Globular and fibrous proteins

In globular proteins the polypeptide chain is folded into a compact spherical shape.
Fibrous proteins do not fold up into a ball shape but remain as longs chains.
The globular proteins are soluble due to the hydrophilic side chains that project from the out side of the molecules and are therefore important in metabolic reactions.
The fibrous proteins are insoluble (hydrophobic) and important structural molecules. Several polypeptide chains can be cross-linked for additional strength.
Haemoglobin is a globular protein. it acts as an oxygen transport molecule. It is made up of four polypeptide chains, each is associated with an iron-containing haem group (grey). Oxygen attaches to the iron with the haem group. Because the protein is associated with another chemical group it is called a conjugated protein.
Collagen is a fibrous protein. Three polypeptide chains wind around each other to form a rope-like strand held together by hydrogen bonds between the chains. Each strand cross-links to other strands to produce a molecule with tremendous strength.
They are all polypeptides
Both encoded by DNA
identical length
Varied length
Structural role
Functional and structural role

Resource summary

	Created by Mia Ward over 8 years ago