Describe how the action of the mouth, oesophagus and stomach contributes towards the digestion of food? (6 Marks)

As this question is worth 6 marks, 6 different points need to be made to get all the marks. These could be two from each structure that is given. The teeth in the mouth break down food into smaller pieces (1) to reduce their surface area (2). It is also mixed with saliva so that it can be swallowed more easily (3) and is mixed with the enzyme amylase that starts breaking carbohydrates down (4). When the food is swallowed it enters the oesophagus. This pushes the food down towards the stomach(5) using peristaltic contractions of the muscles (6). The food then reaches the stomach. The muscles of the stomach contract and mix food with hydrochloric acid and digestive juices which help break down the food(6). There are enzymes in the stomach. One of these enzymes is pepsin, which breaks down proteins (7).