ROUGHAGE
- When we eat vegetables and other plant materials, we are actually taking in a large quantity of plant cells (Remember the cell walls? They are made of inert carbohydrate called CELLULOSE)
- Humans cannot digest plant materials because humans cannot produce CELLULASE, an enzyme which can digest cellulose. Because of this, the plant cell walls reach the large intestine without being digested. This undigested part of the diet is called fibre or roughage.
- SO, WHAT THEN IS THE ROLE OF ROUGHAGE IN YOU DIET? The fibre add bulk to the contents of the colon and help it to retain water. This softens the faeces and reduces the time needed for the undigested materials to pass out of the body. This helps to prevent CONSTIPATION and keeps the colon in a healthy condition.
- Good sources of dietary fibres: wholemeal bread and bran.
WATER
- About 70% of most tissue consists of water and it is an essential part of cytoplasm.
- The body fluids, blood, lymph and tissue fluid are composed mainly of water.
- Water acts as a solvent and as a transport medium for digested food, salts and vitamins, and excretory products such as excess salt and urea respectively.
- Digestion is a process which uses water in a chemical reaction to break down insoluble substances to soluble ones.
- Loss of water from the body: SWEATING, URINATION and BREATHING OUT.
