What organelle is responsible for photosynthesis in plant and algal cells?

The chloroplast is the organelle responsible for photosynthesis in plant and algal cells. This is a crucial function as chloroplasts contain chlorophyll, the pigment that captures light energy from the sun. During photosynthesis, chloroplasts convert carbon dioxide and water into glucose and oxygen, using the light energy captured by chlorophyll. This process not only provides energy for the plants themselves but also generates oxygen, which is essential for most life forms on Earth.

In contrast, mitochondria are primarily involved in cellular respiration, where they convert the energy stored in glucose into ATP, the energy currency of the cell. The nucleus serves as the control center of the cell, housing genetic material and coordinating activities like growth and metabolism, but it does not participate directly in photosynthesis. Ribosomes are the sites of protein synthesis and do not play a role in energy production or conversion processes. Therefore, chloroplasts are uniquely equipped to perform the vital task of photosynthesis, making them essential for energy conversion in plant and algal cells.