Water

The nutrients in food are needed to:

• provide energy
• supply raw materials to make new protoplasm
• help us stay healthy

In animals, water:

• is the solvent in which chemical reactions take place in living things
• is an essential component of cells, tissue fluids, digestive juices and blood
• helps control body temperature. When water from sweat evaporates from the skin surface, latent heat of vaporisation is removed and the body cools down.
• helps to transport dissolved substances around the body like digested products from the small intestine to other parts of the body and waste products from the cells for removal from the body

In plants, water:

• is essential for photosynthesis
• helps keep plant cells turgid and plant upright
• is needed for the transport of mineral salts up the xylem
• is needed for the transport of food substances from the leaves to other parts of the plant through the phloem