Question
Which of the following is having Maximum buffering capacity
A. Histidine
B. Cysteine
C. Tyrosine
D. Arginine
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Correct Answer » A Explanation |
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Answer-A- Histidine
Maximum buffering capacity occurs at a pH equal to the pKa,
So amino acid which has pKa range near physiologic pH can act as an effective buffer
* lmidazole group of histidine – 6.5- 7.4 pKa range
* SH group of cysteine→ 8.5-9.0 pKa range
* OH group of tyrosine → 9.5-10.5 pKa range
* Arginine → > 12