Question

Which of the following structures is not common in all protein_____________?
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure

Answer 1

Hint:-Protein are the vital biomolecules that are made up of one or more long chains of smaller constituents which are the amino acids. The proteins are required to perform various activities such as catalyzing metabolic reactions, providing structure to the cells and transporting of molecules.

Complete Answer:-
Proteins are made up of long chains of amino acid residues which are called polypeptide chains. The peptides are considered as short chains of amino acids which are linked together by bonds which are known as peptide bonds. The individual amino acids residues are bonded together with the peptide bonds.
Proteins are folded into unique structures and it naturally folds to give rise to distinct structures. The basic shape of the proteins is responsible for the orientation as well as formation of the amino acid chains. The proteins can be classified into three into three basic types of structures which are primary structures, secondary structures and tertiary structures.
Primary structures are the most basic type of structure and it consists of simplest types of unbranched monomers. The primary structure consists of the amino acid sequences and are present commonly in all types of proteins.
Secondary structure is formed by repeatedly repeating sequences which are held and stabilized by the hydrogen bonds. The most common types of secondary structures are the α- helix and β-pleated sheets. They are local structures and are present in several regions of the protein molecules.
Tertiary proteins represent the overall shapes of the single protein molecules and they serve to control and regularize the basic functions of the proteins.
Quaternary protein structures are formed when several protein molecules are joined that they function as a single protein molecule or complex. These protein molecules are also referred to as the protein subunits. The quaternary shape of proteins are not present in different types of proteins and so, they are not found in all types of proteins.
Thus, the right option is D.

Note:- The structure of the protein is important and affects the functional viability of the proteins. Proteins are formed by condensation reactions which creates peptide bonds between the amino acid sequences. The different structures of the proteins are primary, secondary, tertiary and quaternary structures. The quaternary structure of proteins is not commonly found in all types of proteins.