Biological molecules

• A biological molecule is any molecue that is produced by a living organism. They include:

  • Carbohydrates
  • Proteins
  • Lipids
• These molecules are made up mainly of carbon, hydrogen, oxygen and nitrogen.
• Carbohydrates provide us with the fuel that makes all the other reactions of life possible.
• Carbohydrates contain the chemical elements carbon, hydrogen and oxygen.
• All carbohydrates are made up of units of sugars.
• Some carbohydrates contain only one sugar unit, for example glucose, C6H12O6. Other carbohydrates are made up of two sugar units joined together, for example sucrose.
• Complex carbohydrates such as starch and cellulose are made up of long chains of simple sugar units bonded together.
• Proteins are made up of long chains of amino acids. There are over 20 different amino acids. The amino acids can be arranged in any order, resulting in hundreds of thousands of different proteins.
• Proteins contain carbon, hydrogen, oxygen and nitrogen.
• Protein rich foods include meat, fish, pulses, eggs, dairy products, and legumes.
• The long chains of amino acids that make up a protein are folded and coiled to make specific 3D shapes. The bonds that hold the proteins in these 3D shapes are very sensitive to temperature and pH, and can easiy be broken. If this happens, the shape of the protein is lost and it may not function anymore. The protein is denatured.
• Proteins carry out many different functions in your body. They act as:

  • structural components of tissues such as muscles and tendons hormones such as insulin antibodies, which destroy pathogens and are part of the immune system.
  • enzymes, which act as catalysts.
• Lipids (fats and oils) are made up of fatty acids and glycerol - most lipids in the body are made up of triglycerides (1x glycerol, 3x fatty acids)
• Lipids contain carbon, hydrogen and oxygen
• Lipids are the most efficient energy store in your body and an important source of energy in your diet, they're very important in your cell membranes, as hormones, and in your nervous system.
• All lipids are insoluble in water
• Lipid rich foods includes all the oils, such as olive oil and corn oil, as well as butter, margarine, cheese and cream