Question

15 Thermodynamic parameters (entropy, enthalpy free energy, and internal energy) are given for an unknown chryme Explain which results would be expected for the breaking of hydrogen bonds and the exposure of hydrophobie groups from the interior during the unfolding process of a protein. B1 A B. C. D. E. Entropy change, AS, is zero. Enthalpy change, AH, is positive. The reaction is spontaneous. Enthalpy change, AH, is negative. Entropy change, AS, is positive. Insulin is a polypeptide hormone that contains two short polypeptide chains linked by two interstrand disulfide bonds. The most logical order of events to perform in order to sequence this protein would be: a: The peptides are reduced with mercaptoethanol. b: The peptides are sequenced using Edman chemistry. c: The peptides are separated by chromatography techniques. d: The peptides are alkylated with iodoacetamide. (0) A. B. c. D. E and, by Ved, b c, b,a,d a, b, c, d, a, d, e, Determine the amino acid sequence of the following oligopeptide from the experimental data below. - The peptide has a molecular weight around 700 Da and absorbs at 280 nm. Treatment with carboxypeptidase (removes the C-terminal residue) results in tryptophan and a peptide. CNBr treatment yields a tetrapeptide and a dipeptide 4 - 2 Trypsin digestion produces an amino acid and a pentapeptide with met on the amino end. Chymotrypsin digestion yields a dipeptide and a tetrapeptide. AT A. B c. D. E. Ala-Met-Lys-Cys-Phe-Trp 18 Ala-Phe-Met-Cys-Top Lys-Ala-Cys-Met-Phe-Trp Cys-Met-Cys-Ala-Phe-Trp Lys-Met-Cys-Phe-Ala-Trp
15,16,17

Answer 1

15) the entropy change del S will be positive.because then the randomness of the protein molecules will be increased becasue the h bond is broken which stabilizes the structure of proteins. the reaction is spontaneous or not you cant tell because there is no data for enthalpy. similarly, enthalpy can be positive or negative.

16)the answer will be the option 1 because first protein has to be cleaved by the mercaptoehanol which will cleave the disulfide bond and make single polypeptide

then it should be separated and then it should be acted by idoacetate and finally if should be performed

edman sequencing .

17) the first cue is similar as every peptide sequences contain 6 amino acids.

carboxypeptidase treatment results in a trytophan and a pentapeptide which means the peptide must have c terminal tryptopham amino acid which is common in every options.

CNBr treatment produces a tetrapeptide and a dipeptide as we know that CNBr only cut after methinine so in peptide sequences met should have in 4th position. so option A ,D and E cab be the sequences.

as trypsin cut after lysine and here option D an E can be the answer becasue then only one amino acid will be produced and one pentapeptide will be produced which will have met on amino terminal end.

as carbosypeptidase cut after aromatic amino acid here E is the answer because then only two peptides one is dipeptide and another will be tetrapeptide because phenylalanine is a aromatic amino acid.in case of option D ,phenylalanine is present in 5th position so if we traet this with chymotrypsin then one amino acid and one pentapeptide will be produced which is not the case .

thank you