A β -pleated sheet organization in a polypeptide chain is an example of
A β -pleated sheet organization in a polypeptide chain is an example of
The correct option is B 2∘ structure
Four basic structural level are assigned to proteins-primary, secondary, tertiary and quaternary structures.
The primary structure of a protein refers to the linear sequence of amino acids in the polypeptide chains and location of disulphide bridges if there are any. In representing the primary structure, the N-terminal amino acid is always written on the left end of the polypeptide chain and C-terminal amino acid at the right end of the chain.
The folding of a linear polypeptide chain into a specific coiled structure is referred to as the secondary structure of the protein. Such coiling or folding is produced by hydrogen bonds. The importance of such folding lies in the fact that amino acid residues which may lie far apart in their primary sequence are brought together in close proximity by secondary folding. There are three types of secondary structures
α-helix
β-pleated sheets
Collagen helix.
In α-helix, the polypeptide chain is coiled spirally, generally in right handed manner e.g., keratin (hair), myosin, tropomyosin (muscles), etc.
In β-pleated secondary structure, two or more polypeptide chains get interconnected by hydrogen bonds. Adjacent strands of polypeptides may run in the same direction (parallel b-sheet, e.g.,keratin) or in opposite directions (antiparallel b-sheet, e.g., fibroin of silk).
2∘ structure
Four basic structural level are assigned to proteins-primary, secondary, tertiary and quaternary structures.
The primary structure of a protein refers to the linear sequence of amino acids in the polypeptide chains and location of disulphide bridges if there are any. In representing the primary structure, the N-terminal amino acid is always written on the left end of the polypeptide chain and C-terminal amino acid at the right end of the chain.
The folding of a linear polypeptide chain into a specific coiled structure is referred to as the secondary structure of the protein. Such coiling or folding is produced by hydrogen bonds. The importance of such folding lies in the fact that amino acid residues which may lie far apart in their primary sequence are brought together in close proximity by secondary folding. There are three types of secondary structures
α-helix
β-pleated sheets
Collagen helix.
In α-helix, the polypeptide chain is coiled spirally, generally in right handed manner e.g., keratin (hair), myosin, tropomyosin (muscles), etc.
In β-pleated secondary structure, two or more polypeptide chains get interconnected by hydrogen bonds. Adjacent strands of polypeptides may run in the same direction (parallel b-sheet, e.g.,keratin) or in opposite directions (antiparallel b-sheet, e.g., fibroin of silk).
