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Chemical Elements

Biology: Edexcel IGCSE, topic 2.2.1

Chemical Elements

All molecules are made up of chemical elements. These are some of the most important molecules in living organisms, and the elements that they are made of.

Proteins

Proteins

  • Proteins are made up of the elements carbon (C), hydrogen (H), oxygen (O), nitrogen (N) and sulphur (S).
  • Proteins can give structural support, and many have important roles in chemical reactions in living organisms.
Carbohydrates

Carbohydrates

  • Carbohydrates are made of the elements carbon (C), hydrogen (H) and oxygen (O).
  • They can be useful for structural support, and also as a source of stored energy.
Lipids

Lipids

  • Lipids are made up of the elements carbon (C), hydrogen (H) and oxygen (O).
  • These are fats and oils. They make up cell membranes, and are also an important source of stored energy.

Test yourself on Chemical Elements

  • Which chemical element is not found in lipids?

  • Which chemical elements are found in carbohydrates, lipids and proteins?

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