Formation of proteins
In chemical terms we say: the proteins are made in a polycondensation process, where the amino acids are the 'monomeres'.
You may consider proteins as a co-polymerisation product becaus normally different amino acids participate (there are about 20 different amino acids) in the process.
The whole synthesis can also be considered in another way: as a process that is controled by DNA/RNA.
That topic will com furtheron.
In the next scheme you can see the participating amino acids as double ions. (this appearance does not influence at all the condensation process.
At the two ends of such a dipeptide bond you still can see: an amino group and a carboxylic group.
In other words: the possibility exists to continue the process.
Again these groups can 'condensate' with other amino acids and form tri, tetra- oligo- or polypeptides.
A protein can consist of 50 tot 2000 joined amino acids; the molecular mass varies between 5000 and 20000.