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Amino acids: zwitterions, isoelectric point
JEE Advanced level
Single correct option
Difficulty 3 of 3
bm077
The total number of stereocentres present in one molecule each of L-threonine, L-isoleucine, L-cysteine and glycine taken together is
A
5
B
3
C
4
D
6
Answer: A
Threonine has 2 stereocentres (C2 and C3), isoleucine has 2 (C2 and C3), cysteine has 1 (alpha-carbon) and glycine has 0. Total =
2
+
2
+
1
+
0
=
5
.
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