Question

Proteins are made up of
​

Answer 1

Proteins are made up of hundreds or thousands of smaller units called amino acids

which are attached to one another in long chains.
There are 20 different types of amino acids that can be combined to make a protein.

Answer 2

Answer:

${\boxed{\boxed{\tt { Amino / Acids}}}}$

Explanation:

Proteins are organic molecules composed of Carbon, Hydrogen, Oxygen and Nitrogen. Proteins are created by linking together amino acids into protein links called polypeptide chains.