Plants absorb water through their roots, and carbon dioxide through their leaves. Some glucose is used for respiration, while some is converted into insoluble for storage. The stored starch can later be turned back into glucose and used in respiration. Oxygen is released as a by-product of photosynthesis.
Green plants absorb light energy using chlorophyll in their leaves. They use it to react carbon dioxide with water to make a sugar called glucose. The glucose is used in respiration, or converted into starch and stored. Oxygen is produced as a by-product.
The key principal in this lab is for students to realize that starch is an important by-product of photosynthesis, and is used through the life cycle of plants. When foods are stored, they are usually in the form of nonsoluble materials. Before such foods can be utilized, they must first be converted to a soluble form. For example, when a seed is planted and watered, the first thing that happens (after water is absorbed and swells the seed) is the digestion of starch, fats, and proteins. The resulting sugars, fatty acids, glycerol and amino acids are then available and are utilized in the subsequent production of new cells, which develop into roots, stems and leaves. Once the leaves have formed the plant no longer is dependent upon the foods stored in the seed. Photosynthesis can now take place and foods are produced.
Photosynthesis, the most important reaction on Earth, is the basis of life on the planet. An understanding of it, and its counterpart, respiration, is the key to understanding life and atmospheric balance. Photosynthesis is the process in which plants make food. They need carbon dioxide,water, and energy from the sun.