Biomolecules and Chemistry in Everyday Life - Result Question 48

####9. The correct structure of histidine in a strongly acidic solution $(pH=2)$ is

(2019 Main, 12 Jan II)

(a)

(c)

(b)

(d)

Show Answer

Answer:

Correct Answer: 9. (c)

Solution:

  1. Histidine has following structure in

At highly acidic $pH$, i.e. 2 both the nitrogens with lone pairs will accept one $H^{+}$each and $-C-OH$ will not loose its $H^{+}$. Thus,

the final structure of histidine at $pH=2$ will be

Thus, option (d) is the correct answer.

Note Amino acids have following generalise structure:

They have the tendency to loose $H^{+}$of their $-COOH$ group at alkaline (higher) $pH$ while the $-NH _2$ group present in them have the tendency to gain $H^{+}$at acidic (lower) $pH$.



जेईई के लिए मॉक टेस्ट

एनसीईआरटी अध्याय वीडियो समाधान

दोहरा फलक