Biolo1100
Chapter 6
Photosynthesis: Acquiring Energy from the Sun
Photosynthesis
takes place in the
leaves
of plants to transform light energy into the chemical energy of
carbohydrates
via
pigments
.
This process involves two steps: the light-
dependent
reactions
and the light-
independent
reactions (Calvin cycle).
Light-dependent reactions
Groups of pigments are embedded in
thylakoid
membranes
and organized into
photosystems
to capture light energy in
electrons
.
Two
electron
transport
systems
harvest the energy in the electrons to produce
ATP
and
NADPH
.
The
Calvin
cycle uses products of the light-dependent reactions,
ATP
and
NADPH
, to build carbohydrates from CO
2
.