlorophyll molecules located in reactio n centres. Excited electron passes through a series of electron accepters and donors. Speed of electron transfer from donor to accepter increase by increasing the temperature, whereas sometimes by decr easing the temperature, which would be explained by classic mechanics and quantum mechanics respec tively. All these confirm that for doing high quality of research in physiology of algae and plant, we need to have at least an elementary understanding of concepts in all relevant fields of sciences.