Proteins
Proteins along with carbohydrates and fats are important macro nutrients.
On average protein provides the body with approximately 10-15 per cent of its daily calorific intake (approx 50g for women and 90g for men, depending on lifestyle). Proteins are used for building, maintenance and reparation of body tissue such as muscle. Proteins are large molecules which are made up of amino acid sub units.Amino acids can be classified into essential and non-essential amino acids. Essential amino acids have to be obtained through diet; these include valine, tryptophan, and isoleucine. Non-essential amino acids which include alanine, cysteine and glycine can be synthesised in the body.Amino acids join together with a peptide bond to form peptides. A peptide is a compound that consists of two or more amino acids, when there are 10 or fewer amino acids joined together the compound is known as an oligopeptide. Polypeptides are chains of 10 or more amino acids. Peptides containing more than 50 amino acids are classified as proteins.
Eggs, for instance, contain the whole range of amino acids and as such are a great source of protein
The diagram displays 2 amino acids joining together with a peptide bond, resulting in a dipeptide and a water molecule (H20)