2.1) The site for the light phase of photosynthesis is the thylakoid membranes within the chloroplast.

3.2.2) During the dark phase (Calvin cycle) of photosynthesis, carbon dioxide ($\text{CO}_2$) is fixed by the enzyme RuBisCO and incorporated into an organic molecule (RuBP). This process, called carbon fixation, is essential for synthesizing glucose and other organic compounds, using the ATP and NADPH produced during the light phase.