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Some foods are made from almost entirely the same food type, for example, the potato is nearly all starch, while other foods such as milk, are far more complicated. Our bodies have to break down food into simple substances that can be absorbed by a process called digestion.

Digestion and Enzymes

The process starts when food enters our mouth. Our teeth and jaws chew the food up into smaller pieces that can be swallowed. It is also mixed up with an enzyme called saliva that chemically reacts with the food and starts to digest it. The food then goes down the gullet into our stomach. Here other digestive juices are added and the muscles of the stomach mix it all together. It then travels into the small intestine where more juices are added and the fully digested food is absorbed into the blood which takes it to the cells around the body to give them energy. Food that cannot be digested continues into the large intestine where water is absorbed and eventually the waste and unwanted food passes out of our bodies.

Enzymes speed up the chemical reactions that aid digestion. They work most effectively at 37 degrees Celcius-human body temperature and are found at many places along the Alimentary Canal. Rennin is an enzyme that is found in our stomachs and is also present in a liquid called rennet. Enzymes work to break down starch, protein and fat. Enzymes are needed to chemically break down our food into smaller, soluble particles that can pass through the lining of our small intestine and enter into our blood supply. The particles of glucose are taken to the cells and used for respiration, giving us energy. Food that cannot be broken down is egested out of our bodies.

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