Study Guide

Photosynthesis In the Real World

  • Politics

    In principle, photosynthesis research seems like a relatively nonpolitical subject. However, in reality, it is an integral part of recent science policy debates. Photosynthesis and science policy intersect in two main ways. First of all, much of the scientific research on photosynthesis that occurs in this country depends on government money. Secondly, photosynthesis research is a part of a recent political movement to transform our energy system.

    Investing in green energy is a political movement that is not gaining momentum fast enough in the United States. China is now the largest producer of solar panels,blank" href="http://i.livescience.com/images/i/14826/i02/science-research-development-federal-funding-infographic-110214g-02.jpg?1297732456">science research. While such comparisons are exciting, some are worried about what will happen when the relatively slow pace of scientific research fails to yield a golden nugget by election time.

  • Pop Culture

    Many superheroes call on science to describe where they find their superhuman powers. For Spiderman, a spider transferred its DNA to Peter. For Superman, his powers came from exposure to the Earth’s Sun. Sound familiar? Well, OK. Maybe photosynthesis didn’t make it into the Superman plot line, but we think it should have. What’s that you’re saying? We can see you shaking your head. Photosynthesis is cool enough, darnit. Yes, we insist. What if we told you that a super-Spidey exists in Nature?

    Look at the super slug Elysia chlorotica. It eats plants, steals their DNA, and keeps their chloroplasts. The result? After a two-week feast, it can survive for the rest of its year life living only on the energy produced from photosynthesis. That is like Spiderman and Superman all wrapped into one sluggy superparty! It is a shame that your stomach enzymes are so well-adapted to breaking down chloroplasts and DNA.

  • History

    In the 1600s, Jan Van Helmont made a reasonable hypothesis. He gathered that, in order for a tree to grow and gain mass, it must obtain food from somewhere else. He carefully weighed a tree and the soil that the he wanted to plant the tree in. Time passed, and the tree grew. After five years, he reweighed the tree, which had grown quite large, and then…wait for it…he weighed the soil. To his surprise, the soil weighed basically the same amount every day. Jan concluded that the tree must have gained the nutrients from the water that he had added over the years.

    Jan was partially correct: water, as well as carbon dioxide and light, are required for photosynthesis. About 100 years later, another Jan, Jan Ingen-Housz, demonstrated that plants, well actually, only the green parts like the stems and leaves, could manufacture oxygen by using the Sun’s light and not its heat. Furthermore, Jan #2 proposed the novel idea that plants used carbon dioxide (CO2) while producing oxygen (O2).prizes/chemistry/laureates/index.html">Source

  • Research

    While scientists have made major advancements in photosynthetic research over the last century, we still have a somewhat incomplete picture of the whole process. Slackers! Scientists would like to get a better idea of how photosynthesis is regulated. For example, we would like to know (yes, we at Shmoop would like to know) how an organism might change its light-harvesting abilities based on what is happening in its environment. Furthermore, while we have gained snapshots into the protein complexes that mediate photosynthesis, we would like to be able to watch photosynthesis happen on a microscopic level. Live. Advancements in microscopy techniques are beginning to make some of these wild and crazy dreams a distinct possibility.

    Besides being a cool biological process, scientists study photosynthesis for two important reasons. For one, Photosystem I is considered to be the most efficient light-driven, energy-creating machine in Nature. One thing that you have probably learned from the oil industry is that energy = $$$...$...$. Many scientists are trying to either artificially mimic photosynthesis to generate energy or are trying to exploit photosynthetic organisms as energy producers.

    How can scientists exploit photosynthetic organisms to generate compounds that we can use as fuel? One big step has been the sequencing of genomes (sets of encoded genetic information) of many photosynthetic organisms. These sequenced genomes allow scientists to more easily compare the different photosynthetic machinery in different organisms. Furthermore, knowing the sequence makes it easier when they try to modify the genomes of these organisms.

    Why would scientists want to modify the genomes of organisms that have evolved over millions of years to perfect photosynthesis? Because, they are crazy and crave massive failure. Just kidding. The reason is that, while these organisms have evolved to better fit into their own environments, these evolved traits are not necessarily the best traits for generating fuel for humans. It's always about us, isn't it? Scientists can look for mutants that have useful changes in particular photosynthetic pathways, or they can try to create changes themselves by a wide variety of molecular and genetic techniques. In one instance, scientists have been able to generate mutants in the algae C. reinhardtii that have a defect in electron transfer around Photosystem I.

    Current research on photosynthesis has the potential to substantially change the way that we as humans live. Imagine a world where cheap and efficient energy was the standard for everyone. Cheap fuel would sure make road trips (or even flying!) more affordable. The possibilities are endless…if only it would help you buy your own set of wheels!