Jee Advanced
Biomolecules
IIT-JEE 2012 Paper 1 Offline
INTEGER+3 / -02012
The substituents R1 and R2 for nine peptides are listed in the table given below. How many of these peptides are positively charged at pH = 7.0 ?
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| Peptide | \({R_1}\) | \({R_2}\) |
|---|---|---|
| I | H | H |
| II | H | \(C{H_3}\) |
| III | \(C{H_2}COOH\) | H |
| IV | \(C{H_2}CON{H_2}\) | \({(C{H_2})_4}N{H_2}\) |
| V | \(C{H_2}CON{H_2}\) | \(C{H_2}CON{H_2}\) |
| VI | \({(C{H_2})_4}N{H_2}\) | \({(C{H_2})_4}N{H_2}\) |
| VII | \(C{H_2}COOH\) | \(C{H_2}CON{H_2}\) |
| VIII | \(C{H_2}OH\) | \({(C{H_2})_4}N{H_2}\) |
| IX | \({(C{H_2})_4}N{H_2}\) | \(C{H_3}\) |