The primary structure dictates secondary and
Primary
tertiary structure
*linear chain of Amino Acids
Most important level to assess
Alpha Helix: a delicate coil held together by
Secondary
hydrogen bonds between every fourth amino
*Regions stabilized by hydrogen bonds b/w
acid
atoms of the polypeptide backbone
Beta Pleated Sheets: two or more segments
of the polypeptide chain lying side by side are
connected by hydrogen bonds
The overall shape of a polypeptide resulting
Tertiary
from interactions between the side chain of
*3D shape stabilized by interactions between
the various amino acids
side chains
“R” group interactions (ionic bonds,
hydrogen bonds, van der waals)
If it has a single polypeptide, it is finished
here and assumes a function
The overall protein structure that results
Quaternary
from the aggregation of polypeptide subunits
*Association of two or more polypeptides
(some proteins only)
Example: hemoglobin
Protein that consists of more than 1
polypeptide (multiple subunits)
Primary
tertiary structure
*linear chain of Amino Acids
Most important level to assess
Alpha Helix: a delicate coil held together by
Secondary
hydrogen bonds between every fourth amino
*Regions stabilized by hydrogen bonds b/w
acid
atoms of the polypeptide backbone
Beta Pleated Sheets: two or more segments
of the polypeptide chain lying side by side are
connected by hydrogen bonds
The overall shape of a polypeptide resulting
Tertiary
from interactions between the side chain of
*3D shape stabilized by interactions between
the various amino acids
side chains
“R” group interactions (ionic bonds,
hydrogen bonds, van der waals)
If it has a single polypeptide, it is finished
here and assumes a function
The overall protein structure that results
Quaternary
from the aggregation of polypeptide subunits
*Association of two or more polypeptides
(some proteins only)
Example: hemoglobin
Protein that consists of more than 1
polypeptide (multiple subunits)
