3.2.1.1 Protein GapFill

Proteins are organic macromolecules built from  peptidesamino acidsadipose tissuecouscous, bound together into long chains.There are about 20 different amino acids which can combine to make a molecule of protein. Some of the amino acids can be built by the body from scratch – for this reason they are called 'dispensable'. If an amino acid cannot be built by the body from scratch, it is called  an essentiala high biological valuean insolublea miso amino acid and has to be provided as a part of a healthy diet.

There are  twoelevenninetwenty essential amino acids and if they are all present in a molecule of protein, such protein is called a complete protein and has a  incomplete valueinsufficient valuehigh biological valuehigh energy value. If one or more of the amino acids is missing, the protein is considered  a solida stablea low biological valuean unstable protein.

Protein  complementationcomplementingcorrelationcoagulation allows us to combine two or more sources of low biological value proteins to make a   fattytextured vegetableadequatewhole protein. An example of this is  hot dogcheese on toastbeans on toastspaghetti bolognese. Complete proteins occur mostly in  plant foodsfruits and vegetablesanimal-derived foodsnuts, but also in  breadgherkinscouscousquinoa and  soyolive oilgreen peastomatoes.

Proteins are necessary to build  lardunsaturated fatall cells in the bodyadipose tissue , enzymes and hormones. They can also be used as a  secondaryprimaryfreeinsoluble source of energy – this means that they are only used as a source of energy if other sources (carbohydrates and fats) are not available.
If a person eats too little protein, he or she may develop a disease called  scurvykidney stonesnight blindnesskwashiorkor. Too much protein can also be harmful for the body, causing harm to the liver and the kidneys.