Protein is a long chain-like molecule that is made up of small units known as amino acids, joined together by peptide bonds.
The word protein is derived from the Greek word 'proteios' which means "primary" or "in the lead".
Like carbohydrates and fats, proteins are considered a major nutrient for the body due to the energy (calories) they provide.
Protein is essential for life, it is crucial to all cells in the body playing a key role as enzymes in a cell. After water, protein is the most plentiful substance in the body.
Proteins grow, maintain, and replace the tissues in our bodies. Therefore our muscles, organs, and immune systems are mostly made of protein.
Once protein is digested it is broken down into its amino acids. These amino acids can then be reused to make the proteins your body needs to maintain muscles, bones, blood, and body organs.
There are over 20 slightly differing amino acids. Our bodies can produce around 13 of these, but there are 9 amino acids that our body cannot make itself. These are called essential amino acids and we obtain these by eating certain protein-rich foods.
Complete protein that has all amino acids including essential ones are meat, poultry, fish, dairy products, eggs, and soy. Incomplete protein sources include nuts, grains, fruits, and vegetables. Therefore it is important for vegetarians to pair meals wisely in order to get all essential amino acids in their daily diet.
Keratin is a type of protein that our hair, nails and outer skin is made off.
Taking on too much protein can be dangerous to the body, it is a strain on the liver and kidneys causing them to work extra hard to get rid of the extra protein.
Like the other energy sources, carbohydrates and fat, too much protein can also lead to weight gain.
The protein contained in eggs is considered to be the highest quality protein out of all foods.
Insects actually contain quite high levels of protein, more than some normal protein foods.
Proteins in some food can cause allergies as the structure of a protein can cause a reaction in the immune system. A lot of people are allergic to gluten for example, which is a protein in wheat and grains.