Raheel Anwar, 2012, Ecology and Evolutionary Biology

This summer I worked with the phytoplankton algae Thalassiosira weissflogii (TW) in order to study how the changing global environment, with increasing carbon dioxide concentrations, is affecting algae, the powerhouses of the ocean. TW cells are important because they are able to use a special enzyme called cadmium carbonic anhydrase (CDCA) to convert carbon dioxide into bicarbonate and vice versa. Higher carbon dioxide concentrations in the oceans, due to anthropogenic greenhouse gas emissions, result in a more acidic ocean (lower pH levels). Over the summer I did experiments to determine how these changes in pH and hence, carbon dioxide levels, affect the CDCA enzyme. I learned that higher pH levels (8.0+) mean a higher expression of the enzyme, while lower levels (7.7) result in a much lower expression of the enzyme. Another part of my research this summer was to try to isolate TW chloroplasts as a whole organelle without significant residual cell debris in order to see whether the CA enzyme was located in or outside of it. Over the summer I was able to accomplish this goal and have observed so far that CA activity does not seem to occur in the isolate but does occur in a whole cell solution.