When two protein chains combine to form an active protein, the structural level is the quaternary arrangement.
<h3>What do you mean by Proteins?</h3>
Proteins may be defined as naturally emerging, extremely intricate substances that comprise amino acid residues joined by peptide bonds.
The Quaternary structure of a protein is very complex and 3-dimensional as compared to other protein structures which involve numerous motifs and domains.
Therefore, when two protein chains combine to form an active protein, the structural level is the quaternary arrangement.
To learn more about Protein structures, refer to the link:
brainly.com/question/14207491
#SPJ4