Answer the following question given this paragraph: 

The reverse reaction (amide hydrolysis) is very useful in the study of protein structure. Proteins are long chains of amino acids (each amino acid contains an amine group and a carboxyl group, both attached to a central carbon atom). The amino acids are linked together by amide bonds to form the long protein chain. One of the techniques for looking at protein structure is to break those amide linkages so we can learn the identity of the amino acids in the chain. We do this through a hydrolysis reaction:.


Q: What are long chains of amino acids?

 Choices:

- lipids

- Fatty Acid Chains

- cells

- proteins

A:
proteins
