You didn't provide the reaction, but enzymes usually just help the reaction take place, often faster then it would in regular conditions. They are completely used up during the reaction and don't affect it in any other way, meaning they don't change the properties of the compounds.
Yes, there is growing evidence that cognitive impairment is associated with cigarette smoking.
The answer is ATP molecules being produced, this happens in light and dark.
All of the other options are either directly related to light/photosynthesis or are needed to complete it.
