globular proteins

Comparison of globular and fibrous proteins.
Structural comparison of globular and fibrous proteins.

Globular proteins are proteins that consist of long chains of amino acids folded up into complex shapes. Globular proteins serve as, or form important components of, the following:


· Enzymes
· Hormones
· Antibodies


Some globular proteins have a structural role. For example, globular proteins form part of the cell membrane, which has a structural role as well as a role in transporting ions in and out the cell.


The structure of globular proteins has been traditionally discussed in terms of four levels of structure: primary, secondary, tertiary, and quaternary. Two additional levels are now commonly distinguished: motifs and domains.


The other main type of protein, in terms of its structure, is fibrous protein.