
Concept explainers
(a)
Interpretation: The reagents used in the determination of the amino acid sequence of a small peptide should be determined.
Concept Introduction: A peptide bond is present between the two amino acids in a protein. During the formation of a peptide bond, a molecule of water is released. The amino group of an amino acid gets associated with the carboxyl group of another. Polypeptides and proteins are the chains formed by the amino acids.
(a)

Answer to Problem 1P
The reagent used in the determination of the amino acid sequence of a small peptide is phenyl isothiocyanate.
Explanation of Solution
The reagent used in the determination of the amino acid sequence of a small peptide is phenyl isothiocyanate.
Phenyl isothiocyanate shows a reaction with an uncharged N-terminal amino group. It occurs under the slightly alkaline conditions and forms a cyclical phenyl thiocarbamoyl derivative. It can sequence up to 30 amino acids accurately with modern machines. It is proficient of over 99% proficiency per amino acid.
(b)
Interpretation: The reagent that can undergo reversible denaturation if a protein lacks disulfide bonds should be determined. Also, the reagent needed when the disulfide bonds are present should be determined.
Concept Introduction: A peptide bond is present between the two amino acids in a protein. During the formation of a peptide bond, a molecule of water is released. The amino group of an amino acid gets associated with the carboxyl group of another. Polypeptides and proteins are the chains formed by the amino acids.
(b)

Answer to Problem 1P
The reagent for the reversible denaturation is urea. Beta-mercaptoethanol is used to reduce the disulfide bonds.
Explanation of Solution
The reagent that can undergo reversible denaturation if a protein lacks disulfide bonds is urea.
If the disulfide bonds are present, then the reagent needed is beta-mercaptoethanol. This reagent is used to reduce the disulfide bonds.
(c)
Interpretation: The reagent useful for the peptide bonds hydrolysis present on the carboxyl side of
Concept Introduction: A peptide bond is present between the two amino acids in a protein. During the formation of a peptide bond, a molecule of water is released. The amino group of an amino acid gets associated with the carboxyl group of another. Polypeptides and proteins are the chains formed by the amino acids.
(c)

Answer to Problem 1P
The reagent required is chymotrypsin.
Explanation of Solution
The reagent useful for the peptide bonds hydrolysis present on the carboxyl side of aromatic residues is chymotrypsin which specifically cleaves the C-terminal side of aromatic acid residues.
(d)
Interpretation: The reagent useful for the peptide bonds cleavage on the carboxyl side of methionine should be determined.
Concept Introduction: A peptide bond is present between the two amino acids in a protein. During the formation of a peptide bond, a molecule of water is released. The amino group of an amino acid gets associated with the carboxyl group of another. Polypeptides and proteins are the chains formed by the amino acids.
(d)

Answer to Problem 1P
The reagent useful for thepeptide bonds cleavage on the carboxyl side of methionine is CNBr or cyanogen bromide.
Explanation of Solution
The reagent useful for the peptide bonds cleavage on the carboxyl side of methionine is CNBr. It is also known as cyanogen bromide. It is a solid and colorless inorganic compound. It is extensively used to change the biopolymers, fragment proteins and peptides. It generally cleaves the C-terminus of methionine and produces other compounds.
(e)
Interpretation: The reagent for hydrolysis of peptide bonds on the carboxyl side of lysine and arginine residues should be determined.
Concept Introduction: A peptide bond is present between the two amino acids in a protein. During the formation of a peptide bond, a molecule of water is released. The amino group of an amino acid gets associated with the carboxyl group of another. Polypeptides and proteins are the chains formed by the amino acids.
(e)

