It has been decided in a town in northwest Alaska that environmental protection should be prioritized. A team of engineers has therefore been hired to help them out. Roxy, the leader of the project, will take you on a journey over the sea and show you that the most problematic facilities are the coal power plant and the fish farm. To mitigate the problem, she has come up with the brilliant idea to produce biofuel from algae using the excess of nutrients from the fish farm and the heat and CO2 from the coal plant.

Extract pigments from algae

When scuba diving, Roxy found some mysterious dark algae, and now she needs your help to figure out if they have pigments that can absorb green light. Most plants are green, so they reflect this colour and absorb other wavelengths, which they use for photosynthesis. However, green is a major component of the visible light spectrum, so combining algae that use green light with algae that use other wavelengths maximises the use of sunlight. In this simulation, you will extract pigments from algae using different solvents and measure their absorbance spectra.

Where are the pigments?

When you get to the lab, Dr. One, your virtual lab assistant, has already prepared a selection of different fractions from the mysterious algae Roxy brought. Since you are interested in obtaining pigments, you need to choose the correct one. Nuclear fraction? Or perhaps chloroplasts? In case you don’t know and pick the wrong one, you can have another go. This is a virtual lab, meaning you can make as many mistakes as you need to get it right!

What solvents to use?

Most pigments, such as chlorophyll, are hydrophobic. However, some have different conjugated systems that make them chemically diverse. Since your aim is to extract all the pigments from the dark algae, you must think carefully about what types of solvents you need to use in order to do that.

Can the dark algae absorb green light?

Once you’ve done a series of centrifugations and used liquid nitrogen to snap freeze the pigments, it’s time to find out if the pigment extracts can absorb green light. For that, you will obtain and analyze the absorption spectra using a spectrophotometer. Will these algae hold the key to producing biofuel from pollutants and maximizing the use of the visible light spectrum?