Question

What do amino acids have in common?

Answer 1

We also remember that the amino acids are monomers which form a basic unit for polymers and they make up protein. They are also known as building blocks of protein. In our body amino acids are used by each and every cell to form proteins which are needed by every cell for their survival and every living organism requires amino acids for basic chemical building blocks.

Complete answer:
As we know that all the amino acids have an amino group, a carboxyl group and a variable group.
Amino group: Amino group is the most versatile nucleophile in peptide synthesis. Amino groups have high reactivity and hence they take excess side reactions during peptide synthesis. Most of the side reactions are acetylation, formylation, trifluoroacetylation and alkylation. All the amino acids are organic molecules that are made up of a basic amino group.
A carboxyl group: Carboxyl group is made up of one carbon and two oxygen atoms and it is negatively charged. Carboxyl group is commonly found in all the amino acids. Carboxyl group of one amino acid is attached to the amino group of another amino acid and it forms the chain of amino acids and this chain is used to build protein molecules.
All the amino acids show amino group and carboxyl group in common and the thing which makes amino acids different from one another is the variable group which is also known as R-group. The variable group of each amino acid is different.

Note:
We must know that each amino acid has a similar fundamental structure and amino acids consist of a central carbon atom which is also known as alpha $\left( \alpha \right)$ carbon, which are bonded to the amino group, carboxyl group and hydrogen atom. Every amino acid has a group of atoms bonded to the central atom and is known as the R group.