The major food molecule in living organisms is a sugar called glucose. Most carbohydrates (sugars and starches) are converted into glucose before they are broken down in the cytosol to release energy. ... If oxygen is present, then glucose can be broken all the way down into carbon dioxide and water.
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.
The nucleus of the cell directs cell activity and acts like the control center. This is the place where gene activity is controlled in terms of the replication of the genes. In addition the movement and actions of the cell are also dictated from the nucleus.
The majority of photosynthesis occurs in the chloroplasts.