The light-dependent reactions of photosynthesis take place in the:

1. A chloroplast has two very different internal compartments. 2. The membranes stacked inside it hold the pigment complexes. 3. The light-dependent reactions occur in the thylakoid membranes of chloroplasts. 4. The Calvin cycle occurs in the stroma of chloroplasts instead. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 8 'Photosynthesis', sections 8.1-8.3_