When protein cannot precipitate out under the conditions for making tofu and cheese because (i) polar groups are highly abundant in the surfaces of whey proteins; and (ii) disulfide bonds are commonly present in the structures of whey proteins. Explain briefly why highly abundant polar groups and disulfide bonds could make whey proteins resist precipitation of protein molecules. (i) Under the condition where the environmental pH is equal to the isoelectric point of whey protein (ii) Under the condition where rennet is added to whey protein solution

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?

A protein gives, under conditions of buffer composition, pH, and temperature that are  close to physiological conditions, a molecular weight by sedimentation equilibrium  measurements of 140,000 g/mol. When the same protein is studied by SDS gel  electrophoresis in the absence or presence of the reducing agent β-mercaptoethanol  (BME), the patterns seen in lanes A and B respectively are observed. Lane C contains  standards of molecular weight indicated. From these data, describe the native protein,  in terms of the kinds of subunits present, the stoichiometry of subunits (that is, how  many of each subunits are present), and the kinds of bonding (covalent, non-covalent)  existing between subunits

if the tetrapeptide shown in the binding site above (Gly-Ser-His-lle) were in an aqueous solution at pH=6.2, what fraction of peptide molecules would have a +1 charge?

Which of the following amino acids would you least expect to find on the surface of a water-soluble protein? Explain I Serine Glutamat Lysime Threonine