Science & Technology in Action

1st Edition

The Importance of Nutrition


This lesson deals with the topic of human nutrition. It examines the body’s need for protein, carbohydrates, minerals and vitamins and stresses the importance of fish as a source of valuable nutrients.
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Lesson excerpt

What is a nutrient?
In this lesson we will look at the importance of nutrition and the role each of the main biomolecules - proteins, carbohydrates, lipids (fats, oils) and vitamins as well as the role of minerals in providing a balanced diet to supply our body with sufficient nutrients.

A nutrient is any substance absorbed by an organism from its external environment and used in the organism's metabolism. Nutrients are both a source of energy and a source of materials needed for growth, maintenance, defence and reproduction of cells.

What is food?
Food is a nutrient-rich material. As such, it is a good source of one or more of the following - proteins, carbohydrates and lipids. In addition, our diet must also contain foods which supply vitamins, minerals and water. The process by which an organism obtains energy and materials needed for its metabolism is called nutrition.

What is metabolism?
Metabolism is all the biochemical reactions, both anabolic and catabolic, that take place in the life of an organism. Anabolism is the formation of large complex organic molecules by the linking smaller simpler biomolecules. Anabolic reactions require energy to take place.Catabolism is the breakdown of these large complex biomolecules into smaller simpler biomolecules. Catabolic reactions release energy as they occur.

True or False?

  1. Nutrients are imported from our external environment. true
  2. All nutrients are a source of energy. false
  3. All the chemical reactions occurring in an organism is called metabolism. true
  4. Anabolism involves the release of energy. false
  5. Our type of nutrition is autotrophism, i.e. we are producers. false
  6. Water is the nutrient needed in greatest quantity. false
  7. We cannot store excess protein in our body. true
  8. Meat and fish are not a good source of protein. false
  9. Lipid is soluble in water. false
  10. Most of the energy stored in our body is in the form of carbohydrate. false
  11. Lipid has relatively higher hydrogen content than carbohydrate. true
  12. Cell membranes are mostly composed of protein and carbohydrate. false