Question

structure of a protein. a primary structure folds to form shapes, called secondary structures, like alpha helices and and beta sheets. in some proteins, multiple secondary structures can form along a single polypeptide chain. the types of amino acids in the chain determine which secondary structures will form. the model below shows parts of the primary and secondary structures of a protein. image of primary structure (polypeptide chain) and secondary structures (alpha helix, beta sheet) select the true statement. all proteins have the same secondary structures. a primary structure forms when a secondary structure folds into a shape. the types of amino acids in a polypeptide determine the shape of its secondary structure.

Explanation:

• For the first option: Different proteins have different amino acid sequences, so their secondary structures (like alpha helices, beta sheets) vary. So "All proteins have the same secondary structures" is false.
• For the second option: The primary structure (polypeptide chain) forms first, and then secondary structures form from the primary structure. So "A primary structure forms when a secondary structure folds into a shape" is false.
• For the third option: The passage states "The types of amino acids in the chain determine which secondary structures will form", so this statement matches the information and is true.

Answer:

The types of amino acids in a polypeptide determine the shape of its secondary structure.