Autotrophic organisms make organic
compounds from Carbon Dioxide.
They rely on Photosynthesis.
Light Dependent Reaction
Aims: 1) Produce ATP.
2) Photolysis of Water
1. A photon of light
hits a chlorophyll
molecule. Energy is
transferred to the
2. Electrons excited: Raised to higher energy level
3.Leaves Chlorophyll molecule immediately
4. Picked up by an electron
carrier/acceptor. Through a series of
redox reactions and moving down
acceptors at different energy levels,
energy is then released to help form
5.NADP then picks up the electron, becoming reduced NADP
6. The Chlorophyll now needs to
be restocked of electrons, so
photolysis of water occurs.
4OH- - 4e- (lost to chlorophyll) ---> O2 + 2H2O
Occurs in Thylakoid
Light Independent Reaction
Occurs in the Stroma
Needed for life
Consisting of an Adenine base, ribose
sugar and triphosphate. Each bond
between the phosphates is broken to
release energy through a hydrolysis
reaction. This is catalysed by ATPase. ADP
is then formed and a free inorganic
phosphate. It is a reversible reaction.