But we have not made any food for the plant. The Calvin cycle does not depend upon light and can occur in either light or dark conditions, unlike photophosphorylation. Remember that carbon dioxide is very low in energy and glucose is very high in stored energy. I have constructed a simplified series of animations of the Calvin cycle to show you how it works. Only the carbon atoms are shown and I have not identified any of the intermediate reactions involved.
Carbon fixation is much more complicated than what is shown here.
Nevertheless the most important results of the cycle are illustrated. A carbon atom from carbon dioxide enters the cycle and joins with a five carbon molecule that is present. 2 .The six carbon molecule that results, breaks up into two molecules, each with three carbon atoms. The energy that was released is used to raise the energy of the molecules reacting in the cycle. The bonds connecting this carbon atom to hydrogen and carbon are much higher in energy than the original C-O bonds of carbon dioxide.