THE INFLUENCE OF LIGHT AND CARBON DIOXIDE ON PHOTOSYNTHESIS.
THE INFLUENCE OF LIGHT AND CARBON DIOXIDE ON PHOTOSYNTHESIS.
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DOI：
10.1085/jgp.20.6.807
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发表时间：
1937-07-20
期刊：
影响因子：
--
通讯作者：
Smith EL
中科院分区：
文献类型：
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作者：
Smith EL
1.本文描述了一个光学系统，它在瓦尔堡压力容器底部反射282，000米烛光的光强。有了这样高的强度，它是可能的，以测量光合作用的水盾草的单叶在一个大范围的强度和CO2浓度。2.所获得的数据用方程KI = p/（p2 max.）- 其中p是在光强度I下的光合作用速率，K是将曲线定位在I轴上的常数，并且p max.是光合作用的最大速率用CO2浓度代替I，该方程描述了Cabomba的光合作用数据，作为CO2浓度的函数。3.上述方程还描述了其他研究者获得的光合作用作为强度函数的数据，以及外部扩散速率不是限制因素的CO2浓度。这表明不同种类的绿色植物在动力学性质上有基本的相似性，因此可能在化学机理上也有相似性。4.上述方程的推导可以根据半阶光化学反应和布莱克曼反应进行，其中强度和CO2浓度作为一次幂进入，或者如果方程的两边都是平方，则光化学反应和布莱克曼反应是一阶反应，强度和CO2作为平方进入。分数指数或强度的平方的存在表明一个复杂的反应机制，涉及一个以上的光化学反应。这与还原一个CO2分子所需的4个量子是一致的。
1. An optical system is described which furnishes an intensity of 282,000 meter candles at the bottom of a Warburg manometric vessel. With such a high intensity available it was possible to measure the rate of photosynthesis of single fronds of Cabomba caroliniana over a large range of intensities and CO2 concentrations. 2. The data obtained are described with high precision by the equation KI = p/(p 2 max. – p 2)½ where p is the rate of photosynthesis at light intensity I, K is a constant which locates the curve on the I axis, and p max. is the asymptotic maximum rate of photosynthesis. With CO2 concentration substituted for I, this equation describes the data of photosynthesis for Cabomba, as a function of CO2 concentration. 3. The above equation also describes the data obtained by other investigators for photosynthesis as a function of intensity, and of CO2 concentration where external diffusion rate is not the limiting factor. This shows that for different species of green plants there is a fundamental similarity in kinetic properties and therefore probably in chemical mechanism. 4. A derivation of the above equation can be made in terms of half-order photochemical and Blackman reactions, with intensity and CO2 concentration entering as the first power, or if both sides of the equation are squared, the photochemical and Blackman reactions are first order and intensity and CO2 enter as the square. The presence of fractional exponents or intensity as the square suggests a complex reaction mechanism involving more than one photochemical reaction. This is consistent with the requirement of 4 quanta for the reduction of a CO2 molecule.