Why do plants complete photosynthesis?

To perform photosynthesis, plants need three things: carbon dioxide, water, and sunlight. for photosynthesis. ... The energy from light causes a chemical reaction that breaks down the molecules of carbon dioxide and water and reorganizes them to make the sugar (glucose) and oxygen gas.

materials water oxygen those are the things i can think of in this moment.

image result for how many calories of energy will 20 grams of carbohydrates provide in one gram provides 4 calories

consuming the right balance of protein, carbohydrates and fat can you maintain a healthy weight and optimize your energy levels. protein and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.