Here is another in our series of blogs on the biology of food. This blog looks at the major food groups found in a curry. This blog will be useful for those studying IGCSE Biology, Human Biology or Science, and GCSE Biology or Science.
Curry (digestion) comes under the following specification sections: Edexcel IGCSE Biology, 2e, and AQA GCSE Biology, 12.6.
Meat, veg, spices and rice – the ingredients of a tasty curry, and also examples of the major food groups needed to keep our bodies functioning. Proteins, fats and complex (starchy) carbohydrates form the majority of the food we eat, but the molecules they are made from cannot be absorbed by the body because they are large and insoluble. The process of digestion describes the action of special molecules called enzymes which can break down large, insoluble molecules to produce small, soluble ones. These small molecules can pass into the body through the small intestine and be transported by the blood to wherever they are needed.
Carbohydrates – mainly in the rice.
Digestion of starchy carbohydrates starts in the mouth with the action of the enzyme amylase. It breaks down long starch molecules into shorter sugar molecules called maltose. The digestion continues in the small intestine with the enzyme maltase breaking down maltose to form glucose. Glucose can be absorbed into the blood through the walls of the small intestine.
Fats – in the meat and cooking oil.
Bile, which is produced by the liver, is stored in the gall bladder and released into the small intestine. It emulsifies fats (turns them into tiny droplets). The enzymes which digest fats are called lipases. These break down fats and oils into fatty acids and glycerol in the small intestine, where they can be absorbed into the blood.
Proteins – mainly in the meat, some in the rice.
Proteins are digested by protease enzymes into amino acids. The enzymes are produced in the stomach, pancreas and small intestine. Amino acids are soluble and can be absorbed into the blood in the small intestine.
Vitamins and minerals – in the spices.
Last but not least, the spices provide the delicious flavours as well as some trace minerals and vitamins.