Chapter 10, Problem 11PIAT

Can green algae replace “black gold”?

Over the past decade, there has been great interest in developing a sustainable and renewable energy source that would displace our dependence on fossil fuels. Photosynthetic organisms, like the microalgae being cultured in the image above, are currently being used to produce bioethanol, biodiesel, and bio-H₂. How are photosynthetic organisms being engineered to promote the production of these biofuels?

Aquatic plants and algae carry out photosynthesis using the same light reactions and Calvin cycle as in land plants. Would you expect any of these organisms to also require the C₄ pathway? Describe the problem that is solved by the C₄ pathway in land plants and if this could ever be an issue in an aquatic environment.