Which row gives the correct description of the primary structure, secondary structure, tertiary structure and quaternary structure of certain proteins?
- APrimary structure determines the folding of the polypeptide; secondary structure depends on hydrogen bonding between the side-chains of amino acids; tertiary structure defines the overall shape and folding of the protein; quaternary structure formed when two or more identical polypeptides join together.
- BPrimary structure defines the order of amino acids in the polypeptide; secondary structure usually forms immediately after polypeptide synthesis; tertiary structure is held together by all the types of bonding that occur in proteins; quaternary structure found in globular proteins such as haemoglobin but never in fibrous proteins.
- CPrimary structure involves covalent bonds only; secondary structure involves interactions between $-\text{H}$ and $=\text{O}$; tertiary structure essential for the function of enzymes and receptors; quaternary structure formed when two or more polypeptides join together.
- DPrimary structure involves peptide bonds between the side-chains of amino acids; secondary structure involves folding between local regions within a polypeptide molecule; tertiary structure changes reversibly when bound to non-competitive inhibitors; quaternary structure can involve hydrogen bonds, covalent bonds and hydrophobic interactions.