<p>The cellular aspects of microbial metabolism can be targeted to alter and redesign the cellular processes for enhanced production of desired compounds. An understanding into the energetics of photosynthesis and its mechanism can be used to considerably enhance photosynthetic productivity together with increased efficiency of utilization of solar energy. Some of the structural aspects include expansion of solar absorption spectra through reduction of light harvesting complex, increase in the flux of electrons transferred through the electron transport chain, increase in the plastoquinone pool size, and increase in levels of Cyt b₆f complexes. Herein, we analyze the factors affecting carbon metabolism and its conversion into biomass within the cell. The kinetic and thermodynamic limitations of carbon capture and fixation are explored to favor a photosynthetically efficient system. The study discusses the enhancement of photosynthetic productivity of microalgae through structural modifications of the photosynthetic unit for the efficient utilization of solar energy. A comprehensive understanding of the kinetic and thermodynamic limitations of the cellular processes affecting biomass production in microalgae can be worked out for building an energy-efficient multi-product process system.</p>