Photosynthesis is a process by which energy provided by sunlight is used to create a complicated molecule (glucose) from simpler molecules (CO2 and H2O). The reaction is

6CO2 + 6H2O ---> C6H12O6 + 6O2.

The entropy of the system decreases during this process, yet it is an endothermic reaction. How is this possible in view of the second law of thermodynamics?

1. One of the above assertions is false; the entropy of the system does not decrease during the reaction.

2. Although glucose is a more complicated molecule than CO2 and H2O, there is enough entropy in the O2 products to make the reaction generate entropy overall.

3. One of the above assertions is false; photosynthesis is an exothermic reaction, the heat from which increases the entropy of the surroundings.

4. The energy provided by the sun is not completely converted into chemical potential energy; the excess energy is dumped into the surroundings, increasing its entropy enough to pay for the entropy decrease associated with the reaction.

5. The second law does not apply in this case.