Question

5. Show how an amino group and a carboxyl group can interact to form an H-bond.

Answer 1

There are three possibility to make H bond between carboxyl group and amino group.

1St possibility :

Amino group have H atoms attached to N atom which is a high electronegative atom.

On the other hand carboxyl group have O atom doubly bonded to carbon which interacts with H atom attached with the N atom hence forming H bond.

2nd possibility :

There is OH group in carboxyl group, this H of OH group can form H bond with the N atom of amino group.

3rd possibility:

The H atoms attached to N can also form H bond with the O of OH group of carboxyl group.

Hence, there are three possible H bonds. But if these all are present between these two groups then there is a large stearic hindrance. So, we cannot say which bonds will be present and also cannot show proper orientation of these H bonds by diagram .