Proteins contain the atoms; carbon, oxygen, hydrogen, nitrogen and sometimes sulfur
Two amino acids join to form a dipeptide
A chain or more than two amino acids is called a polypeptide
Monomers are amino acids
Plants can make their own amino acids
Animals can only make some amino acids. Some must come from the diet – essential amino acids
Proteins are made up of one or more polypeptide chains
The R-group is different in each amino acid
Amino acids contain an Amine group and Carboxyl group
Amino acids contain an Amine group and what other group?
Carboxyl
Primary Structure of a protein is the specific sequence of amino acids in a polypeptide chain
The secondary structure of a protein is the coiling or folding of the polypeptide chain due to the formation of hydrogen bonds
Two main 3D shapes formed in secondary structure are:
Alpha helix
Beta pleated sheet
Tertiary structure is the overall 3D shape of a protein molecule
There are four types of bonding involved:
1. Hydrogen bonds
2. Ionic bonds
3. Disulphide bonds
4. Hydrophobic and hydrophilic interactions
The quaternary structure of a protein is the way that two or more polypeptide subunits are arranged to give a final specific shape. E.g insulin and collagen
Quaternary structure
Refers to the arrangement of multiple polypeptide chains (or subunits) in a protein complex (e.g. insulin, collagen)
Secondary structure
Refers to the local spatial arrangement of the polypeptide backbone (e.g. alpha helix, beta sheet)