Answer is thousands of different proteins
Proteins are macro-molecules, made up of small units or building blocks. These building blocks are called amino acids. To build a protein, first the amino acids are connected into long chains, called polypeptide chains. These chains of amino acids fold into all types of shapes. Some chains fold into spirals. Combining these spirals, sheets, and loops is how the three-dimensional shape to build a functional protein. The human body uses just 20 amino acids to make all the proteins it needs to function and grow. Because amino acids can be arranged in many different combinations, it's possible for our body to make thousands of different kinds of proteins from just the same 20 amino acids.
