Concept explainers
(a)
Interpretation:
The
Concept introduction:
In mass spectroscopy, compounds can be identified on the basis of the mass of the compound. When the compound breaks into fragment then they can be distinguished from the other compounds. This technique is also used to differentiate the isotopes of compounds. In amino acids, three types of fragments are observed in low energy collisions are a, b and y ions. It is known as tandem mass spectrometry.
Answer to Problem 27.27P
The
Where N is asparagine, F is phenylalanine, E is glutamic acid, S is serine, G is glycine, K is lysine amino acid.
Explanation of Solution
In amino acids, b-type fragments appear due to an amino group or in other words charge is being carried by N-terminal. That is why it is also known as the N-terminus amino acid fragment. The b-type fragment is shown below.
Figure 1
The given peptide is
The
(b)
Interpretation:
The
Concept introduction:
In mass spectroscopy, compounds can be identified on the basis of the mass of the compound. When the compound breaks into fragment then they can be distinguished from the other compounds. This technique is also used to differentiate the isotopes of compounds. In amino acids, three types of fragments are observed in low energy collisions are a, b and y ions. It is known as tandem mass spectrometry.
Answer to Problem 27.27P
The
Where N is asparagine, F is phenylalanine, E is glutamic acid, S is serine, G is glycine, K is lysine amino acid.
Explanation of Solution
In amino acids, y-type fragments appear due to a carboxyl group or in other words charge is being carried by C-terminal. That is why it is also known as the C-terminus amino acid fragment. The y-type fragment is shown below.
Figure 2
The given peptide is
The
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Chapter 27 Solutions
EBK ORGANIC CHEMISTRY
- 22-61 Polyglutamic acid (a polypeptide chain made only of glutamic acid residues) has an a-helix conformation below pH 6.0 and a random-coil conformation above pH 6.0. What is the reason for this conformational change?arrow_forward22-49 Based on your knowledge of the chemical properties of amino acid side chains, suggest a substitution for leucine in the primary structure of a protein that would probably not change the character of the protein very much.arrow_forwardIdentify the following amino acid at pH = 7 (aqueous form): (COO-)–CH(NH3+)–CH2–(COO-) aspartic acid asparagine histidine arginine lysine Describe the amino acid illustrated above (at pH = 7.0). it is a non-polar, positively-charged amino acid it is a polar, positively-charged amino acid it is a polar, uncharged amino acid it is a polar, negatively-charged amino acid it is a non-polar, negatively-charged amino acid How many chiral carbons are present in the above amino acid (in aqueous form)? zero chiral carbons one chiral carbon two chiral carbons three chiral carbons four chiral carbons How many optical isomers (stereoisomers) are possible for the above amino acid (aqueous form)? 21 = 2 optical isomers 22 = 4 optical isomers 23 = 8 optical isomers 24 = 16 optical isomers 25 = 32 optical isomersarrow_forward
- Describe the tertiary and quaternarystructure of a protein.arrow_forwardPeptides can be separated using an ion-exchange column based on their isoelectric (pI) values. At which pH values would two different peptides, one with a pl of 5.6 and the other with a pl of 8.6, bind to a cation- and anion-exchange column? Each peptide may be capable of binding to each column at more than one pH value. anion-exchange column at pH = 4.0 pH = 6.5 pH = 10.1 cation-exchange column at = 4.0 pH pH = pH = 6.5 = 10.1 Answer Bank peptide B pl = 8.6 peptide A pl = 5.6arrow_forwardQ1)In the pH range 1.82 to 8.99, H2Arg+ is the principal form of arginine. Which is the second most prominent species at pH 6.0? At pH 5.0?Q2) (a) Draw the structure of the predominant form (principal species) of 1,3-dihydroxybenzene at pH 9.00 and at pH 11.00.(b) What is the second most prominent species at each pH?(c) Calculate the percentage in the major form at each pHarrow_forward
- The amino acid histidine has ionizable groups with pK₁ values of 1.8, 6.0, and 9.2, as shown. COOH H¸Ñ—CH CH₂ H 2 CH pH = COO™ H¸Ñ—CH 1.8 pk₁ CH₂ H lonizable -COOH = -COO- group CH COO™ H₂N-CH 6.0 pK₂2 CH₂ H -HisH -His N CH COO™ H₂N-CH 9.2 pk CH₂ H 2 —NH — —NH, CH A biochemist makes up 95 mL of a 0.13 M solution of histidine at a pH of 5.3. She then adds 60 mL of 0.10 M HCl. What is the pH of the resulting solution?arrow_forwardConsider the following peptide : Phe – Glu – Ser – Met and Val – Trp – Cys – Leu. Do these peptides have different net charges at (a) pH 1? (b) pH 7? Indicate the charges at both pH valuesarrow_forwardGiven below is the structure of a peptide with the name seryllysylaspartate. What is the amino acid at the C-terminus (or C-terminal amino acid) of this peptide? OH | CH, O || + H₂N-C | H O lysine Z-: serine + ŃH₂ T CH₂ T O aspartate CH₂ T CH₂ CH, O || N -C | O lysylaspartate H H C CH, O || C-O C-N C 1 H Harrow_forward
- . Describe the pH range of acceptable buffering behavior for the amino acids alanine, histidine, aspartic acid, and lysine.arrow_forwardComplete the following reaction: Naz-peptide -Peptide CA> ران CH CH3 CH3 NP₂ CH H' (hydrolysit) NA₂ V=0arrow_forwardSome Protein P binds to 1 molecule of X. The fractional binding curve (θ vs. [Ligand]) shows that θ = ⅓ when [X] = 6 mM. What is the Kd for X binding to P?arrow_forward
- Introduction to General, Organic and BiochemistryChemistryISBN:9781285869759Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar TorresPublisher:Cengage Learning