8.3 Summary/Concept Check

Summary:

The Calvin Cycle is the sugar making area of the chloroplast, the Calvin Cycle is just like the Krebs Cycle because the ingredients are always recycled for the next batch. The starting material in the Calvin Cycle is RuBP, a sugar with five carbon atoms. The Calvin Cycle starts with the RuBP and three CO2 molecules are combined with it to form three unstable six carbon molecules. They immediately splits into six 3 carbon molecules called 3-PGA. Later six ATP and six NADPH (from the light reactions) combine and turn 3-PGA into G3P. One G3P molecule exits the cycle to form glucose and other products. The rest of the G3P's are turned back to RuBP with the power ATP and sent back into the cycle and the ADP's and NADP+'s are sent back to the light reactions. The overall equation for Photosynthesis is "6 CO2+6 H2O --> C16H12O6+6 O2".

Concept Check:

1. The inputs and outputs of the Calvin Cycle include ATP, NADPH & CO2 and the outputs of the Calvin Cycle are ADP, NADP+ and Sugars (in the form of Starch, Fatty acids and Cellulose).



2. The ligh reaction stages uses the H2O reactant and the Calvin Cycle uses the CO2 as its reactant. But the product of the Light Reactions is O2 and for the Calvin Cycle is sugar or C6H12O6.



3. The Calvin Cycle is called a cycle because that stage regenerates the same molecules so that the cycle can go on so for instance the Calvin Cycle keeps on regenerating the RuBP molecule.



4. The sugar molecule is the direct product of photosynthesis and that molecule is then used to do construction in the plant cells and the plant itself.

Pictures:

Photosythesis Cycle:

Calvin Cycle: