k) l) m) Amino Acids & Protein Structure

Structure of Amino Acid

Dipeptide Formation Reaction

2 amino acids join together to form a dipeptide

A molecule of water is removed

- Ensure to circle the OH and H reacting, and label the peptide bond, and write in the H2O molecule removed

Primary structure

The sequence of amino acids bonded by peptide bonds

Secondary structure

Folding of the polypeptide chain.

Held in place with hydrogen bonds

Alpha helix or beta pleated sheets

Tertiary structure

Further folding of the polypeptide chain

Held in place with:

- Hydrogen bonds

- Disulphide bridges

- Ionic bonds

- Amino acids with hydrophobic R groups orientated to the centre of the protein, amino acids with hydrophilic R groups orientated towards the outside of the protein

Quaternary structure

More than 1 polypeptide chain