Achain is a sequence of amino acids that is the foundation for the basic structure of a protein.

A polypeptide chain is a sequence of amino acids that is the foundation for the basic structure of a protein.

Explanation:

The amino acids are composed of an organic molecule with an amino group and a carboxyl group. Its combination forms proteins, which are essential for our body. They are formed of carbon, oxygen, hydrogen and nitrogen. Among its functions, amino acids help break down food and repair body tissues.

Proteins consist of one or more amino acid chains; These chains are called polypeptides. These are peptides when the chains are composed of at least ten amino acids. Then a polypeptide, in other words, is a sequence of amino acids that are linked through peptide bonds. If the chained amino acids are more than a hundred, then we talk about protein.  Proteins, therefore, are made of polypeptide chains.

Generally a polypeptide contains between 50 and 100 amino acids.

So:

A polypeptide chain is a sequence of amino acids that is the foundation for the basic structure of a protein.

a) are muscles that have bands.

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