Proteins are the building blocks of life, of which we and other living things are made. The word protein is derived from the Greek word protos, meaning ‘first’, indicates its importance.

Proteins are large and complex molecules, formed from chains of dozens to thousands of amino acids. All our proteins are made from just twenty amino acids which produce all types of proteins. These proteins are found in human body and all other living things, including plants.

Amino acids are made of carbon, hydrogen, oxygen and nitrogen. During digestion, the proteins break down into their components amino acids, which are then transported in bloodstream to wherever they are needed for growth, repair, maintenance or manufacture and any surplus to requirements needs to be broken down, as the nitrogen part cannot be stored and must be removed. This gives extra work for the liver, kidneys and heart. The remaining part of the amino acid is used either as fuel or converted to fat and stored for later use. When burnt as fuel in the body, one gram of protein produces four calories of energy.

Our bodies contain thousands of different proteins, each with its own individual structure and function. Every cell in our body is built with protein and needs protein for its functions. Proteins are the main components of our muscles, our internal organs, our skin which includes our nails and hair. Our bones too are formed in a protein matrix, as well as these structural tissues, proteins have vital roles as hormones and enzymes, enabling our complex biological processes to work, and also as antibodies, combating invaders like bacteria and viruses.

Enzymes: These are protein molecules that enable specific complex chemical changes to take place quickly and easily in the body. Many are involved in the digestion of food, breaking large molecules down to small components that can be absorbed and transported to where they are needed.

Hormones: They act as chemical messengers, travelling throughout the body and controlling the different metabolic activities.

The digestive enzymes that deal with food protein molecules are themselves molecules. They act like minuscule scissors, snipping up the food protein molecules into their component amino acids, ready to be absorbed into the blood and carried to where they are needed. There more enzymes enable them to work on growth, repair or manufacture.

The hormone insulin is one of the simplest proteins, containing only forty-eight amino acids. It controls blood sugar levels by acting as a key to unlock the sugar receptor points in the cell walls and letting the sugar in. without insulin, the sugar does not get into the cells and thus builds up dangerously high levels in the blood – and diabetes develops.