1. Protein Structure
Proteins are polymers of amino acids linked by peptide bonds.
Each protein is made up of a unique sequence of amino acids of a particular chain length.
Most amino acids have the same general chemical formula.
The R represents the unique side chain that distinguishes one amino acid from another.

2. When two amino acids are joined together by a peptide bond, an amide structure results.
Further peptide bonding with more amino acids will result in a polypeptide (proteins are polypeptides).

3. Biological Functions of Proteins
Proteins are important for the structure and function of all living cells including:
Structural tissues such as skin and tendons;
Haemoglobin in blood and Myoglobin in muscles, which carry oxygen;
Muscles which provide the ability of movement;
Enzymes and hormones which help to regulate body processes;
Antibodies involved in immune function.

4. Proteins in Food
Provide the body with the essential building blocks it needs to function.
Providing the body with energy.
Consumption of protein containing foods is essential.
Foods vary in their protein content
Food processing can impact on a foods final protein concentration.