Are amino acids other than the usual 20 amino acidsfound in proteins? If so, how are such amino acids incorporatedinto proteins? Give an example of such an amino acid and a protein in which it occurs.

Estimate the PI of the given amino acid? Assume that the amino acid contains a single carboxylic acid group on the side chain.

Why do proteins hold their shape?

Proteins that are synthesized by living organisms adopt abiologically active conformation. Yet when such moleculesare prepared in the laboratory, they usually fail to spontaneously adopt their active conformations. Can you suggestwhy?

Draw one sample structure of the following types of amino acids: acidic amino acid, basic amino acid, non-polar amino acid polar, uncharged amino acid.

What are the building blocks of proteins? What type ofbond chemically connects these building blocks? What isthe importance of the R group?

When an inappropriate amino acid is substituted in place of another, as occurs in certain genetic disorders, the resulting protein is either poorly functional or non-functional. Since proteins contain hundreds if not thousands of amino acids, why should the change of a single amino acid be so critical?

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

It is observed that as temperature is increased, most protein molecules gofrom their defined, folded state into a random-coil, denatured state thatexposes more hydrophobic surface area than is exposed in the folded state.(a) Given what you have learned so far about ΔH and ΔS, explain why thisis reasonable. (b) Sometimes, however, proteins denature as temperature is decreased.How might this be explained?

What are the "N" and "C" termini of proteins?