What is photosynthesis?
Photosynthesis is the biochemical process by which microalgae and other phototrophic organisms convert light energy into chemical energy stored in organic molecules. From water and carbon dioxide they produce sugars and release oxygen as a by-product.
Light reactions and carbon-fixation phase
Photosynthesis is divided into two stages. In the light reactions, pigments capture light and energy molecules (ATP and NADPH) are generated, with oxygen released from the splitting of water.
In the carbon-fixation phase (Calvin cycle), those energy molecules are used to incorporate CO₂ and form sugars, which are then transformed into proteins, lipids and other compounds.
Pigments and light capture
Microalgae capture light thanks to pigments such as chlorophyll a and b, carotenoids and, in cyanobacteria, phycobiliproteins. These pigments absorb different wavelengths of photosynthetically active radiation (PAR, 400–700 nm), allowing them to use light efficiently.
Importance: oxygen and carbon capture
Thanks to their photosynthetic efficiency and fast growth, microalgae contribute notably to oxygen production and are studied for CO₂ capture and sustainable biomass production.
FAQ
They produce biomass (sugars and, from them, proteins, lipids and other compounds) and release oxygen.
It is photosynthetically active radiation, the band of light (400–700 nm) that microalgae use for photosynthesis.
Sources
- Richmond, A. & Hu, Q. (eds.) (2013). Handbook of Microalgal Culture: Applied Phycology and Biotechnology. Wiley-Blackwell.
- Chisti, Y. (2007). Biodiesel from microalgae. Biotechnology Advances, 25(3), 294–306.
- Spolaore, P. et al. (2006). Commercial applications of microalgae. Journal of Bioscience and Bioengineering, 101(2), 87–96.
- Mata, T.M. et al. (2010). Microalgae for biodiesel production and other applications: A review. Renewable and Sustainable Energy Reviews, 14(1), 217–232.
Scientific outreach based on specialised literature. Scientific review: pending.
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