Photosynthesis is an astonishing natural process that consists of two steps: (a) the conversion of light energy into chemical energy and (b) the fixation of carbon from the atmosphere. My research focuses on the first process, specifically on a protein complex named photosystem I in the model alga Chlamydomonas reinhardtii. We aim to better understand the role of specific proteins within photosystem I, which we try to achieve by knocking out these proteins individually. Afterwards, the physiological effects of the missing protein are measured by pulse-amplitude modulated (PAM) fluorometry.