Bio1151b
Chapter
10
Photosynthesis
Plants and
other
are the
of ecosystems and can convert
solar
energy
into the
energy in food by a process called
.
Heterotrophs are
(including decomposers), in the ecosystem, and obtain their energy from
other
organisms.
Photosynthesis
is a
process where water is
and carbon dioxide is
to
.
In plants, photosynthesis occurs in
organelles
called
,
which
contain its own ribosomes and
.
There are two
major
stages:
the light reactions and the Calvin cycle (light-independent reactions).
The light reactions occur in the
, where
pigment
molecules located in a
photosystem
absorb light and their electrons reach an
state.
Each excited
electron
is passed through an
transport chain
(ETC)
and another photosystem, where the energy is used to produce
and
reduce
NADP
+
to
.
The
Calvin
cycle occurs in the
to synthesize
from carbon
dioxide.
C4
plants are adapted to hot, dry climates by incorporating CO
2
into
-carbon as the substrate in the
Calvin
cycle.
The production of
carbon compounds from
CO
2
is called
fixation.