Which type of proteins exhibit only primary and secondary structure?

two bonds that can rotate in space between each amino acid in the backbone of the primary sequence. These restricted movements, when repeated through several amino acids in a chain, yield the two main types of protein secondary structure: the alpha (α) helix and the beta (β) strand.

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Explanation:

i believe the correct answer from the choices listed above is the first option. the scientists need to look at the   validity of data, claims, hypotheses, and observations before  developing an argument. they base their arguments on facts that are present and they make sure they have proofs. 

explanation: