Practice Questions

1.Define the term digestion

Digestion is the process of breaking down large insoluble food molecules into smaller soluble ones. 

2.Which organ produces bile?

Liver

3.Name the organ that connects the mouth to the stomach.

Oesophagus

4.Explain how different organs of the digestive system work together to break down food and absorb the products of digestion. In your answer, refer to enzymes and physical adaptations.

Food is chewed in the mouth and mixed with saliva, which contains amylase to start digesting starch.

The stomach produces hydrochloric acid to kill bacteria and provides the optimum pH for protease enzymes, which break down proteins into amino acids. The liver produces bile, stored in the gallbladder, which neutralises stomach acid and emulsifies fats to increase the surface area for lipase.

The pancreas produces enzymes (amylase, protease, lipase) that act in the small intestine.

The small intestine has villi and microvilli, giving a large surface area, and a good blood supply to absorb glucose, amino acids, fatty acids and glycerol.

The large intestine absorbs water from undigested food, forming faeces.