Question

The polypeptide chain in a protein has amino acids linked with each other in a specific sequence. This specific sequence of amino acids is called:

• A. Primary structure of protein
• B. Secondary structure of protein
• C. Tertiary structure of protein
• D. Quaternary structure of protein

Hint:

Primary structure = {Sequence}. If sequence changes → protein function may change.

Answer 1

The Correct Option is A

The specific sequence of amino acids in a polypeptide chain of a protein is referred to as the primary structure of the protein. This concept is crucial in understanding how proteins are built and function. Here's a breakdown of why the primary structure is the correct answer and a brief explanation of why the other options are incorrect:

1. Primary structure of protein: The primary structure is the linear sequence of amino acids in a polypeptide chain. This sequence determines the protein's unique characteristics and function because the order of amino acids influences the way the protein will fold into its higher-order structures.
2. Secondary structure of protein: This refers to the local sub-structures formed by hydrogen bonds between the backbone atoms in the polypeptide chain. Common secondary structures include alpha helices and beta sheets. These are not about amino acid sequence but rather about how parts of the sequence interact with each other.
3. Tertiary structure of protein: The tertiary structure is the overall three-dimensional shape of a single protein molecule. The spatial arrangement results from interactions between secondary structures and other chemical interactions. It’s the tertiary folding that often determines a protein’s function.
4. Quaternary structure of protein: This structure is relevant for proteins with more than one polypeptide chain. It describes how these chains (subunits) are arranged with respect to each other within the protein complex.

Since the question specifically asks for the sequence of amino acids, the primary structure is the definitive answer. Understanding these structural levels in proteins is essential because they dictate the protein's function and its interactions within the body.