Proteins
• Monomer: amino acid
– Only twenty found in nature
– Each has an amino group (-NH2) and a
carboxyl group (-COOH)
– Monomers are joined together by peptide
bonds.
• Polymer: polypeptide
– A protein is made up of one or more
polypeptides.
How can there be
so many different
proteins when
there is only 20
amino acids?
Proteins
• Function:
– Controls the rate of a reaction
– Form bones and muscles
– Transport substances
– Fight disease
• A combination of ionic, covalent, hydrogen and Van
der Waals are responsible for 3D shape.
• Any change in the shape of a protein will make it
ineffective.
Levels of protein organization
Levels of protein organization
A protein’s shape depends on four levels of
structure
1. Primary Structure
Is the sequence of amino acids forming its
polypeptide chains
2. Secondary structure
Is the coiling or folding of the chain, stabilized
by hydrogen bonding
3. Tertiary Structure
Is the overall three dimensional shape of
a polypeptide
4. Quaternary Structure
Results from the association of two or more
polypeptide chains together-collagen