Lectures: 1 session / week, 2 hours / session
The biological conversion of solar energy to chemical energy forms the basis of life as we know it. Knowledge of this fundamental process is critical to our understanding of the biogeochemical cycles that mitigate global warming. In this course, you will journey through the web of physical, chemical, and biological reactions that collectively constitute photosynthesis. We will begin with light harvesting and follow photons to the sites of primary photochemistry: the photoreaction centers. A molecular-scale view will show in atomic detail how these protein complexes capture and energize electrons. Then we will follow the multiple pathways electrons take as they carry out their work. Consequent reactions, such as the synthesis of ATP and the reduction of CO2 during the synthesis of carbohydrates, will also be discussed in structural detail. Lastly, we will delve into the evolution of these systems and also discuss other photosynthetic strategies, such as light-driven proton pumps and anoxygenic photosynthesis. The course will include a visit to an electron microscope to allow students to directly observe proteins involved in photosynthesis.
During the typical class session, we will analyze two papers in a discussion-based format. Everyone should read both papers before class, and each student should be prepared to raise and answer questions. At the beginning of each class, we will have a question and answer period in which the instructors and the rest of the class will respond to any specific questions that the students may have thought of while reading the articles. We will spend the remainder of the class discussing the data presented in the article by analyzing each figure and table and the resulting conclusions. Each class will conclude with a brief outline of the following session class by the instructors.
Students are expected to attend every class meeting and turn in all assignments on time on the date they are assigned. The major focus will be on discussion and interpretation of scientific papers, so student attendance and participation is essential. Other than Ses #1, there will be no lectures and students should come to class prepared to participate in a discussion of the assigned papers. Missing a class should occur only in extreme circumstances. If a student knows he/she must miss a class, he/she must contact the instructor in advance and receive permission for the absence. Students who have been allowed an excused absence will be asked to complete a written assignment concerning the papers discussed during the missed class session.
There are no exams. The class has a pass/fail grading system. There will be two two-page written assignments and a project. The first assignment will be a project and will involve creating a graphic representation of a protein involved in photosynthesis using 3D-structural coordinates from the Protein Data Bank (PDB). The goal of your protein modeling is to highlight and visually present a feature of the protein important to its function. Protein illustrations should be completed in class in Ses #4. For the second assignment, students will be given an abstract from a scientific paper and will be asked to design a set of experiments that would support the conclusions presented in it. This assignment will be due by 5:00 pm in Ses #6. The final assignment will coincide with an oral presentation and will involve presenting an original research proposal to the rest of the class followed by a critique. Students should contact the instructors to discuss ideas and topics. The written research proposal should be handed in before 5:00 pm in Ses #12. Students will be expected to rewrite their proposals incorporating any changes deemed necessary by the instructors and hand-in rewritten documents at the final class meeting. The proposal presentations will take place in class in Ses #15.
As the goal of this course is to familiarize students with the reading and critical evaluation of the primary literature (research papers) in the field of photosynthesis, students are expected to have completed 7.03, 7.05, 7.06 or 7.08.