m ical reactions 8) Which of the following represents an amino acid in a basic solution...
Amino Acids SW C2 9. Which of the following is an L-amino acid? çoo coo coo HẠN |-R HANH, HẠN –H HÀNH R coo B. 10. The following questions refer to the structures A-E below: (a) Which represents the structure of an amino acid at very high pH? (b) Which is a zwitterion? (c) Which represents the structure of an amino acid at very low pH? (d) Which structure/(s) is/are) not possible? R-CH-COOR-CH-COOH R-CH-COOH R-CH-COOR -CH-COO NH2 NH2 *NH NH2...
explain the following answers 8. (3 pts) Consider the structure of histidine, shown below, along with the three pk, values of the three acidic groups. What is the isoelectric point (pl) for histidine? NH2 pka COOH = 1.77 = 6.10 pka, NH3+ = 9.18 pka, ning A) 3.94 C) 5.68 B) 5.48 D) 7.64 histidine OH 9. (3 pts) Which one of the following forms of histidine is the form that would mainly exist near pH = 4? HN NH2...
1) Which of the following is an amino acid? A) e R-CH-CH2-C00R -CH-CooR -CH-C-CO ile R-CH-C-NH3 R-C=CH-Coo NH3 NH3 NH3 ONH 3 D) coo B) E) 2) Which of the following amino acids has a sulfur in the R group? A) serine B) cysteine C) asparagine D) tyrosine E) leucine 3) Which of the following terms describes the side chain of valine? A) acidic B) basic C) charged, polar D) uncharged, polar E) nonpolar 4) Which of the following is...
(1) The following diagram represents a titration curve of histidine as pH increases; pKa = 1.82 represents the terminal carboxylic acid group. pK, represents the terminal amino group: 6.0 represents the R-group, and pK, E 9.17 7.59 pH 182 3.0 20 10 H (equivalents) At what point on the diagram is histidine predominantly present as the following species? COO A, at pH < 1.82 B. between pH 1.82 and pH 6.0 C) between pH 6.0 and pH 9.17 D. at...
A8 The acid dissociation constants (pKa) of the amino acid aspartic acid are shown below. What is the isoelectric point (pl) of this amino acid? pk, 9.8 ΤΗΝ PK, 2.1 TOH OS pk 3.9 ОН (A) 6.9 (B) 6.0 (C) 3.9 (D) 3.0 (E) 2.1
14) Which of the following amino acids will by cation-exchange chromatography? following amino acids will be retained longest in the column when sepa Η serne HO-CH-C-COO v. Lysine H3N-CH2CH2CH2CH2CH-co NES NH V. Phenylalanine CH-C–COOH II. Alanine CH3-C-Coo II. Cysteine HS-CH-c-coo® NE 15) What is the product obtained from mild oxidation of the thiol shown below? mild 2R-SH oxidation A) R-S- R B) R-OH C) R-S-S-R DR-OO- RE ) R-S-OH 16) Which bond in the following compound is a peptide bond?...
Which of the following amino acids will be retained longest in the column when separated by cation-exchange chromatography? H 1. Serine HO-CH2-C-COO® IV. Lysine NH H3N-CH2CH2CH2CH2CH -COOH NH H H V. Phenylalanine -CH--COOH NH II. Alatine Chy-d-coop H II. Cysteine HS-CH -¢-Coo® NH О О О О О IV V
2) At a pH greater than that of its isoelectric point, the structure of glycine is a) H-CH-COOH b) H-CH-C00- c) H-CH-CO e) H-CH-COO COOH b) H-CH-C00- c) H-CH-COOH d) H-CH-COO NH2 NH2 NH2 NH3 NH 3) Which of the following structures can be destroyed by the dena structures can be destroyed by the denaturation of a protein? a) Only primary and tertiary structures of a protein. b) Only secondary, tertiary y secondary, tertiary, and quaternary structures of a protein....
5. What is the pl of the following amino acid? a) 1.2 b) 3.2 c) 5.5 d) 6.2 e) 7.0 NH2 pKal 2.4pKa2-10.0 pKa3-4.0 R group α-NH
26. Which of the following classification does not match the amino acid side chain A) Contains an basic group/ lysine B) It is polar C) Forms disulfide bond/ cysteine D) Forms hydrogen bonds with neighbors/ alanine serine 27. All amino acids found in proteins are L-amino acids EXCEPT the achiral. A) glutamate B) Lysine C) glyeine D) Alamine 28. The plH at which the positive and negative charges of an amino acid balance each ofher is called the A) isotonic...