Fibrous and Globular Proteins

There are two major groups of proteins, fibrous and globular. Make sure you pay attention to their structural differences. These differences affect their properties and functions. Fibrous proteins end up having strand-like or sheet-like structures, and globular proteins coil and zigzag into complex and diverse structures.

Fibrous Globular Digital imagery © 1999 PhotoDisc, Inc. You will find fibrous proteins in hair, skin, and connective tissue, etc. They are flexible but strong proteins. They are made up of simple amino acid sequences with few R groups. The amino acid glycine (which has no R groups attached to it) is prevalent in fibrous proteins. Digital imagery © 1999 PhotoDisc, Inc. Globular proteins have more complex sequences of amino acids than fibrous proteins. This gives them a wide variety of shapes and functions. Of the nearly 2,000 different known enzymes, most are globular proteins. Some examples of globular proteins are antibodies, hemoglobin, and several hormones.