BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Other interactions between R groups of amino acids such as hydrogen bonds, ionic bonds, covalent bonds, and hydrophobic interactions also contribute to the tertiary structure. In some proteins, such as antibody molecules, several polypeptides may bond together to form a quaternary structure.

Detailed explanation-2: -Many proteins are formed from more than one polypeptide chain. The quaternary structure describes the way in which the different subunits are packed together to form the overall structure of the protein. For example, the human hemoglobin molecule shown below is made of four subunits.

Detailed explanation-3: -To help maintain their structures, the polypeptide chains in such proteins are often stabilized by covalent cross-linkages. These linkages can either tie two amino acids in the same protein together, or connect different polypeptide chains in a multisubunit protein.

Detailed explanation-4: -… protein; a molecule contains four polypeptide chains (a tetramer), each chain consisting of more than 140 amino acids. To each chain is attached a chemical structure known as a heme group.

Detailed explanation-5: -One or more polypeptide chains make up proteins. Each polypeptide chain is made up of smaller subunits or amino acids bonded together. Polypeptides are the building blocks of proteins, and amino acids are the building units of polypeptides.