INGLES I

TP.3

READING AND COMPREHENSION

Sources of Energy

The fuels of the body are carbohydrates, fats and proteins. These are taken in the diet. They are found mainly in cereal grains, vegetable oils, meat, fish, and dairy products.

Carbohydrates are the principal source of energy in most diets. They are absorbed into the bloodstream in the form of glucose. Glucose not needed for immediate use is converted into glycogen and stored in the liver. When the blood sugar concentration goes down, the liver reconverts some of its stored glycogen into glucose.

Fats make up the second largest source of energy in most diets. They are stored in adipose tissue and round the principal internal organs. If excess carbohydrate is taken in, this can be converted into fat and stored. The stored fat is utilized when the liver is empty of glycogen.

Proteins are essential for the growth and rebuilding of tissue, but they cal also be utilized as a source of energy. In some diets, they form the main source of energy. Proteins are first broken down into amino acids. Then they are absorbed into the blood and pass round the body. Amino acids not used by the body are eventually excreted in the urine in the form of urea. Proteins, unlike carbohydrates and fats, cannot be stored for future use.

  • Decide if the following sentences are true or false according the information in the text above. If they are false justify them (in Spanish).
  1. The fuels of the body are taken in the diet.
  2. Carbohydrates, fat and proteins are found only in cereal grains, vegetable oils, meat, fish and dairy products.
  3. Carbohydrates are stored in the liver as glycogen.
  4. Fats are stored only round the principal internal organs.
  5. Proteins are essential for growth and energy.
  6. Proteins are the main source of energy in most diets.
  7. Amino acids which are not absorbed into the blood are excreted in the urine in the form of urea.
  8. Carbohydrates and fats cannot be stored for future use.
  • Rewrite the following sentences replacing the underlined words, with expressions from the text, which have the same meaning.
  1. Cereal grains are one of the main sources of carbohydrate in the diet.
  2. Glucose, which is not needed immediately, is converted into glycogen.
  3. Carbohydrates are stored in the liver as glycogen.
  4. The liver reconverts some of its glycogen when the blood sugar concentration falls.
  5. If too much sugar is ingested, it is excreted in the urine.
  6. A well-balanced diet is necessary for growth and energy.
  7. In contrast with milk, beef contains no vitamin A and no vitamin C.
  8. Glycogen, derived from glucose, is stored for later use.