Ответьте на вопросы по тексту
1.What does the body require for life?
2.Can food be utilized in the form in which it is eaten?
3.How is the processing of the food by the body called?
4.What are enzymes?
5.What does our food consist of?
6.Where are proteins found?
7.What are proteins necessary for?
8.What do carbohydrates provide body cells with?
9.Where is body fat stored?
10.How does body fat act?
11.How much water is it necessary to drink daily?
Digestion
For life to continue, the body requires fuel in the form of oxygen and food.
Respiration provides the oxygen. Our food, however, cannot be utilized by the body in the form in which it is eaten. It must be specially processed by the body before it can be of any use. This special processing is known as digestion. It is brought about by the action on the food of certain substances called enzymes which are made by the body and mixed with the food during its passage through the body.
The food we eat consists of protein, carbohydrate and fat. It also contains small quantities of vitamins and minerals.
Proteins are found in meat, fish, eggs, milk and cheese. They are broken down into amino – acids during digestion. Protein is necessary for cell growth and repair.
Carbohydrates are found in sweet and starchy foods such as sugar, flour and potatoes.
They are broken down into glucose during digestion. Carbohydrates provide body cells with the energy required to perform their functions.
Fats are found in meat, fish, dairy products and vegetable oils. The digestive process breaks them down to fatty acids. Fats provide energy and body fat, which is stored in a layer beneath the skin. It acts as a reserve source of energy when needed, and also as insulation which helps maintain body temperature in cold weather.
The body required water for the production of blood, digestive juices, urine and sweat. Many foods contain a large quantity of water but it is still necessary to drink more than a liter of fluid daily.