Answer the following question given this paragraph: 

Proteins are nutrients made up of smaller molecules called amino acids . Recall that there are 20 different amino acids arranged like "beads on a string" to form proteins. These amino acid chains then fold up into a three-dimensional molecule, giving the protein a specific function. Proteins have several important roles in the body. For example, proteins make up antibodies, muscle fibers and enzymes that help control cell and body processes. You need to make sure you have enough protein in your diet to obtain the necessary amino acids to make your proteins.


Q: How many amino acids are arranged like "beads on a string" to form proteins?


A:
20