 Skip Navigation  2.11: Light Reactions of Photosynthesis   Are
plants the only organisms that perform photosynthesis?  Although
we generally discuss plants when learning about photosynthesis,
keep in mind that plants are not the only organisms that can
make their own food. Some bacteria and some protists, such as
the algae pictured here, also perform photosynthesis. This alga
has chloroplasts and photosynthesizes just like a plant.  The
Process of Photosynthesis  In the Presence of Sunlight, Carbon
Dioxide + Water → Glucose + Oxygen  Photosynthesis takes place
in the organelle of the plant cell known as the chloroplasts.
Chloroplasts are one of the main differences between plant and
animal cells. Animal cells do not have chloroplasts, so they
cannot photosynthesize. Photosynthesis occurs in two stages.
During the first stage, the energy from sunlight is absorbed by
the chloroplast. Water is used, and oxygen is produced during
this part of the process. During the second stage, carbon
dioxide is used, and gluc