The answer to this question should be: Calvin cycle
Calvin cycle is a chemical reaction that was done in the chloroplast of a plant. This is one of the reactions in photosynthesis. In Calvin cycle, carbon dioxide and water will be used to make carbohydrates(glucose). This reaction is forming energy using the sunlight so only autotrophic organism capable that will be able to do it.
The enzyme that is present within the stomach and the lining of the muscular gland, would function optimally in high H+ concentration and would require much HCl needed for an appropriate pH environment to function
This would be pepsin, I believe.
