PROTEINS

Proteins are made by building long chains of amino acids.
The Amino acid structure looks like this:

• The R side chain is attached to central Carbon.
• Each R side chain has a different structure to it
• Twenty different types of side chains (20 amino acids)

• Amino acids are linked together to form long chains.
• Linked together by Peptide bonds a special covalent bond found in proteins.
• Proteins are sometimes called Polypeptides.
• After the chains of Amino acides are constructed, they can fold into more complex structures.

Four Levels of protein structure

• Primary - exact sequence of amino acids before folding.
• Secondary - simple folding create simple structures.
• Tertiary - folding results in complex 3D structures.

• Quaternary - multiple 3D subunits organized into a bigger structure.

Hemoglobin

• Carries oxygen in the blood- It's made up of 4 specific 3D subunits
• Proper protein function depends on correct 3D structure.
• Any change in the specific primary structure can cause the protein to fold differently.
• A different shape can lead to a different function (or lack of proper function).
• Sickle cell anemia is an example