Answer: Because they cannot be synthesized inside the body.
Explanation: The amino acid are the basis for the protein synthesis in the body. The protein regulates the various processes of the body.
There are two types of amino acids found in the body. One of them is essential amino acids as it cannot be synthesized inside the body and it must be taken by the food that we eat.
The other form of amino acids are non essential amino acids that are synthesized in the body itself and we need not to take it from the outer sources.
