What is formed when multiple amino acid molecules join together by forming peptide bonds?

The structure of hemoglobin contains ......... heme groups.

The primary structure of a protein is determined by $..............$.

In the structure of secondary proteins,the folding of the polypeptide chain is caused by which bond?

How many types of amino acids are found in living organisms?

The triple helical structure of collagen was published in Nature in $1954$, and the analysis of the allowed conformations of proteins was performed through the use of the: