The food is produced in the leaves of the plants through the process of photosynthesis and from leaves it is then transported to various parts of the body through phloem tissues. The phloem requires energy in the form of ATP for the transportation of food materials. This results in the development of osmotic pressure inside the tissue that increases the movement of water into the tissues. The osmotic pressure results in the movement of the material in the phloem to those tissues which have less pressure. This helps the tissue in moving the food materials according to the needs of the plant. Sucrose is a food material that requires energy in the form of ATP when it is transported into the phloem tissue.