The arrangement of multiple polypeptide subunits into one functional protein, such as haemoglobin.
Haemoglobin has four subunits (two alpha, two beta), each with a haem, which allows cooperativity. Collagen is a triple helix and antibodies have four chains. Subunits are held by the same non-covalent bonds as tertiary structure.
Not all proteins have quaternary structure; it requires more than one polypeptide.
The arrangement of multiple polypeptide subunits into one functional protein, such as haemoglobin.
Quaternary Structure is one of the 51 topics in Biomolecules & Biochemistry. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Tertiary Structure, Cooperativity, Proteins.
Subunit interaction lets regulation occur, for example one oxygen binding makes the next easier.
Work through the Beginner topics in Biomolecules & Biochemistry first, such as Water Properties, Carbon Chemistry, Carbohydrates, then return to Quaternary Structure. Intermediate topics assume the Beginner vocabulary.
The closest topics to Quaternary Structure are Tertiary Structure, Cooperativity, Proteins, Carbon Chemistry. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Quaternary Structure. To practise the whole of Biomolecules & Biochemistry, use the Biomolecules & Biochemistry quiz.
Quaternary Structure: The arrangement of multiple polypeptide subunits into one functional protein, such as haemoglobin. Tertiary Structure: The overall three-dimensional shape of one polypeptide, held by side-chain interactions and disulfide bridges. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Tertiary Structure and explain the difference aloud. Finally, take the Biomolecules & Biochemistry quiz and come back to this page for any question you miss.
The overall three-dimensional shape of one polypeptide, held by side-chain interactions and disulfide bridges.
⚗️ Biomolecules & BiochemistryBinding of a ligand to one subunit alters affinity at others, giving haemoglobin its sigmoidal oxygen curve.
⚗️ Biomolecules & BiochemistryPolymers of amino acids that act as enzymes, structural parts, transporters, hormones and antibodies.
⚗️ Biomolecules & BiochemistryCarbon forms four covalent bonds, allowing chains, rings and the huge variety of organic molecules in living things.
⚗️ Biomolecules & Biochemistry