Please help explain this better than I could Thanks If you h

Please help explain this better than I could. Thanks!

If you have two related (homologous) proteins, which do you expect to be the most similar, primary structure or tertiary structure? Why? Give a clear, coherent explanation.

Solution

Primary structure of protein consists of sequence of amino acids in a polypeptide chain.

The overall three-dimensional structure of a polypeptide forms the tertiary structure of protein. The protein molecule will bend and twist in such a way so as to achieve maximum stability. Stability is achieved by many stabilizing forces due to bonding interactions between the side-chain groups of the amino acids. Hydrogen bond, ionic bond, dipole-dipole interactions, etc contribute to the tertiary structure.

Out of two related (homologous) proteins, it is likely that tertiary structure tends to be most similar. This is because in case of primary structure of proteins, changing just one amino acid in a protein’s sequence can affect the protein’s overall structure. But the tertiary structure give rise to a three-dimensional structure of polypeptide, where hydrophobic regions cluster together on the inside of the protein, leaving hydrophilic amino acids on the outside to interact with surrounding water molecules.