Cysteine and methionine are amino acids containing $........$.

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:

Which of the following is a group of sulfur-containing amino acids?

$A$ substance forms a Zwitter ion. It can have which of the following functional groups?

Which of the following compounds shows aromatic properties?

What type of amino acids are phenylalanine and tyrosine,respectively?