Amino group

The amine group is characterized by the presence of a nitrogen atom with a pair of non-bonding electrons. It is derived from ammonia, where one or more hydrogens have been replaced by other atoms.

The amines can be divided into primary, secondary and tertiary. The primaries are those in which only one of three hydrogen atoms of ammonia was replaced by an alkyl chain. The secondary amines have two alkyl chains and the tertiary have three. The secondary and tertiary amines may be presented in a linear or cyclic form.

The amines may be designated in different ways. Typically, it is used the prefix amino-("aminoacid", for example) or the suffix-amine ("glucosamine," for example). When there is a substitution in the amino group, it is named starting with the prefix N-.
The amines can establish hydrogen bonds, since they have one H atom attached to a very electronegative atom (N in this case).
The amines act as weak bases, as they can capture a H+, due to the existence of a pair of non-bonding electrons in the nitrogen atom. They are the most relevant alkaline functional group in biochemistry.