菌紫质在强光和弱光依次照射下的特性分析

Characteristics analysis of bacteriorhodopsin under irradiation of strong and weak light in turn

为了研究菌紫质在强光和弱光依次照射下的特性,根据菌紫质的光循环建立其简化的能级图和速率方程,求解速率方程,得到最重要、寿命最长的上能级上的相对分子数浓度及其变化规律。结果表明:在强光照射下上能态■上的相对分子数浓度随时间延长而趋于饱和,随照射光强增大其上升速度越快,停止强光照射之后逐渐衰减返回基态;用弱光照射菌紫质时,上能态■上的分子数浓度受强光照射后的慢衰减和弱光照射引起增加的影响,随着时间延长,上能态■上的相对分子数浓度主要受弱光照射影响。人眼杆细胞中主要成分是视紫红质,它的分子结构、特性与菌紫质的基本一致,研究结果可用于解释人眼的暗适应特性。

Characteristics of bacteriorhodopsin under strong and weak light irradiation were studied and analyzed.The simplified energy level diagram and rate equations were established based on the photocycle of bacteriorhodopsin,and the molecule number concentration and its variation rule of the most important and longest lifetime at upper-energy state were obtained by solving the rate equations.It was found that the molecular number concentration at the upper-energy state ■ under the srong light irradiation tended to saturation with time,the rate of rise was faster as the increase of light intensity,and it gradually returned to ground state after the strong light was stopped.When the bacteriorhodopsin was irradiated with weak light at once,the molecule number concentration at the upper-energy state ■ was affected by the slow attenuation after the strong light irradiation and the increase caused by the weak light irradiation.With the extension of time,the molecule number concentratio at upper-energy state ■ was mainly affected by weak light irradiation.The main component of human eye’s rod cells is rhodopsin,and its molecular structure and characteristics are basically the same as those of bacteriorhodopsin.The results of the study could be used to explain the dark adaptation characteristics of human eyes.