Amide group is present in

Which of the following is not a globular protein?

Amino acids are

Which of the following amino acids contains an imidazole ring?

When urea is heated,it forms biuret,the alkaline solution of which forms $.....$ with $CuSO_4$ solution.

Each polypeptide in a protein has amino acids linked with each other in a specific sequence. This sequence of amino acids is called . . . . . . structure of that protein.