Question
Question: Most common types of secondary structure of proteins are...
Most common types of secondary structure of proteins are
A
α− helix and β−helix structures
B
α−helix and β−helix sheet structures
C
Right and left hand twisted structures
D
Globular and fibrous structures
Answer
α−helix and β−helix sheet structures
Explanation
Solution
Due to regular folding of backbone of the peptide chain, two most common secondary structures of proteins are α− helix and β− plated structures. In α− helix, all H – bonds are formed by twisting the chain into a right handed helix. In 
all peptide chains are stretched to maximum extension and then laid side by side and connected by hydrogen bonds.