ATP is produced
in the chloroplast by Chemiosmosis.
Chemiosmosis
requires a phospholipid bilayer, a proton pump, protons and ATPase.
Chemical Energy
is used to pump protons through a proton pump (intrinsic protein).
This creates a high concentration of protons (H+) inside the thylakoid
disk.
ATPase has a channel
that allows for the facilitated diffusion of protons back in through the
membrane. This activates ATPase, which in turn catalyzes the formation
of ATP.
In summary, the chemical
energy is transferred to a proton pump which creates a proton gradient
across the membrane. This gradient is used to activate the enzyme
ATPase. ATPase catalyzes the formation of ATP