A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure

A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure

A. Primary structure
B. Secondary structure
C. Tertially structure
D. Quaternary structure

A. Primary structure
B. Secondary structure
C. Tertiary structure.
D. Quaternary structure

A. Peptide linkage
B. Alkyle linkage
C. Trilinkage
D. Keto linkage

A. Berzelius
B. Laveron
C. Nicholson
D. Singer

A. Amino acids
B. Benzoic acids
C. Alkyle acids
D. Keto acids

A. Ester bond
B. Amide bond
C. Carboxylic bond
D. Aldehyde bond

A. Amind bond
B. Ester bond
C. Carboxylic bond
D. Aldehyde bond

A. Radial groups
B. Functional groups
C. Non-functional groups
D. tonic groups