A temperature-dependent integrated kinetics for the overall process of photosynthesis in green plants is discussed. The C₄ plants are chosen and in these plants, the rate of photosynthesis does not depend on the partial pressure of O₂. Using some basic concepts like chemical equilibrium or steady state approximation, a simplified scheme is developed for both light and dark reactions. The light reaction rate per reaction center ($R'_1$) in thylakoid membrane is related to the rate of exciton transfer between chlorophyll neighbours and an expression is formulated for the light reaction rate $R'_1$. A relation between $R'_1$ and the NADPH formation rate is established. The relation takes care of the survival probability of the membrane. The CO₂ saturation probability in bundle sheath is also taken into consideration. The photochemical efficiency (𝜙) is expressed in terms of these probabilities. The rate of glucose production is given by $R_{\text{glucose}} = (8/3)(R'_1v_L)\phi(T)g(T)$ ([G3P]/[$P_i$]$^2_{\text{leaf}}$)$_{SS}$Q$_{\text{G3P} \rightarrow \text{glucose}}$ where 𝑔 is the activity quotient of the involved enzymes, and G3P represent glycealdehyde-3-phosphate in steady state. A Gaussian distribution for temperaturedependence and a sigmoid function for de-activation are incorporated through the quotient 𝑔. In general, the probabilities are given by sigmoid curves. The corresponding parameters can be easily determined. The theoretically determined temperature-dependence of photochemical efficiency and glucose production rate agree well with the experimental ones, thereby validating the formalism.

The rate of glucose equivalent production in C₄ green plants is investigated as a function of the intercellular partial pressure of CO₂, so as to find the precise physical chemistry of photosynthesis. Expressions are first formulated for the dependence of photochemical efficiency and of rubisco activation on pressure. Then a pressure-dependent rate law is derived. The latter is successfully tested for two specific C₄ plants, namely, Panicum antidotale and Panicum coloratum.