Answer to Problem 1P
The reagent for hydrolysis of peptide bonds on the carboxyl side of lysine and arginine residues is trypsin.
Explanation of Solution
The reagent for hydrolysis of peptide bonds on the carboxyl side of lysine and arginine residues is trypsin.
Trypsin is generally formed in the small intestine. It is formed by the activation of trypsinogen. Trypsin usually cuts the peptide chains primarily at the carboxyl side of the lysine or arginineamino acids. It is used for many
Want to see more full solutions like this?
Chapter 3 Solutions
Biochemistry
- Do sensory neurons express ACE2 or only neurolipin-1 receptors for COVID19 virus particle binding?arrow_forwardExplain the process of CNS infiltration of COVID19 through sensory neurons from beginning to end, including processes like endocytosis, the different receptors/proteins that are involved, how they are transported and released, etc.,arrow_forwardH2C CH2 HC-COOO CH2 ܘHO-C-13c-O isocitrate C-S-COA H213c CH2 C-OO 13C-S-COA CH2 C-00 the label will not be present in succinyl CoA C-S-COA succinyl-CoAarrow_forward
- A culture of kidneys cells contains all intermediates of the citric acid cycle. It is treated with an irreversible inhibitor of malate dehydrogenase, and then infused withglucose. Fill in the following list to account for the number of energy molecules that are formed from that one molecule of glucose in this situation. (NTP = nucleotidetriphosphate, e.g., ATP or GTP)Net number of NTP:Net number of NADH:Net number of FADH2:arrow_forward16. Which one of the compounds below is the final product of the reaction sequence shown here? OH A B NaOH Zn/Hg aldol condensation heat aq. HCI acetone C 0 D Earrow_forward2. Which one of the following alkenes undergoes the least exothermic hydrogenation upon treatment with H₂/Pd? A B C D Earrow_forward
- 6. What is the IUPAC name of the following compound? A) (Z)-3,5,6-trimethyl-3,5-heptadiene B) (E)-2,3,5-trimethyl-1,4-heptadiene C) (E)-5-ethyl-2,3-dimethyl-1,5-hexadiene D) (Z)-5-ethyl-2,3-dimethyl-1,5-hexadiene E) (Z)-2,3,5-trimethyl-1,4-heptadienearrow_forwardConsider the reaction shown. CH2OH Ex. CH2 -OH CH2- Dihydroxyacetone phosphate glyceraldehyde 3-phosphate The standard free-energy change (AG) for this reaction is 7.53 kJ mol-¹. Calculate the free-energy change (AG) for this reaction at 298 K when [dihydroxyacetone phosphate] = 0.100 M and [glyceraldehyde 3-phosphate] = 0.00300 M. AG= kJ mol-1arrow_forwardIf the pH of gastric juice is 1.6, what is the amount of energy (AG) required for the transport of hydrogen ions from a cell (internal pH of 7.4) into the stomach lumen? Assume that the membrane potential across this membrane is -70.0 mV and the temperature is 37 °C. AG= kJ mol-1arrow_forward
- Consider the fatty acid structure shown. Which of the designations are accurate for this fatty acid? 17:2 (48.11) 18:2(A9.12) cis, cis-A8, A¹¹-octadecadienoate w-6 fatty acid 18:2(A6,9)arrow_forwardClassify the monosaccharides. H-C-OH H. H-C-OH H-C-OH CH₂OH H-C-OH H-C-OH H-C-OH CH₂OH CH₂OH CH₂OH CH₂OH D-erythrose D-ribose D-glyceraldehyde Dihydroxyacetone CH₂OH CH₂OH C=O Answer Bank CH₂OH C=0 HO C-H C=O H-C-OH H-C-OH pentose hexose tetrose H-C-OH H-C-OH H-C-OH aldose triose ketose CH₂OH CH₂OH CH₂OH D-erythrulose D-ribulose D-fructosearrow_forwardFatty acids are carboxylic acids with long hydrophobic tails. Draw the line-bond structure of cis-A9-hexadecenoate. Clearly show the cis-trans stereochemistry.arrow_forward
- BiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage LearningBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxBiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage Learning
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage LearningHuman Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage LearningBiology: The Unity and Diversity of Life (MindTap...BiologyISBN:9781337408332Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa StarrPublisher:Cengage Learning





