Which of the following is the major solute species in a solution of glutamic acid at $\mathrm{pH}=4.3$? (Isoelectric point of glutamic is at $\mathrm{pH}=5.6$).

Which of the following statements about amino acids are not true?

(a) They are low melting crystalline solids.

(b) Most naturally occurring amino acid have L-configuration.

(c) Isoelectric point of neutral amino acids lie at $\mathrm{pH}$ between $5.5$ to $6.3$.

(d) Glycine is the only naturally occurring $\mathrm{\alpha }$-amino acid which is optically active.

Which of the list shown below have the correct pair of the structure of alanine in $\mathrm{pH}$ ranges $2-4$ and $9-11$ is

I. ${\mathrm{H}}_3\stackrel{+}{\mathrm{N}}-\mathrm{CH}\left({\mathrm{CH}}_3\right){\mathrm{CO}}_2\mathrm{H}$

II. ${\mathrm{H}}_2\mathrm{N}-\mathrm{CH}\left({\mathrm{CH}}_3\right){\mathrm{CO}}_2^{-}$

III. ${\mathrm{H}}_3\stackrel{+}{\mathrm{N}}-\mathrm{CH}\left({\mathrm{CH}}_3\right){\mathrm{CO}}_2^{-}$

IV. ${\mathrm{H}}_2\mathrm{N}-\mathrm{CH}\left({\mathrm{CH}}_3\right){\mathrm{CO}}_2\mathrm{H}$

Which set of the terms correctly identifies the carbohydrate shown?

(i) Pentose                  (ii) Hexose               (iii) Aldose

(iv) Ketose                  (v) Pyranose             (vi) Furanose