The key difference between homodimer and heterodimer is that homodimer is a protein made from two identical proteins, while heterodimer is a protein made from two different proteins.
Protein is a biomolecule composed of amino acid chains. A protein dimer is a quaternary protein structure formed from the union of two protein monomers or two amino acid chains. Generally, they bind with each other by non-covalent bonds. Protein dimers are either homodimers or heterodimers. A homodimer has two identical proteins which are non-covalently bound. Heterodimer has two different proteins bound together. This protein dimer interaction is important in regulation and catalysis.
