The cycle of chemical reaction
s during photosynthesis
Named after its principal discoverer, Melvin Calvin
The cycle works like this:
ribulose bisphosphate ->
3-phosphoroglycic acid (PGA) ->
1,3-bisphosphoroglycic acid (DPGA) ->
3-phosphoroglyceraldehyde (PGAL) ->
fructose, glucose, and
ribulose phosphate ->
ribulose bisphosphate, which is now ready to take on some more CO2.
Source: John W. Kimball's Biology Pages, which note that
"All the reactions of carbon fixation occur in the stroma of the chloroplast".
This cycle is also known as light independent,
non-light requiring, or dark reactions, since the energy is provided by
ATP or NADPH molecules which are created by the light reactions.
"Thus the Calvin cycle is inseparable from the light reactions...they only
occur in the light! This is why "dark reactions" is a poor name for the Calvin cycle",
(L. Taiz and E. Zeiger, Plant Physiology, 2nd ed., 1998)
Melvin Calvin and Andrew Benson worked this out by studying
the green algae Chlorella at UCB.