Protein Structure Levels: Primary — NEET Biology
📚 Practice ConceptProteins, as mentioned earlier, are heteropolymers containing strings of amino acids. Structure of molecules means different things in different contexts. In inorganic chemistry, the structure invariably refers to the molecular formulae (e.g., NaCl, MgCl₂, etc.). Organic chemists always write a two dimensional view of the molecules while representing the structure of the molecules (e.g., benzene, naphthalene, etc.). Physicists conjure up the three dimensional views of molecular structures while biologists describe the protein structure at four levels. The sequence of amino acids i.e., the positional information in a protein – which is the first amino acid, which is second, and so on – is called the primary structure of a protein. A protein is imagined as a line, the left end represented by the first amino acid and the right end represented by the last amino
Which of the following statements regarding the primary structure of proteins and polypeptide formation are correct? S1: The linear sequence of amino acids defines the primary structure, providing positional information within the polypeptide chain. S2: The first amino acid in a protein is referred to as the C-terminal amino acid, while the last is the N-terminal amino acid. S3: Peptide bonds are formed between the carboxyl group of one amino acid and the amino group of another, releasing a water molecule. S4: Proteins are classified as homopolymers if they are composed of twenty different types of amino acids linked together. S5: While essential for determining higher-order structures, the primary structure alone typically ensures the protein's full biological activity.
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