Chloroplasts are organelles in plants and algae with a specialised role in photosynthesis. These organelles contain pigment chlorophyll which captures the energy of sunlight. In a series of chemical reactions in chloroplasts, the energy of sunlight is converted and stored in chloroplasts as ATP and NADPH which serve as energy-storage molecules. Their role in photosynthesis is their main role, but chloroplast are also involved in immune response, as well as in synthesis of fatty acids and some amino acids.