What is the purpose of photosynthesis in plants

The purpose of photosynthesis is to manufacture organic foods such as glucose from inorganic substances such as carbon dioxide and water, so that the glucose is broken down in the presence of oxygen during respiration to produce energy.

Explanation: Photosynthesis is a process by which green plants manufacture their own food using sunlight, carbon dioxide and water. The organic food produced by plants are used by both plants and animals to generate needed for cellular functions. During photosynthesis, plants use chlorophyll to trap sunlight and the energy from the sun is used to drive the synthesis of glucose in the presence of carbon dioxide and water. The glucose produced is broken down in the presence of oxygen during respiration to produce energy needed by plants for other cellular functions.

where in your body is there an enzyme that does function at a high or low ph? what is the name of that enzyme and its function?