Final answer:
Photosynthesis occurs in the chloroplasts of plant and algal cells, specifically within the thylakoid membranes where chlorophyll captures light energy, leading to the production of ATP and NADPH.
Step-by-step explanation:
The process of photosynthesis takes place in the chloroplasts. These are specialized organelles found in plant cells and certain algal cells. Chloroplasts are unique in hosting the complex biochemical processes of photosynthesis.
Chloroplasts possess a double membrane system, consisting of an outer and an inner membrane. Inside these membranes is the stroma, a fluid-filled space where the Calvin cycle of photosynthesis occurs. Suspended within the stroma are structures known as thylakoids, which are organized into stacks called grana. The thylakoids contain the pigment chlorophyll, vital for capturing light energy. The light-dependent reactions take place on the thylakoid membranes, where sunlight is converted into chemical energy in the form of ATP and NADPH.
Summarizing, the entire process begins when chlorophyll absorbs light energy, then through a series of reactions, converts this energy into a chemical form that can be used by the plant to create glucose from carbon dioxide and water.