All proteins have primary (1°), secondary (2°) and tertiary (3°) structure. In addition, some (but not all) proteins exhibit quaternary (4°) structure. Explain quaternary structure and why only some proteins exhibit that level of structure.

The quaternary structure is the highest level of architecture common to all biologically active proteins.

Which covalent bond(s) is/are important for the formation of quaternary structure in proteins? (Please answer carefully ).

Tertiary structures refer to the three-dimensional arrangement of every atom in the molecule. On the other hand, primary structures refer to the stable arrangements of amino acid residues in a protein that give rise to recurring patterns. O Both statements are correct O Both statements are incorrect O The first statement is incorrect while the second statement is correct O The first statement is correct while the second statement is incorrect

Two proteins with the same amino acid composition do not have the same primary structure. Explain why.

Describe three major functions of proteins in the human body with one example for each.

Based on molecular weights of purified (no beta-Me) and (beta-Me) sample, which are 140 kDa and 72 kDa, what can be said about the number and size of the protein monomers, as well as the nature of the bonds holding together the complete quaternary structure of the proteins?

A mutation leads to a change in amino acid from valine, an amino acid with a nonpolar side chain, to aspartic acid, an amino acid with a polar, negatively-charged side chain. Do you think that the following levels of protein structure change? If so, how and why? If not, why not? Please frame your answer in terms of chemical bonds and interactions. (primary structure, secondary structure, tertiary structure, quartenary structure)

There are three possible levels of structure for a polypeptide:primary, secondary, and tertiary. Which of these has onlyone possible structure?

Explain why it is difficult to draw conclusions about the conformational changes of a protein based on a single crystal structure.