Protein Quaternary Structure

Quaternary structures refers to the spatial arrangement of mulitple polypeptide chains to form ________ complexes

multisubunit

2 polypeptides

dimer

2 polypeptides with identical subunits

homodimer

2 polypeptides with different subunits

heterodimer

3 polypeptides

trimer

4 polypeptides

tetramer

Interface of the subunits are usually the

active site

What is the main force between individual protein subunits

hydrophobic effects

This force helps the alignment of the subunits and provides specificity

ionic interactions

What type of forces easily associate or dissociate which is good for regulation of protein function

Weak forces

Multisubunit complexes provide _______ that are not present in individual subunits

active sites

Why are multisubunit complexes more stable

lower delta G

Multisubunit complexes increase _____ and ______ by linking functional component in close proximity

functionality, efficiency

Multisubunit complexes provide a mechanism for ______ of protein function through conformational changes that alter the protein subunit interfaces

regulation