Strike the Balance In diet 3

What exactly is protein?

Think of protein as strings of sausages. Long strings – some many thousands.  Each sausage represents one of 15 similar small molecules called amino acids. The order of amino acids in the chain is programmed by DNA.  “Amino” means that they contain nitrogen, but they also contain carbon, hydrogen and oxygen atoms.  In order to do their jobs, proteins curl up into characteristic shapes, and many of them need to incorporate minerals or vitamins in order to function.

Some proteins are solid, some are flexible in cell membranes, others are mobile in solutions. 

when we eat proteinous food;

The cells in your intestine can’t absorb whole proteins, only single amino acids or very small chains of two or three amino acids – called peptides.  So digestive enzymes (specialised proteins themselves!) break down the proteins into their component amino acids – essentially, cutting the string between the sausages.

The amino acids and peptides are absorbed into the bloodstream and safely delivered at different parts around your body where they are required, either to make new proteins or to be used to release energy.  Most arrive first at the liver, where most new protein are made, and where excess protein is broken down ready for burning as a fuel for metabolism.

In fact there are around 30,000 to 50,000 different proteins in the human body!  Each has its own unique gene in our DNA which arranges the 22 amino acids in a unique sequences.  Proteins in the body cells are continuously being formed and broken down by enzymes, so amino acids are continuously being recycled from broken down proteins as well as the diet.

The essential amino acids

Nine “essential amino acids” must be originally be supplied by your diet,  because your body does not have the ability to make (synthesize) them.

Those amino acids are ;

histidine

isoleucine

leucine

lysine

methionine

phenylalanine

threonine

tryptophan

valine

Our requirements for essential amino acids vary, depending on factors such as stage in life for growth and development, injury or illness.

Protein-rich foods are often rated in terms of how “complete” their amino acid profile is, in relation to needs for essential amino acids. Therefore, food that we get from animals and animal products (meat, fish, eggs, dairy) usually score highly on their amino acid profile and are subsequently regarded as “high-quality proteins”. Although we can support with other minor food that contains protein for variety taste and balance.