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T gioups ol common amino acids are around a. pH 2 b. pH 5 c. pH 7 d. pH 9 2. Wha

ID: 97768 • Letter: T

Question

T gioups ol common amino acids are around a. pH 2 b. pH 5 c. pH 7 d. pH 9 2. What is the charge on the tetrapeptide lys-lys-his-glu at pH 7? a. 0 c. +2 d.-1 3. What is the predominant form of the amino acid abbreviated R at pH 7? a. positive b. neutral c. negative Exhibit 3A (for this chapter) Amino acid Ala Arg Asn or Gln Asp or Glu Cys His Ser Tyr -carboxyl group pK a 2.3 2.2 2.1 2.2 1.7 1.8 2.2 2.1 u-amino group pK, 9.7 9.0 9.0 9.8 10.8 9.2 9.2 9.1 R-group pk 12.5 4.0 8.3 6.0 10.1 4. Refer to Exhibit 3A. What is the order of the pls in increasing order (from acid to base)? a. Alanine, Arginine, Asparagine, Cysteine, and Aspartic Acid b. Aspartic Acid, Alanine, Asparagine, Cysteine, and Arginine c. Aspartic Acid, Cysteine, Asparagine, Alanine, and Arginine Arginine, Alanine, Asparagine, Cysteine, and Aspartic Acid e. Aspartic Acid, Cysteine, Arginine, Alanine, and Asparagine, 5. What is the predominant form of the amino acid abbreviated val at pli 7? a. positive b. neutral c. negative

Explanation / Answer

2. +1

3. Positive

4. For increasing order ffrom acid to base.
pI for Asp = 2.2+4/2 = 3.1
Arg = 9+12.5/2 = 21.5/2 = 10.7
Ala = 2.3+9.7/2 = 6
Asn = 2.1+9/2 = 5.5
Cys = 8.3+10.8/2 = 19.1/2 = 9.5

Order = Asp, Ala, Asn, Cys, Arg

5. Neutral

6.

7. D. Cys = 8.3+10.8/2 = 19.1/2 = 9.6

8. A. Both bonded to alpha carbon.

9. D. Alanine

10. B. Cys and Met

11. B. Ornithine - It don't have any code in mRNA sequence. So it not comes in protein structure.

12. A. Glutamic Acid - Acidic Amino acids have high -ve charge at pH 7

13. D

14. True. SH group of met is bond with methyl group.

15. A. Very water soluble. Only Ala is Hydrophobic Amino acids. Others are polar amino acids. Arg, His Basic amino acids, Ser hydroxyl Amino acids are involved in hydrogen bond with water

16. B.

17. C. Peptide bond contain both Co and NH group.

18. D

19. B

20. D Peptide bond formed between amino and carboxy group undergo condensation.