Case: Read the passage and answer the following questions

Protein structure is the three-dimensional arrangement of atoms in an amino acid-chain molecule. Proteins are polymers – specifically polypeptides – formed from sequences of amino acids, the monomers of the polymer. A single amino acid monomer may also be called a residue indicating a repeating unit of a polymer. A monopeptide has one amino acid. A dipeptide has two amino acids. A tripeptide has three amino acids. A tetrapeptide has four amino acids. The complete structure of a protein can be described at four different levels of complexity: primary, secondary, tertiary, and quaternary structure.

In which sequence the amino acids are arranged in a protein? 

Primary

The primary structure of a protein — its amino acid sequence — drives the folding and intramolecular bonding of the linear amino acid chain, which ultimately determines the protein's unique three-dimensional shape.