Chloroplast

An organelle associated with photosynthetic cells which are involved in production of organic molecules from NADPH and ADP; photosynthetic products. These organelles are found in plants and algae, and belong to the plastid family. Present in the membrane is a precursor to chlorophyll; light exposure converts the precursor to the green pigment, but remains yellow in dark conditions. It is thought that chloroplasts are similar to mitochondria with respect to their evolution; they have both endocytosed a species of bacteria and evolved symbiotically. Also, their ATP-synthesis mechanisms are very similar with mitochondria driven by respiration and chloroplasts driven by light .