The process of what happens to the carbon atoms during
photosynthesis is known as the Calvin Cycle. The first step in the Calvin cycle
is the carbon fixation stage. This stage begins when the carbon dioxide
molecule is attached to a ribulose biphosphate, also known as RuBP. The ribulose
biphosphate is a five carbon sugar that is made into an unstable 6 carbon
compound that splits into two molecules that are 3-phosphoglycerate. The next
step is the endergonic reduction process. Which begins is a two-step process
that begins with coupling the ATP hydrolysis with the reduction of the 3-phosphoglycerate
and produces glyceraldehyde phosphate. The NADPH reduces the carboxyl group
from electrons of one 3-bisphosphoglycerate to glyceraldehyde-3-phosphate of the
aldehype group. There are six glyceraldehyde-3-phosphate for every three carbon
dioxide molecule that are used in the process of the Calvin cycle but only one
can be counted as a gain the other five regenerate three molecules of RuBP that
is part of the final step. The final step in the process is the regenerations
of the RuBP that is a series of reactions that rearranges the carbon skeleton
of the five glyceraldehyde-3-phosphate into the three molecules of RuBP that requires
the three ATP molecules. Once the reaction is complete, it begins the Calvin
Cycle all over again. Once the Calvin cycle is started again the entire process
is repeated from the start with the new molecules. The process continues in a
never ending loop that follows the same three steps over and over again.
